Difference between revisions of "IFF FORM and Chunk Registry"

Latest revision as of 20:49, 17 April 2014

IFF FORM and Chunk Registry

Last Updated: June 8, 2012

This section contains the official list of registered FORM and Chunk names that are reserved and in use. This list is often referred to as the 3rd party registry since these are FORM and Chunk types created by application developers and not part of the original IFF specification.

For all FORM and Chunk types that are public, the official specifications from the third party company are listed (in alphabetical order). At the end of this section are additional documents describing how the ILBM FORM type works on the Amiga.

New chunks and FORMS should be registered with the AmigaOS development team. Please make all submissions via the AmigaOS web site contact form.

Developing New IFF FORMs and Chunks

IFF has been one of the keys to the Amiga's superiority in multimedia applications, allowing interchange of media elements between packages. The wealth of standard IFF FORMs and chunks gives the Amiga user data-sharing capabilities that are virtually unequaled on other systems. The Amiga's ability to render an image, touch it up, convert it to a different display mode, and load it into in another package is something that is a chore on other platforms, simply because the format of the image file may be different from one application to the next. IFF files lessen the need for "conversion" software, because most Amiga applications can read and write them.

Since its introduction as an open standard in 1985, IFF has widened to encompass data of many sorts-and the need for new IFF types continues to grow. To satisfy these growing needs, developers will continue to define and support new IFF types.

When developing a new IFF type, there are several steps you should follow:

Discuss needs and specifications within the developer community and with the AmigaOS development team.

The most important thing about designing IFF FORMs and chunks is that they meet the data storage and transfer needs of multiple applications. When more than one product uses the same IFF type, the market widens for all products that use that IFF type. Users are not forced to use one product or another, but can buy as many as they need to get the job done, fully utilizing all the features that each product has to offer. This step helps to ensure that a proposed IFF form or chunk type is flexible and isn't redundant.

Implement the new type and conduct feasibility tests.

Before settling on a format, set up prototype code to test the proposed format. This will help to prove that the idea is sound and can be implemented in software before others try to use it.

Submit specifications to the AmigaOS development team.

Coming up with a new kind of IFF FORM or chunk is easy--almost too easy. Just about anyone can follow the IFF guidelines and define their own FORM or chunk. If every application used a different IFF FORM, one application would be unable to share data with another because it can't read the other application's IFF FORM. It's like making up a new word for something that everyone sees every day. You may understand what the word means, but when you try to use your new word to communicate with others, they won't understand you. Further, deciding to use a pre-existing FORM or chunk in a new and different way is a lot like making up your own meaning for a pre-existing word. Confusion results when programs try to read FORMs or chunks whose meaning was altered by a non-conforming program.

To avoid the problem of incompatible IFF types, register your new IFF types with the AmigaOS development team. The AmigaOS development team acts as a "dictionary" of IFF types. By submitting your proposals for FORM or chunk types to Amigan Software, you help prevent duplication of an existing data type. Also, if you register your new IFF type, it is more likely that it will be adopted as an IFF standard that other applications will use. For example, the ANIM form came from third party developers who proposed and refined the format. Now ANIM is the de facto standard for animation files.

For an excellent example of a third party FORM specification, see the WORD FORM. For an example of chunk descriptions, examine the 8SVX FORM's SEQN and FADE chunks.

Note that even you don't plan to release the specifications of your FORM or chunk, you must still register the name with the AmigaOS development team. This is the only way to prevent name conflicts in IFF files. You should register your FORM and chunk names before finalizing your product and its documentation in case there is a name conflict with an existing IFF type.

Distribute final specifications to the developer community.

Once you have registered your FORM or chunk with the AmigaOS development team, you should release the specifications of the chunk to the developer community. Although the AmigaOS development team publishes FORMs and chunks online developers should not rely on this method to distribute their IFF type specification. One of the most efficient ways to distribute your specification is to include it in your application's documentation. Distributing the specification will increase the probability of your FORM or chunk becoming a standard.

Third party FORMs

The following is an alphabetical list of registered FORMs, generic chunks (shown as (any).chunkname), and registered new chunks for existing FORMs (shown as formname.chunkname). The center column describes where additional information on the FORM or chunk may be found. Items marked “EA IFF” are described in the main chapters of the EA IFF specs. Those marked “IFF TP” are described in the third-party specifications section. Items marked “propos” are submitted proposals, some of which are private. And items marked with “—” are private or yet unreleased specifications.

Chunk ID	Reference	Description
(any).ANNO	IFF Standard	EA IFF 85 generic annotation chunk
(any).AUTH	IFF Standard	EA IFF 85 generic author chunk
(any).CHRS	IFF Standard	EA IFF 85 generic character string chunk
(any).CSET	IFF_TP	chunk for specifying character set
(any).FRED	--	Private ASDG global chunk
(any).FVER	IFF_TP	chunk for 2.0 VERSION string of an IFF file
(any).HLID	IFF_TP	HotLink IDentification (Soft-Logik)
(any).INFO	propos	This chunk contains data usually found in a file's .info file
(any).JUNK	IFF_TP	Always ignore this chunk
(any).UTF8	IFF_TP	UTF-8 character text
(any).NAME	IFF Standard	EA IFF 85 generic name of art, music, etc. chunk
(any).TEXT	IFF Standard	EA IFF 85 generic unformatted ASCII text chunk
(any).(c)	IFF Standard	EA IFF 85 generic copyright text chunk
8SVX	EA_IFF	EA IFF 85 8-bit sound sample form
8SVX.CHAN.PAN	IFF_TP	Stereo chunks for 8SVX form
8SVX.SEQN.FADE	IFF_TP	Looping chunks for 8SVX form
ACBM	IFF_TP	Amiga Contiguous Bitmap form
AHAM	----	unregistered (???)
AHIM	private	AHI Modes
AHIM.AUDN	private	AUDio driver Name
AHIM.AUDD	private	AUDio driver Data
AHIM.AUDM	private	AUDio Mode
AIFF	IFF_TP	Audio 1-32 bit samples (Mac, Apple II, Synthia Pro)
AIFF.COMM	IFF_TP	Describes fundamental parameters of the sampled sound
AIFF.SSND	IFF_TP	Contains the actual sample frames
ANBM	IFF_TP	Animated bitmap form (Framer, Deluxe Video)
ANIM	IFF_TP	Cel animation form
ANIM.brush	IFF_TP	ANIM brush format
ANIM.op6	IFF_TP	Stereo (3D) animations
ANIM.op7	IFF_TP	Maximum playback speed and acceptable packing rates
ANIM.op8	IFF_TP	Maximum playback speed and acceptable packing rates. Easier to use than ANIM.op7
ARC	propos	archive format proposal (old)
ARES	----	unregistered (???)
ATXT	----	temporarily reserved
AVCF	private	AmigaVision Flow format (currently private)
BANK	----	Soundquest Editor/Librarian MIDI Sysex dump
BBSD	----	BBS Database, F. Patnaude, Jr., Phalanx Software
C100	----	Cloanto Italia private format
CAT	IFF Standard	EA IFF 85 group identifier
CELP	propos	For storage of compressed ZyXEL voice data (reserved)
CHBM	----	Chunky bitmap (name reserved by Eric Lavitsky)
CLIP	----	CAT CLIP to hold various formats in clipboard
CMUS	propos	Common MUsical Score
CPFM	----	Cloanto Personal FontMaker (doc in their manual)
DCCL	----	DCTV paint clip
DCPA	----	DCTV paint palette
DCTV	----	DCTV raw picture file
DECK	----	private format for Inovatronics CanDo
DEEP	IFF_TP	Chunky pixel image files (used in TV Paint)
DOC	----	unregistered (PageStream)
DR2D	IFF_TP	2D object standard format
DSDR	----	unregistered (DrawStudio)
DRAW	----	reserved by Jim Bayless, 12/90
DTYP	IFF_TP	DataTypes identification
EXEC	propos	Proposed form for executable (loadseg-able) code
FANT	IFF_TP	Fantavision movie format
FAX3	----	private GPSoftware FAX format, no longer used
FAXX.GPHD	IFF_TP	Additional header info for FAXX forms
FAXX	IFF_TP	Facsimile image form
FIGR	----	Deluxe Video - reserved
FILM	----	LIST FILM - For storing ILBMs with interleaved 8SVX audio
FNTR	IFF Standard	EA IFF 85 reserved for raster font
FNTV	IFF Standard	EA IFF 85 reserved for vector font
FORM	IFF Standard	EA IFF 85 group identifier
FTXT	IFF Standard	EA IFF 85 formatted text form
GRYP	propos	byteplane storage proposal (copyrighted)
GSCR	IFF Standard	EA IFF 85 reserved general music score
GMS	IFF_TP	Gesture and Motion Signal GMS Web Site
GUI	propos	user interface storage proposal (private)
HEAD	IFF_TP	Flow - New Horizons Software
ILBM	EA_IFF	EA IFF 85 raster bitmap form
ILBM.3DCM	----	reserved by Haitex
ILBM.3DPA	----	reserved by Haitex
ILBM.ASDG	----	private ASDG application chunk
ILBM.BHBA	----	private Photon Paint chunk (brushes)
ILBM.BHCP	----	private Photon Paint chunk (screens)
ILBM.BHSM	----	private Photon Paint chunk
ILBM.CLUT	IFF_TP	Color Lookup Table chunk
ILBM.CMYK	IFF_TP	Cyan, Magenta, Yellow, & Black color map (Soft-Logik)
ILBM.CNAM	IFF_TP	Color naming chunk (Soft-Logik)
ILBM.CTBL.DYCP	IFF_TP	Newtek Dynamic HAM color chunks
ILBM.DCTV	----	reserved
ILBM.DGVW	----	private Newtek DigiView chunk
ILBM.DPI	IFF_TP	Dots per inch chunk
ILBM.DPPV	IFF_TP	DPaint perspective chunk (EA)
ILBM.DRNG	IFF_TP	DPaint IV enhanced color cycle chunk (EA)
ILBM.EPSF	IFF_TP	Encapsulated Postscript chunk
ILBM.PCHG	IFF_TP	Line by line palette control information (Sebastiano Vigna)
ILBM.PRVW	propos	A mini duplicate ILBM used for preview (Gary Bonham)
ILBM.TMAP	----	Transparency map (temporarily reserved)
VTAG	propos	Viewmode tags chunk suggestion
ILBM.XBMI	IFF_TP	eXtended BitMap Information (Soft-Logik)
ILBM.XSSL	IFF_TP	Identifier chunk for 3D X-Specs image (Haitex)
IOBJ	----	reserved by Seven Seas Software
IODK	----	reserved for Jean-Marc Porchet at Merging Technologies
ITRF	----	reserved
JMOV	----	reserved for Merging Technologies
LIST	IFF Standard	EA IFF 85 group identifier
MFAX	----	reserved for TKR GmbH & Co.
MIDI	----	Circum Design
MOVI	----	LIST MOVI - private format
MSCX	----	private Music-X format
MSMP	----	temporarily reserved
MTRX	IFF_TP	Numerical data storage (MathVision - Seven Seas)
NSEQ	----	Numerical sequence (Stockhausen GmbH)
OB3D	propos	Proposal for a standard 3D object format
OCMP	IFF Standard	EA IFF 85 reserved computer prop
OCPU	IFF Standard	EA IFF 85 reserved processor prop
OPGM	IFF Standard	EA IFF 85 reserved program prop
OSN	IFF Standard	EA IFF 85 reserved serial num. prop
PGTB	IFF_TP	Program traceback (SAS Institute)
PICS	IFF Standard	EA IFF 85 reserved Macintosh picture
PLBM	IFF Standard	EA IFF 85 reserved obsolete name
PMBC	propos	reserved for Black Belt Systems 91.12.01
PREF	----	Reserved by the AmigaOS Development Team for user preferences data, currently private
PREF.AHIG	private	AHI Global preferences
PREF.AHIU	private	AHI Unit preferences
PROP	IFF Standard	EA IFF 85 group identifier
PRSP	IFF_TP	DPaint IV perspective move form (EA)
PTCH	----	Patch file format (SAS Institute)
PTXT	----	temporarily reserved
RGB4	----	4-bit RGB (format not available)
RGBN and RGB8	IFF_TP	RGB image forms, Turbo Silver (Impulse)
RGBX	----	temporarily reserved
ROXN	----	private animation form
SAMP	IFF_TP	Sampled sound format
SC3D	----	private scene format (Sculpt-3D)
SHAK	----	private Shakespeare format
SHO1	----	reserved by Gary Bonham (private)
SHOW	----	reserved by Gary Bonham (private)
SMUS	EA_IFF	EA IFF 85 simple music score form
SPLT	IFF_TP	ASDG's file SPLiTting system
SSRE	----	reserved for Merging Technologies 92.05.04
SWRT	----	unregistered (???)
SYTH	----	SoundQuest Master Librarian MIDI System driver
TCDE	----	reserved by Merging Technologies
TDDD	IFF_TP	3D rendering data, Turbo Silver (Impulse)
TERM	----	unregistered (???)
TMUI	IFF_TP	Toolmaker IFF project file format (ToolMaker V1.19)
TREE	IFF_TP	Storage of arbitrary data structures as trees (or nested lists)
TRKR	propos	TRacKeR style music module format proposal
UNAM	IFF Standard	EA IFF 85 reserved user name prop
USCR	IFF Standard	EA IFF 85 reserved Uhuru score
UVOX	IFF Standard	EA IFF 85 reserved Uhuru Mac voice
VDEO	----	private Deluxe Video format
WORD	IFF_TP	ProWrite document format (New Horizons)
WOWO	----	unregistered (Wordworth)
YAFA	----	unregistered animation format (Wildfire)
YUVN	IFF_TP	For storage of Y:U:V image data (MacroSystems)

Difference between revisions of "IFF FORM and Chunk Registry"

Latest revision as of 20:49, 17 April 2014

IFF FORM and Chunk Registry

Developing New IFF FORMs and Chunks

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@@ Line 1: / Line 1: @@
 == IFF FORM and Chunk Registry ==
+'''Last Updated: June 8, 2012'''
-This section contains the official list of registered FORM and Chunk names that are reserved and in use. This list is often referred to as the 3rd party registry since these are FORM and Chunk types created by application developers and not part of the original IFF specification created by Electronic Arts and Commodore.
+This section contains the official list of registered FORM and Chunk names that are reserved and in use. This list is often referred to as the 3rd party registry since these are FORM and Chunk types created by application developers and not part of the original IFF specification.
 For all FORM and Chunk types that are public, the official specifications from the third party company are listed (in alphabetical order). At the end of this section are additional documents describing how the ILBM FORM type works on the Amiga.
-New chunks and FORMS should be registered with the AmigaOS development team. Please make all submissions via the [http://www.amigaos.net| AmigaOS web site] contact form.
+New chunks and FORMS should be registered with the AmigaOS development team. Please make all submissions via the [http://www.amigaos.net AmigaOS web site] contact form.
-== Third party FORMs ==
+== Developing New IFF FORMs and Chunks ==
+IFF has been one of the keys to the Amiga's superiority in multimedia
-The following is an alphabetical list of registered FORMs, generic chunks (shown as (any).chunkname), and registered new chunks for existing FORMs (shown as formname.chunkname). The center column describes where additional information on the FORM or chunk may be found. Items marked “EA IFF” are described in the main chapters of the EA IFF specs. Those marked “IFF TP” are described in the third-party specications section. Items marked “propos” are submitted proposals, some of which are private. And items marked with “—” are private or yet unreleased specifications.
+applications, allowing interchange of media elements between packages.
+The wealth of standard IFF FORMs and chunks gives the Amiga user
+data-sharing capabilities that are virtually unequaled on other systems.
+The Amiga's ability to render an image, touch it up, convert it to a
+different display mode, and load it into in another package is something
+that is a chore on other platforms, simply because the format of the image
+file may be different from one application to the next. IFF files lessen
+the need for "conversion" software, because most Amiga applications can
+read and write them.
+Since its introduction as an open standard in 1985, IFF has widened to
+encompass data of many sorts-and the need for new IFF types continues to
+grow. To satisfy these growing needs, developers will continue to define
+and support new IFF types.
+When developing a new IFF type, there are several steps you should follow:
-{| class="wikitable"
-| (any).ANNO || EA IFF || EA IFF 85 Generic Annotation chunk
-|-
-| (any).AUTH || EA IFF || EA IFF 85 Generic Author chunk
-|-
-| (any).CHRS || EA IFF || EA IFF 85 Generic character string chunk
-|-
-| (any).CSET.doc || IFF TP || chunk for specifying character set
-|-
-| (any).FVER.doc || IFF TP || chunk for 2.0 VERSION string of an IFF file
-|}
+; Discuss needs and specifications within the developer community and with the AmigaOS development team.
-(any).HLID.doc &amp; — &amp; HotLink IDentification (Contact CATS for info)<br />
-(any).NAME &amp; EA IFF &amp; EA IFF 85 Generic Name of art, music, etc. chunk<br />
-(any).TEXT &amp; EA IFF &amp; EA IFF 85 Generic unformatted ASCII text chunk<br />
-(any).(c) &amp; EA IFF &amp; EA IFF 85 Generic Copyright text chunk<br />
-SVX &amp; EA IFF &amp; EA IFF 85 8-bit sound sample form<br />
-SVX.CHAN.PAN.doc &amp; IFF TP &amp; Stereo chunks for 8SVX form<br />
-SVX.SEQN.FADE.doc &amp; IFF TP &amp; Looping chunks for 8SVX form<br />
-ACBM.doc &amp; IFF TP &amp; Amiga Contiguous Bitmap form<br />
-AHAM &amp; — &amp; unregistered (???)<br />
-AIFF.doc &amp; IFF TP &amp; Audio 1-32 bit samples (Mac,AppleII,Synthia Pro)<br />
-ANBM.doc &amp; IFF TP &amp; Animated bitmap form (Framer, Deluxe Video)<br />
-ANIM.brush.doc &amp; IFF TP &amp; ANIM brush format<br />
-ANIM.doc &amp; IFF TP &amp; Cel animation form<br />
-ANIM.op6.doc &amp; IFF TP &amp; Stereo (3D) Animations<br />
-ARC.proposal &amp; propos &amp; archive format proposal (old)<br />
-ARES &amp; — &amp; unregistered (???)<br />
-ATXT &amp; — &amp; temporariliy reserved<br />
-AVCF &amp; — &amp; AmigaVision flow (format not yet released)<br />
-AVCF.doc &amp; IFF TP<br />
-AVCO &amp; — &amp; AmigaVision commands (format not yet released)<br />
-AVEV &amp; — &amp; AmigaVision events (format not yet released)<br />
-BANK &amp; — &amp; Soundquest Editor/Librarian MIDI Sysex dump<br />
-BBSD &amp; — &amp; BBS Database, F.Patnaude,Jr., Phalanx Software<br />
-C100 &amp; — &amp; Cloanto Italia private format<br />
-CAT &amp; EA IFF &amp; EA IFF 85 group identifier<br />
-CHBM &amp; — &amp; Chunky bitmap (name reserved by Eric Lavitsky)<br />
-CLIP &amp; — &amp; CAT CLIP to hold various formats in clipboard<br />
-CPFM &amp; — &amp; Cloanto Personal FontMaker (doc in their manual)<br />
-DCCL &amp; — &amp; DCCL - DCTV paint clip<br />
-DCPA &amp; — &amp; DCPA - DCTV paint palette<br />
-DCTV &amp; — &amp; DCTV - DCTV raw picture file<br />
-DECK &amp; — &amp; private format for Inovatronics CanDo<br />
-DR2D.doc &amp; IFF TP &amp; 2-D Object standard format<br />
-DRAW &amp; — &amp; reserved by Jim Bayless, 12/90<br />
-FANT.doc &amp; IFF TP &amp; Fantavision movie format<br />
-FIGR &amp; — &amp; Deluxe Video - reserved<br />
-FNTR &amp; EA IFF &amp; EA IFF 85 reserved for raster font<br />
-FNTV &amp; EA IFF &amp; EA IFF 85 reserved for vector font<br />
-FORM &amp; EA IFF &amp; EA IFF 85 group identifier<br />
+: The most important thing about designing IFF FORMs and chunks is that they meet the data storage and transfer needs of multiple applications. When more than one product uses the same IFF type, the market widens for all products that use that IFF type. Users are not forced to use one product or another, but can buy as many as they need to get the job done, fully utilizing all the features that each product has to offer. This step helps to ensure that a proposed IFF form or chunk type is flexible and isn't redundant.
+; Implement the new type and conduct feasibility tests.
-<table>
-<tbody>
-<tr class="odd">
-<td align="left">FTXT</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 formatted text form</td>
-</tr>
-<tr class="even">
-<td align="left">GRYP.proposal</td>
-<td align="left">propos</td>
-<td align="left">byteplane storage proposal (copyrighted)</td>
-</tr>
-<tr class="odd">
-<td align="left">GSCR</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved gen. music score</td>
-</tr>
-<tr class="even">
-<td align="left">GUI.proposal</td>
-<td align="left">propos</td>
-<td align="left">user interface storage proposal (private)</td>
-</tr>
-<tr class="odd">
-<td align="left">HEAD.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Flow - New Horizons Software</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 raster bitmap form</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.3DCM</td>
-<td align="left">—</td>
-<td align="left">reserved by Haitex</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.3DPA</td>
-<td align="left">—</td>
-<td align="left">reserved by Haitex</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.ASDG</td>
-<td align="left">—</td>
-<td align="left">private ASDG application chunk</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.BHBA</td>
-<td align="left">—</td>
-<td align="left">private Photon Paint chunk (brushes)</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.BHCP</td>
-<td align="left">—</td>
-<td align="left">private Photon Paint chunk (screens)</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.BHSM</td>
-<td align="left">—</td>
-<td align="left">private Photon Paint chunk</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.CLUT.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Color Lookup Table chunk</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.CMYK.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Cyan, Magenta, Yellow &amp; Black cmap (Contact CATS)</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.CNAM.doc</td>
-<td align="left">—</td>
-<td align="left">Color naming chunk (Soft-Logik) (Contact CATS)</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.CTBL.DYCP.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Newtek Dynamic Ham color chunks</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.DCTV</td>
-<td align="left">—</td>
-<td align="left">reserved</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.DGVW</td>
-<td align="left">—</td>
-<td align="left">private Newtek DigiView chunk</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.DPI.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Dots per inch chunk</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.DPPV.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">DPaint perspective chunk (EA)</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.DRNG.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">DPaint IV enhanced color cycle chunk (EA)</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.EPSF.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Encapsulated Postscript chunk</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.TMAP</td>
-<td align="left">—</td>
-<td align="left">Transparency map (temporarily reserved)</td>
-</tr>
-<tr class="even">
-<td align="left">ILBM.VTAG.proposal</td>
-<td align="left">propos</td>
-<td align="left">Viewmode tags chunk suggestion</td>
-</tr>
-<tr class="odd">
-<td align="left">ILBM.XBMI.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">eXtended BitMap Information (Contact CATS)</td>
-</tr>
-<tr class="even">
-<td align="left">IOBJ</td>
-<td align="left">—</td>
-<td align="left">reserved by Seven Seas Software</td>
-</tr>
-<tr class="odd">
-<td align="left">ITRF</td>
-<td align="left">—</td>
-<td align="left">reserved</td>
-</tr>
-<tr class="even">
-<td align="left">LIST</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 group identifier</td>
-</tr>
-<tr class="odd">
-<td align="left">MIDI</td>
-<td align="left">—</td>
-<td align="left">Circum Design</td>
-</tr>
-<tr class="even">
-<td align="left">MOVI</td>
-<td align="left">—</td>
-<td align="left">LIST MOVI - private format</td>
-</tr>
-<tr class="odd">
-<td align="left">MSCX</td>
-<td align="left">—</td>
-<td align="left">private Music-X format</td>
-</tr>
-<tr class="even">
-<td align="left">MSMP</td>
-<td align="left">—</td>
-<td align="left">temporarily reserved</td>
-</tr>
-<tr class="odd">
-<td align="left">MTRX.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Numerical data storage (MathVision - Seven Seas)</td>
-</tr>
-<tr class="even">
-<td align="left">NSEQ</td>
-<td align="left">—</td>
-<td align="left">Numerical sequence (Stockhausen GmbH)</td>
-</tr>
-<tr class="odd">
-<td align="left">OCMP</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved computer prop</td>
-</tr>
-<tr class="even">
-<td align="left">OCPU</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved processor prop</td>
-</tr>
-<tr class="odd">
-<td align="left">OPGM</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved program prop</td>
-</tr>
-<tr class="even">
-<td align="left">OSN</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved serial num prop</td>
-</tr>
-<tr class="odd">
-<td align="left">PGTB.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Program traceback (SAS Institute)</td>
-</tr>
-<tr class="even">
-<td align="left">PICS</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved Macintosh picture</td>
-</tr>
-<tr class="odd">
-<td align="left">PLBM</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved obsolete name</td>
-</tr>
-<tr class="even">
-<td align="left">PROP</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 group identifier</td>
-</tr>
-<tr class="odd">
-<td align="left">PRSP.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">DPaint IV perspective move form (EA)</td>
-</tr>
-<tr class="even">
-<td align="left">PTCH</td>
-<td align="left">—</td>
-<td align="left">Patch file format (SAS Institute)</td>
-</tr>
-<tr class="odd">
-<td align="left">PTXT</td>
-<td align="left">—</td>
-<td align="left">temporarily reserved</td>
-</tr>
-<tr class="even">
-<td align="left">RGB4</td>
-<td align="left">—</td>
-<td align="left">4-bit RGB (format not available)</td>
-</tr>
-<tr class="odd">
-<td align="left">RGBN-RGB8.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">RGB image forms, Turbo Silver (Impulse)</td>
-</tr>
-<tr class="even">
-<td align="left">RGBX</td>
-<td align="left">—</td>
-<td align="left">temporarily reserved</td>
-</tr>
-<tr class="odd">
-<td align="left">ROXN</td>
-<td align="left">—</td>
-<td align="left">private animation form</td>
-</tr>
-<tr class="even">
-<td align="left">SAMP.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">Sampled sound format</td>
-</tr>
-<tr class="odd">
-<td align="left">SC3D</td>
-<td align="left">—</td>
-<td align="left">private scene format (Sculpt-3D)</td>
-</tr>
-<tr class="even">
-<td align="left">SHAK</td>
-<td align="left">—</td>
-<td align="left">private Shakespeare format</td>
-</tr>
-<tr class="odd">
-<td align="left">SHO1</td>
-<td align="left">—</td>
-<td align="left">Reserved by Gary Bonham (private)</td>
-</tr>
-</tbody>
-</table>
+: Before settling on a format, set up prototype code to test the proposed format. This will help to prove that the idea is sound and can be implemented in software before others try to use it.
-<table>
-<tbody>
-<tr class="odd">
-<td align="left">SHOW</td>
-<td align="left">—</td>
-<td align="left">Reserved by Gary Bonham (private)</td>
-</tr>
-<tr class="even">
-<td align="left">SMUS</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 simple music score form</td>
-</tr>
-<tr class="odd">
-<td align="left">SYTH</td>
-<td align="left">—</td>
-<td align="left">SoundQuest Master Librarian MIDI System driver</td>
-</tr>
-<tr class="even">
-<td align="left">TCDE</td>
-<td align="left">—</td>
-<td align="left">reserved by Merging Technologies</td>
-</tr>
-<tr class="odd">
-<td align="left">TDDD.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">3-D rendering data, Turbo Silver (Impulse)</td>
-</tr>
-<tr class="even">
-<td align="left">UNAM</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved user name prop</td>
-</tr>
-<tr class="odd">
-<td align="left">USCR</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved Uhuru score</td>
-</tr>
-<tr class="even">
-<td align="left">UVOX</td>
-<td align="left">EA IFF</td>
-<td align="left">EA IFF 85 reserved Uhuru Mac voice</td>
-</tr>
-<tr class="odd">
-<td align="left">VDEO</td>
-<td align="left">—</td>
-<td align="left">private Deluxe Video format</td>
-</tr>
-<tr class="even">
-<td align="left">WORD.doc</td>
-<td align="left">IFF TP</td>
-<td align="left">ProWrite document format (New Horizons)</td>
-</tr>
-</tbody>
-</table>
+; Submit specifications to the AmigaOS development team.
-=== Chunk for specifying character set ===
+: Coming up with a new kind of IFF FORM or chunk is easy--almost too easy. Just about anyone can follow the IFF guidelines and define their own FORM or chunk. If every application used a different IFF FORM, one application would be unable to share data with another because it can't read the other application's IFF FORM. It's like making up a new word for something that everyone sees every day. You may understand what the word means, but when you try to use your new word to communicate with others, they won't understand you. Further, deciding to use a pre-existing FORM or chunk in a new and different way is a lot like making up your own meaning for a pre-existing word. Confusion results when programs try to read FORMs or chunks whose meaning was altered by a non-conforming program.
-<pre>chunk for specifying character set
+: To avoid the problem of incompatible IFF types, register your new IFF types with the AmigaOS development team. The AmigaOS development team acts as a "dictionary" of IFF types. By submitting your proposals for FORM or chunk types to Amigan Software, you help prevent duplication of an existing data type. Also, if you register your new IFF type, it is more likely that it will be adopted as an IFF standard that other applications will use. For example, the ANIM form came from third party developers who proposed and refined the format. Now ANIM is the de facto standard for animation files.
-Registered by Martin Taillefer.
+: For an excellent example of a third party FORM specification, see the WORD FORM. For an example of chunk descriptions, examine the 8SVX FORM's SEQN and FADE chunks.
-A chunk for use in any FORM, to specify character set used for
-text in FORM.
+: Note that even you don't plan to release the specifications of your FORM or chunk, you must still register the name with the AmigaOS development team. This is the only way to prevent name conflicts in IFF files. You should register your FORM and chunk names before finalizing your product and its documentation in case there is a name conflict with an existing IFF type.
+; Distribute final specifications to the developer community.
-struct CSet {
-        LONG    CodeSet;        /* 0=ECMA Latin 1 (std Amiga charset) */
-                                /* CBM will define additional values  */
-        LONG    Reserved[7];
-        }</pre>
-=== Chunk for 2.0 VERSION string of an IFF file ===
+: Once you have registered your FORM or chunk with the AmigaOS development team, you should release the specifications of the chunk to the developer community. Although the AmigaOS development team publishes FORMs and chunks online developers should not rely on this method to distribute their IFF type specification. One of the most efficient ways to distribute your specification is to include it in your application's documentation. Distributing the specification will increase the probability of your FORM or chunk becoming a standard.
-<pre>chunk for 2.0 VERSION string of an IFF file
+== Third party FORMs ==
-Registered by Martin Taillefer.
+: The following is an alphabetical list of registered FORMs, generic chunks (shown as (any).chunkname), and registered new chunks for existing FORMs (shown as formname.chunkname). The center column describes where additional information on the FORM or chunk may be found. Items marked “EA IFF” are described in the main chapters of the EA IFF specs. Those marked “IFF TP” are described in the third-party specifications section. Items marked “propos” are submitted proposals, some of which are private. And items marked with “—” are private or yet unreleased specifications.
-A chunk for use in any FORM, to contain standard 2.0 version string.
+{| class="wikitable"
-$VER: name ver.rev
+! Chunk ID
+! Reference
-where &quot;name&quot; is the name or identifier of the file
+! Description
-and ver.rev is a version/revision such as 37.1
+|-
+| (any).ANNO
-Example:
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 generic annotation chunk
-$VER: workbench.catalog 37.42</pre>
+|-
-=== Stereo chunks for 8SVX form ===
+| (any).AUTH
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 generic author chunk
+|-
-<pre>                     SMUS.CHAN and SMUS.PAN Chunks
+| [[FTXT_IFF_Formatted_Text#Data_Chunk_CHRS|(any).CHRS]]
-            Stereo imaging in the &quot;8SVX&quot; IFF 8-bit Sample Voice
+| [[IFF_Standard|IFF Standard]]
-            ---------------------------------------------------
+| EA IFF 85 generic character string chunk
-                 Registered by David Jones, Gold Disk Inc.
+|-
+| [[CSET_IFF_Text_Character_Set|(any).CSET]]
-There are two ways to create stereo imaging when playing back a digitized
+| IFF_TP
-sound. The first relies on the original sound being created with a stereo
+| chunk for specifying character set
-sampler: two different samples are digitized simultaneously, using right and
+|-
-left inputs. To play back this type of sample while maintaining the
+| (any).FRED
-stereo imaging, both channels must be set to the same volume. The second type
+| --
-of stereo sound plays the identical information on two different channels at
+| Private ASDG global chunk
-different volumes. This gives the sample an absolute position in the stereo
+|-
-field. Unfortunately, there are currently a number of methods for doing this
+| [[FVER_IFF_Version_String|(any).FVER]]
-currently implemented on the Amiga, none truly adhering to any type of
+| IFF_TP
-standard. What I have tried to to is provide a way of doing this
+| chunk for 2.0 VERSION string of an IFF file
-consistently, while retaining compatibility with existing (non-standard)
+|-
-systems. Introduced below are two optional data chunks, CHAN and PAN. CHAN
+| [[HLID_IFF_Hotlink_Identification|(any).HLID]]
-deals with sounds sampled in stereo, and PAN with samples given stereo
+| IFF_TP
-characteristics after the fact.
+| HotLink IDentification (Soft-Logik)
+|-
+| [[INFO_IFF_Icon_Information|(any).INFO]]
-Optional Data Chunk CHAN
+| propos
-________________________
+| This chunk contains data usually found in a file's .info file
+|-
-This chunk is already written by the software for a popular stereo sampler. To
+| [[JUNK_IFF_Junk_Data|(any).JUNK]]
-maintain the ability read these samples, its implementation here is
+| IFF_TP
-therefore limited to maintain compatability.
+| Always ignore this chunk
+|-
-The optional data chunk CHAN gives the information neccessary to play a
+| [[UTF8_IFF_UTF-8_Unicode_Text|(any).UTF8]]
-sample on a specified channel, or combination of channels. This chunk
+| IFF_TP
-would be useful for programs employing stereo recording or playback of sampled
+| UTF-8 character text
-sounds.
+|-
+| (any).NAME
-        #define RIGHT           4L
+| [[IFF_Standard|IFF Standard]]
-        #define LEFT            2L
+| EA IFF 85 generic name of art, music, etc. chunk
-        #define STEREO          6L
+|-
+| (any).TEXT
-        #define ID_CHAN MakeID('C','H','A','N')
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 generic unformatted ASCII text chunk
-        typedef sampletype LONG;
+|-
+| (any).(c)
-If &quot;sampletype&quot; is RIGHT, the program reading the sample knows that it was
+| [[IFF_Standard|IFF Standard]]
-originally intended to play on a channel routed to the right speaker,
+| EA IFF 85 generic copyright text chunk
-(channels 1 and 2 on the Amiga). If &quot;sampletype&quot; is LEFT, the left speaker
+|-
-was intended (Amiga channels 0 and 3). It is left to the discretion of the
+| [[8SVX_IFF_8-Bit_Sampled_Voice|8SVX]]
-programmer to decide whether or not to play a sample when a channel on the
+| EA_IFF
-side designated by &quot;sampletype&quot; cannot be allocated.
+| EA IFF 85 8-bit sound sample form
+|-
-If &quot;sampletype&quot; is STEREO, then the sample requires a pair of channels routed
+| [[8SVX_IFF_8-Bit_Sampled_Voice#8SVX.CHAN.PAN|8SVX.CHAN.PAN]]
-to both speakers (Amiga pairs [0,1] and [2,3]). The BODY chunk for stereo
+| IFF_TP
-pairs contains both left and right information. To adhere to existing
+| Stereo chunks for 8SVX form
-conventions, sampling software should write first the LEFT information,
+|-
-followed by the RIGHT. The LEFT and RIGHT information should be equal in
+| [[8SVX_IFF_8-Bit_Sampled_Voice#8SVX.SEQN.FADE|8SVX.SEQN.FADE]]
-length.
+| IFF_TP
+| Looping chunks for 8SVX form
-Again, it is left to the programmer to decide what to do if a channel for
+|-
-a stereo pair can't be allocated; wether to play the available channel only,
+| [[ACBM_IFF_Amiga_Continuous_Bitmap|ACBM]]
-or to allocate another channels routed to the wrong speaker.
+| IFF_TP
+| Amiga Contiguous Bitmap form
+|-
+| AHAM
-Optional Data Chunk PAN
+| ----
-_______________________
+| unregistered (???)
+|-
-The optional data chunk PAN provides the neccessary information to create a
+| AHIM
-stereo sound using a single array of data. It is neccessary to replay the
+| private
-sample simultaneously on two channels, at different volumes.
+| AHI Modes
+|-
-        #define ID_PAN MakeID('P','A','N',' ')
+| AHIM.AUDN
+| private
-        typedef sposition Fixed; /* 0 &lt;= sposition &lt;= Unity */
+| AUDio driver Name
-                                                         /* Unity is elsewhere #defined as 10000L, and
+|-
-                                                          * refers to the maximum possible volume.
+| AHIM.AUDD
-                                                          * /
+| private
+| AUDio driver Data
-        /* Please note that 'Fixed' (elsewhere #defined as LONG) is used to
+|-
-         * allow for compatabilty between audio hardware of different resolutions.
+| AHIM.AUDM
-         */
+| private
+| AUDio Mode
-The 'sposition' variable describes a position in the stereo field. The
+|-
-numbers of discrete stereo positions available is equal to 1/2 the number of
+| [[AIFF_IFF_Audio_Samples#AIFF|AIFF]]
-discrete volumes for a single channel.
+| IFF_TP
+| Audio 1-32 bit samples (Mac, Apple II, Synthia Pro)
-The sample must be played on both the right and left channels. The overall
+|-
-volume of the sample is determined by the &quot;volume&quot; field in the Voice8Header
+| [[AIFF_IFF_Audio_Samples#AIFF|AIFF.COMM]]
-structure in the VHDR chunk.
+| IFF_TP
+| Describes fundamental parameters of the sampled sound
-The left channel volume = overall volume / (Unity / sposition).
+|-
- &quot;  right   &quot;       &quot;   = overall volume - left channel volume.
+| [[AIFF_IFF_Audio_Samples#AIFF|AIFF.SSND]]
+| IFF_TP
-For example:
+| Contains the actual sample frames
-        If sposition = Unity, the sample is panned all the way to the left.
+|-
-        If sposition = 0, the sample is panned all the way to the right.
+| [[ANBM_IFF_Animated_Bitmap|ANBM]]
-        If sposition = Unity/2, the sample is centered in the stereo field.</pre>
+| IFF_TP
-=== Looping chunks for 8SVX form ===
+| Animated bitmap form (Framer, Deluxe Video)
+|-
+| [[ANIM_IFF_CEL_Animations#ANIM|ANIM]]
+| IFF_TP
-<pre>                          SEQN and FADE Chunks
+| Cel animation form
+|-
+| [[ANIM_IFF_CEL_Animations#ANIM.brush|ANIM.brush]]
-       Multiple Loop Sequencing in the &quot;8SVX&quot; IFF 8-bit Sample Voice
+| IFF_TP
-            ---------------------------------------------------
+| ANIM brush format
-           Registered by Peter Norman, RamScan Software Pty Ltd.
+|-
+| [[ANIM_IFF_CEL_Animations#ANIM.op6|ANIM.op6]]
+| IFF_TP
+| Stereo (3D) animations
+|-
-Sound samples are notorious for demanding huge amounts of memory.
+| [[ANIM_IFF_CEL_Animations#ANIM.op7|ANIM.op7]]
+| IFF_TP
-While earlier uses of digital sound on the Amiga were mainly in the form of
+| Maximum playback speed and acceptable packing rates
-short looping waveforms for use as musical instruments, many people today
+|-
-wish to record several seconds (even minutes) of sound. This of course eats
+| [[ANIM_IFF_CEL_Animations#ANIM.op8|ANIM.op8]]
-memory.
+| IFF_TP
+| Maximum playback speed and acceptable packing rates. Easier to use than ANIM.op7
-Assuming that quite often the content of these recordings is music, and that
+|-
-quite often music contains several passages which repeat at given times,
+| ARC
-&quot;verse1 .. chorus ..  verse2 .. chorus ..&quot; etc, a useful extention has been
+| propos
-added to the 8SVX list of optional data chunks. It's purpose is to conserve
+| archive format proposal (old)
-memory by having the computer repeat sections rather than having several
+|-
-instances of a similar sound or musical passage taking up valuable sample
+| ARES
-space.
+| ----
+| unregistered (???)
+|-
-The &quot;SEQN&quot; chunk has been created to define &quot;Multiple&quot; loops or sections
+| ATXT
-within a single octave 8SVX MONO or STEREO waveform.
+| ----
+| temporarily reserved
-It is intended that a sampled sound player program which supports this chunk
+|-
-will play sections of the waveform sequentially in an order that the SEQN
+| AVCF
-chunk specifies. This means for example, if an identical chorus
+| private
-repeats throughout a recording, rather than have this chorus stored several
+| AmigaVision Flow format (currently private)
-times along the waveform, it is only necessary to have one copy of the chorus
+|-
-stored in the waveform.
+| BANK
+| ----
-A &quot;SEQeNce&quot; of definitions can then be set up to have the computer loop back
+| Soundquest Editor/Librarian MIDI Sysex dump
-and repeat the chorus at the required time. The remaining choruses
+|-
-stored in the waveform will no longer be necessary and can be removed.
+| BBSD
+| ----
+| BBS Database, F. Patnaude, Jr., Phalanx Software
-eg. If we had a recording of the following example, we would find that
+|-
-there are several parts which simply repeat. Substantial savings can be made
+| C100
-by having the computer repeat sections rather than have them stored in memory.
+| ----
+| Cloanto Italia private format
+|-
+| CAT
-EXAMPLE
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 group identifier
-&quot;Haaaallelujah....Haaaallelujah...Hallelujah..Hallelujah..Halleeeelujaaaah.&quot;
+|-
+| CELP
+| propos
+| For storage of compressed ZyXEL voice data (reserved)
-Applying a sequence to the above recording would look as follows.
+|-
+| CHBM
+| ----
-Haaaallelujah....Haaaallelujah...Hallelujah..Hallelujah..Halleeeelujaaaah.
+| Chunky bitmap (name reserved by Eric Lavitsky)
-[     Loop1     ]
+|-
-[     Loop2     ]
+| CLIP
-                                 [  Loop3   ]
+| ----
-                                 [  Loop4   ]
+| CAT CLIP to hold various formats in clipboard
-                                                         [     Loop5     ]
+|-
+| [[CMUS_IFF_Musical_Score#CMUS|CMUS]]
-                [   Dead Space   ]          [ Dead Space ]
+| propos
+| Common MUsical Score
+|-
-The DEAD SPACE can be removed. With careful editing of the multiple loop
+| CPFM
-positions, the passage can be made to sound exactly the same as the original
+| ----
-with far less memory required.
+| Cloanto Personal FontMaker (doc in their manual)
+|-
+| DCCL
+| ----
-Chunk Definitions...
+| DCTV paint clip
+|-
+| DCPA
+| ----
-Optional Data Chunk SEQN
+| DCTV paint palette
-________________________
+|-
+| DCTV
-The optional data chunk SEQN gives the information necessary to play a
+| ----
-sample in a sequence of defined blocks. To have a segment repeat twice,
+| DCTV raw picture file
-the definition occurs twice in the list.
+|-
+| DECK
-This list consists of pairs of ULONG &quot;loop start&quot; and &quot;end&quot; definitions which
+| ----
-are offsets from the start of the waveform. The locations or values must be
+| private format for Inovatronics CanDo
-LONGWORD aligned (divisable by 4).
+|-
+| [[DEEP_IFF_Chunky_Pixel_Image#DEEP|DEEP]]
+| IFF_TP
-To determine how many loop definitions in a given file, simply divide the
+| Chunky pixel image files (used in TV Paint)
-SEQN chunk size by 8.
+|-
+| DOC
-eg if chunk size == 40 ... number of loops  = (40 / 8) .. equals 5 loops.
+| ----
+| unregistered (PageStream)
+|-
-The raw data in a file might look like this...
+| [[DR2D_IFF_2-D_Objects#DR2D|DR2D]]
+| IFF_TP
+| 2D object standard format
+|-
-'S-E-Q-N' [ size ] [     Loop 1    ] [     Loop 2    ] [     Loop 3    ]
+| DSDR
+| ----
- 5345514E 00000028 00000000 00000C00 00000000 00000C00 00000C08 00002000
+| unregistered (DrawStudio)
-             ^
+|-
-             ^     'Haaaallelujah..' 'Haaaallelujah..'   'Hallelujah..'
+| DRAW
-             ^
+| ----
-             ^
+| reserved by Jim Bayless, 12/90
-bytes decimal / 8 = 5 loop or segments
+|-
+| [[DTYP_IFF_DataType_Identification|DTYP]]
+| IFF_TP
+| DataTypes identification
-       [     Loop 4    ] [    Loop 5     ]'B-O-D-Y'   Size     Data
+|-
+| [[EXEC_IFF_Executable_Code|EXEC]]
-C08 00002000 00002008 00003000 424F4459 000BE974 010101010101010
+| propos
+| Proposed form for executable (loadseg-able) code
-        'Hallelujah..'  'Halleeeelujah..'
+|-
+| [[FANT_IFF_Movie_Format|FANT]]
+| IFF_TP
+| Fantavision movie format
+|-
+| FAX3
-In a waveform containing SEQN chunks, the oneShotHiSamples should be set to 0
+| ----
-and the repeatHiSamples should equal the BODY length (divided by 2 if STEREO).
+| private GPSoftware FAX format, no longer used
+|-
-Remember the locations of the start and end of each segment or loop should
+| [[FAXX_IFF_Facsimile_Image#FAXX.GPHD|FAXX.GPHD]]
-be LONGWORD aligned.
+| IFF_TP
+| Additional header info for FAXX forms
+|-
-If the waveform is Stereo, treat the values and locations in exactly the same
+| [[FAXX_IFF_Facsimile_Image#FAXX|FAXX]]
-way. In other words, if a loop starts at location 400 within a Stereo
+| IFF_TP
-waveform, you start the sound at the 400th byte position in the left data
+| Facsimile image form
-and the 400th byte position in the right data simultaneously.
+|-
+| FIGR
+| ----
+| Deluxe Video - reserved
-        #define ID_SEQN MakeID('S','E','Q','N')
+|-
+| FILM
+| ----
+| LIST FILM - For storing ILBMs with interleaved 8SVX audio
+|-
+| FNTR
-Optional Data Chunk FADE
+| [[IFF_Standard|IFF Standard]]
-_______________________
+| EA IFF 85 reserved for raster font
+|-
+| FNTV
-The FADE chunk defines at what loop number the sound should begin to
+| [[IFF_Standard|IFF Standard]]
-fade away to silence. It is possible to finish a sample of music in much
+| EA IFF 85 reserved for vector font
-the same way as commercial music does today. A FADE chunk consists of
+|-
-one ULONG value which has a number in it. This number corresponds to the
+| FORM
-loop number at which the fade should begin.
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 group identifier
-eg. You may have a waveform containing 50 loops. A FADE definition of 45 will
+|-
-specify that once loop 45 is reached, fading to zero volume should begin.
+| [[FTXT_IFF_Formatted_Text|FTXT]]
-The rate at which this fade takes place is determined by the length of time
+| [[IFF_Standard|IFF Standard]]
-left to play. The playing software should do a calculation based on the
+| EA IFF 85 formatted text form
-following...
+|-
+| GRYP
+| propos
-Length of all remaining sequences including current sequence (in bytes)
+| byteplane storage proposal (copyrighted)
+|-
-divided by
+| GSCR
+| [[IFF_Standard|IFF Standard]]
-the current playback rate in samples per second
+| EA IFF 85 reserved general music score
+|-
-= time remaining.
+| [http://acroe.imag.fr/gms/docs/GMS_SPEC_V01.pdf GMS]
+| IFF_TP
+| Gesture and Motion Signal [http://acroe.imag.fr/gms/ GMS Web Site]
+|-
-Begin stepping the volume down at a rate which will hit zero volume just as
+| GUI
-the waveform finishes.
+| propos
+| user interface storage proposal (private)
+|-
+| [[HEAD_IFF_Flow_Idea_Processor_Format|HEAD]]
+| IFF_TP
+| Flow - New Horizons Software
+|-
+| [[ILBM_IFF_Interleaved_Bitmap|ILBM]]
-The raw data in a file may look like this.
+| EA_IFF
+| EA IFF 85 raster bitmap form
+|-
+| ILBM.3DCM
+| ----
- 'F-A-D-E'  [ Size ]   Loop No.  'B-O-D-Y'   Size   Data..
+| reserved by Haitex
+|-
-  46414445  00000004   0000002D   424F4459 000BE974 01010101 01010101 etc etc
+| ILBM.3DPA
-                          ^
+| ----
-                          Start fading when loop number 45 is reached.
+| reserved by Haitex
+|-
+| ILBM.ASDG
+| ----
+| private ASDG application chunk
-        #define ID_FADE MakeID('F','A','D','E')
+|-
+| ILBM.BHBA
+| ----
+| private Photon Paint chunk (brushes)
-Although order shouldn't make much difference, it is a general rule of thumb
+|-
-that SEQN should come before FADE and FADE should be last before the BODY.
+| ILBM.BHCP
+| ----
-Stereo waveforms would have CHAN,SEQN,FADE,BODY in that order.</pre>
+| private Photon Paint chunk (screens)
-=== Amiga Contiguous Bitmap ===
+|-
+| ILBM.BHSM
-<pre>Amiga Contiguous Bitmap form
+| ----
+| private Photon Paint chunk
-IFF FORM / CHUNK DESCRIPTION
+|-
-============================
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.CLUT|ILBM.CLUT]]
+| IFF_TP
-Form/Chunk ID:   FORM  ACBM  (Amiga Contiguous BitMap)
+| Color Lookup Table chunk
-                 Chunk ABIT  (Amiga BITplanes)
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.CMYK|ILBM.CMYK]]
-Date Submitted:  05/29/86
+| IFF_TP
-Submitted by:    Carolyn Scheppner   CBM
+| Cyan, Magenta, Yellow, &amp; Black color map (Soft-Logik)
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.CNAM|ILBM.CNAM]]
-FORM
+| IFF_TP
-====
+| Color naming chunk (Soft-Logik)
+|-
-FORM ID:  ACBM  (Amiga Contiguous BitMap)
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.CTBL.DYCP|ILBM.CTBL.DYCP]]
+| IFF_TP
-FORM Description:
+| Newtek Dynamic HAM color chunks
+|-
-   FORM ACBM has the same format as FORM ILBM except the normal BODY
+| ILBM.DCTV
-chunk (InterLeaved BitMap) is replaced by an ABIT chunk (Amiga BITplanes).
+| ----
+| reserved
-FORM Purpose:
+|-
+| ILBM.DGVW
-   To enable faster loading/saving of screens, especially from Basic,
+| ----
-while retaining the flexibility and portability of IFF format files.
+| private Newtek DigiView chunk
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.DPI|ILBM.DPI]]
-CHUNKS
+| IFF_TP
-======
+| Dots per inch chunk
+|-
-Chunk ID:   ABIT  (Amiga BITplanes)
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.DPPV|ILBM.DPPV]]
+| IFF_TP
-Chunk Description:
+| DPaint perspective chunk (EA)
+|-
-   The ABIT chunk contains contiguous bitplane data.  The chunk contains
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.DRNG|ILBM.DRNG]]
-sequential data for bitplane 0 through bitplane n.
+| IFF_TP
+| DPaint IV enhanced color cycle chunk (EA)
-Chunk Purpose:
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.EPSF|ILBM.EPSF]]
-   To enable loading/storing of bitmaps with one DOS Read/Write per
+| IFF_TP
-bitplane.  Significant speed increases are realized when loading/saving
+| Encapsulated Postscript chunk
-screens from Basic.
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.PCHG|ILBM.PCHG]]
+| IFF_TP
-SUPPORTING SOFTWARE
+| Line by line palette control information (Sebastiano Vigna)
-===================
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.PRVW|ILBM.PRVW]]
-(Public Domain, available soon via Fish PD disk, various networks)
+| propos
+| A mini duplicate ILBM used for preview (Gary Bonham)
-LoadILBM-SaveACBM (AmigaBasic)
+|-
-   Loads and displays an IFF ILBM pic file (Graphicraft, DPaint, Images).
+| ILBM.TMAP
-   Optionally saves the screen in ACBM format.
+| ----
+| Transparency map (temporarily reserved)
-LoadACBM (AmigaBasic)
+|-
-   Loads and display an ACBM format pic file.
+| VTAG
+| propos
-SaveILBM (AmigaBasic)
+| Viewmode tags chunk suggestion
-   Saves a demo screen as an ILBM pic file which can be loaded into
+|-
-   Graphicraft, DPaint, Images.</pre>
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.XBMI|ILBM.XBMI]]
-=== Audio Interchange File Format File ===
+| IFF_TP
+| eXtended BitMap Information (Soft-Logik)
-<pre>Audio 1-32 bit samples (Mac,AppleII,Synthia Pro)
+|-
+| [[ILBM_IFF_Interleaved_Bitmap#ILBM.XSSL|ILBM.XSSL]]
-provided by Steve Milne and Matt Deatherage, Apple Computer, Inc.
+| IFF_TP
+| Identifier chunk for 3D X-Specs image (Haitex)
-AIFF: Audio Interchange File Format File
+|-
-----------------------------------------
+| IOBJ
+| ----
-The Audio Interchange File Format (Audio IFF) provides a standard for storing
+| reserved by Seven Seas Software
-sampled sounds.  The format is quite flexible, allowing the storage of
+|-
-monaural or multichannel sampled sounds at a variety of sample rates and
+| IODK
-sample widths.
+| ----
+| reserved for Jean-Marc Porchet at Merging Technologies
-Audio IFF conforms to the &quot;`EA IFF 85' Standard for Interchange Format Files&quot;
+|-
-developed by Electronic Arts.
+| ITRF
+| ----
-Audio IFF is primarily an interchange format, although application designers
+| reserved
-should find it flexible enough to use as a data storage format as well.  If an
+|-
-application does choose to use a different storage format, it should be able
+| JMOV
-to convert to and from the format defined in this document.  This ability to
+| ----
-convert will facilitate the sharing of sound data between applications.
+| reserved for Merging Technologies
+|-
-Audio IFF is the result of several meetings held with music developers over a
+| LIST
-period of ten months during 1987 and 1988.  Apple Computer greatly appreciates
+| [[IFF_Standard|IFF Standard]]
-the comments and cooperation provided by all developers who helped define this
+| EA IFF 85 group identifier
-standard.
+|-
+| MFAX
-Another &quot;EA IFF 85&quot; sound storage format is &quot;`8SVX' IFF 8-bit Sampled Voice&quot;,
+| ----
-by Electronic Arts.  &quot;8SVX,&quot; which handles eight-bit monaural samples, is
+| reserved for TKR GmbH &amp; Co.
-intended mainly for storing sound for playback on personal computers.  Audio
+|-
-IFF is intended for use with a larger variety of computers, sampled sound
+| MIDI
-instruments, sound software applications, and high fidelity recording devices.
+| ----
+| Circum Design
-Data Types
+|-
+| MOVI
-A C-like language will be used to describe the data structures in this document
+| ----
-The data types used are listed below.
+| LIST MOVI - private format
+|-
-  char:           8 bits signed.  A char can contain more than just ASCII
+| MSCX
-                  characters.  It can contain any number from -128 to 127
+| ----
-                  (inclusive).
+| private Music-X format
-  unsigned char:  8 bits signed. Contains any number from 0 to 255 (inclusive).
+|-
-  short:          16 bits signed.  Contains any number from -32,768 to 32,767
+| MSMP
-                  (inclusive).
+| ----
-  unsigned short: 16 bits unsigned.  Contains any number from 0 to 65,535
+| temporarily reserved
-                  (inclusive).
+|-
-  long:           32 bits signed. Contains any number from -2,147,483,648
+| [[MTRX_IFF_Matrix_Data_Storage#MTRX|MTRX]]
-                  to 2,147,483,647 (inclusive).
+| IFF_TP
-  unsigned long:  32 bits unsigned. Contains any number from 0 to
+| Numerical data storage (MathVision - Seven Seas)
-,294,967,295 (inclusive).
+|-
-  extended:       80 bit IEEE Standard 754 floating point number (Standard
+| NSEQ
-                  Apple Numeric Environment [SANE] data type Extended)
+| ----
-  pstring:        Pascal-style string, a one-byte count followed by text
+| Numerical sequence (Stockhausen GmbH)
-                  bytes.  The total number of bytes in this data type should
+|-
-                  be even.  A pad byte can be added to the end of the text to
+| [[OB3D_IFF_3-D_Object_Format|OB3D]]
-                  accomplish this.  This pad byte is not reflected in the
+| propos
-                  count.
+| Proposal for a standard 3D object format
-  ID:             32 bits, the concatenation of four printable ASCII characters
+|-
-                  in the range &quot; &quot; (space, 0x20) through &quot;~&quot; (tilde, 0x7E).
+| OCMP
-                  Leading spaces are not allowed in the ID but trailing spaces
+| [[IFF_Standard|IFF Standard]]
-                  are OK.  Control characters are forbidden.
+| EA IFF 85 reserved computer prop
+|-
+| OCPU
-Constants
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 reserved processor prop
-Decimal values are referred to as a string of digits, for example 123, 0, 100
+|-
-are all decimal numbers.  Hexadecimal values are preceded by a 0x - e.g., 0x0A,
+| OPGM
-x1, 0x64.
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 reserved program prop
-Data Organization
+|-
+| OSN
-All data is stored in Motorola 68000 format.  The bytes of multiple-byte
+| [[IFF_Standard|IFF Standard]]
-values are stored with the high-order bytes first.  Data is organized as
+| EA IFF 85 reserved serial num. prop
-follows:
+|-
+| [[PGTB_IFF_Program_Traceback#PGTB|PGTB]]
-6  5  4  3  2  1  0
+| IFF_TP
-              +-----------------------+
+| Program traceback (SAS Institute)
-        char: | msb              lsb  |
+|-
-              +-----------------------+
+| PICS
+| [[IFF_Standard|IFF Standard]]
-14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
+| EA IFF 85 reserved Macintosh picture
-              +-----------------------+-----------------------+
+|-
-        char: | msb    byte 0         |        byte 1     lsb |
+| PLBM
-              +-----------------------+-----------------------+
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 reserved obsolete name
-14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
+|-
-              +-----------------------+-----------------------+
+| [[PMBC_IFF_High-color_Image_Format|PMBC]]
-        char: | msb    byte 0         |        byte 1         |
+| propos
-              +-----------------------+-----------------------+
+| reserved for Black Belt Systems 91.12.01
-        char: |        byte 2         |        byte 3     lsb |
+|-
-              +-----------------------+-----------------------+
+| PREF
+| ----
-                Figure 1: IFF data storage formats
+| Reserved by the AmigaOS Development Team for user preferences data, currently private
+|-
-Referring to Audio IFF
+| PREF.AHIG
+| private
-The official name for this standard is Audio Interchange File Format.  If an
+| AHI Global preferences
-application program needs to present the name of this format to a user, such
+|-
-as in a &quot;Save As...&quot; dialog box, the name can be abbreviated to Audio IFF.
+| PREF.AHIU
-Referring to Audio IFF files by a four-letter abbreviation (i.e., &quot;AIFF&quot;) in
+| private
-user-level documentation or program-generated messages should be avoided.
+| AHI Unit preferences
+|-
+| PROP
-File Structure
+| [[IFF_Standard|IFF Standard]]
+| EA IFF 85 group identifier
-The &quot;`EA IFF 85' Standard for Interchange Format Files&quot; defines an overall
+|-
-structure for storing data in files.  Audio IFF conforms to those portions
+| [[PRSP_IFF_Perspective_Move|PRSP]]
-of &quot;EA IFF 85&quot; that are germane to Audio IFF.  For a more complete discussion
+| IFF_TP
-of &quot;EA IFF 85&quot;, please refer to the document &quot;`EAIFF 85', Standard for
+| DPaint IV perspective move form (EA)
-Interchange Format Files.&quot;
+|-
+| PTCH
-An &quot;EA IFF 85&quot; file is made up of a number of chunks of data.  Chunks are the
+| ----
-building blocks of &quot;EA IFF 85&quot; files.  A chunk consists of some header
+| Patch file format (SAS Institute)
-information followed by data:
+|-
+| PTXT
-                +--------------------+
+| ----
-                |       ckID         |\
+| temporarily reserved
-                +--------------------+ } header info
+|-
-                |      ckSize        |/
+| RGB4
-                +--------------------+
+| ----
-                |                    |
+| 4-bit RGB (format not available)
-                |                    |
+|-
-                |       data         |
+| [[RGBN_and_RGB8_IFF_Image_Data|RGBN and RGB8]]
-                |                    |
+| IFF_TP
-                |                    |
+| RGB image forms, Turbo Silver (Impulse)
-                +--------------------+
+|-
+| RGBX
-                Figure 2: IFF Chunk structure
+| ----
+| temporarily reserved
-A chunk can be represented using our C-like language in the following manner:
+|-
+| ROXN
-    typedef struct {
+| ----
-        ID              ckID;           /* chunk ID             */
+| private animation form
-        long            ckSize;         /* chunk Size           */
+|-
+| [[SAMP_IFF_Sampled_Sound#SAMP|SAMP]]
-        char            ckData[];       /* data                 */
+| IFF_TP
-        } Chunk;
+| Sampled sound format
+|-
-The ckID describes the format of the data portion of a chunk.  A program can
+| SC3D
-determine how to interpret the chunk data by examining ckID.
+| ----
+| private scene format (Sculpt-3D)
-The ckSize is the size of the data portion of the chunk, in bytes.  It does
+|-
-not include the 8 bytes used by ckID and ckSize.
+| SHAK
+| ----
-The ckData contains the data stored in the chunk.  The format of this data is
+| private Shakespeare format
-determined by ckID.  If the data is an odd number of bytes in length, a zero pad
+|-
-byte must be added at the end.  The pad byte is not included in ckSize.
+| SHO1
+| ----
-Note that an array with no size specification (e.g., char ckData[];) indicates a
+| reserved by Gary Bonham (private)
-variable-sized array in our C-like language.  This differs from standard C.
+|-
+| SHOW
-An Audio IFF file is a collection of a number of different types of chunks.
+| ----
-There is a Common Chunk which contains important parameters describing the
+| reserved by Gary Bonham (private)
-sampled sound, such as its length and sample rate.  There is a Sound Data
+|-
-Chunk which contains the actual audio samples.  There are several other
+| [[SMUS_IFF_Simple_Musical_Score|SMUS]]
-optional chunks which define markers, list instrument parameters, store
+| EA_IFF
-application-specific information, etc.  All of these chunks are described in
+| EA IFF 85 simple music score form
-detail in later sections of this document.
+|-
+| [[SPLT_IFF_File_Splitting#SPLT|SPLT]]
-The chunks in an Audio IFF file are grouped together in a container chunk.
+| IFF_TP
-&quot;EA IFF 85&quot; Standard for Interchange Format Files  defines a number of
+| ASDG's file SPLiTting system
-container chunks, but the one used by Audio IFF is called a FORM.  A FORM has
+|-
-the following format:
+| SSRE
+| ----
-    typedef struct {
+| reserved for Merging Technologies 92.05.04
-        ID      ckID;
+|-
-        long    ckSize;
+| SWRT
+| ----
-        ID      formType;
+| unregistered (???)
-        char    chunks[];
+|-
-        }
+| SYTH
+| ----
-The ckID is always 'FORM'.  This indicates that this is a FORM chunk.
+| SoundQuest Master Librarian MIDI System driver
+|-
-The ckSize contains the size of data portion of the 'FORM' chunk.  Note that
+| TCDE
-the data portion has been broken into two parts, formType and chunks[].
+| ----
+| reserved by Merging Technologies
-The formType field describes what's in the 'FORM' chunk.  For Audio IFF files,
+|-
-formType is always 'AIFF'.  This indicates that the chunks within the FORM
+| [[TDDD_IFF_3-D_Rendering_Data#TDDD|TDDD]]
-pertain to sampled sound.  A FORM chunk of formType 'AIFF' is called a FORM
+| IFF_TP
-AIFF.
+| 3D rendering data, Turbo Silver (Impulse)
+|-
-The chunks field are the chunks contained within the FORM.  These chunks are
+| TERM
-called local chunks.  A FORM AIFF along with its local chunks make up an
+| ----
-Audio IFF file.
+| unregistered (???)
+|-
-Here is an example of a simple Audio IFF file.  It consists of a file containing
+| [[TMUI_IFF_Project_File_Format#TMUI|TMUI]]
-single FORM AIFF which contains two local chunks, a Common Chunk and a Sound
+| IFF_TP
-Data Chunk.
+| Toolmaker IFF project file format (ToolMaker V1.19)
+|-
-                        __________________________
+| [[TREE_IFF_Tree_Data_Structure|TREE]]
-                       | FORM AIFF Chunk          |
+| IFF_TP
-                       |   ckID  = 'FORM'         |
+| Storage of arbitrary data structures as trees (or nested lists)
-                       |   formType = 'AIFF'      |
+|-
-                       |    __________________    |
+| [[TRKR_IFF_Tracker_Music_Module|TRKR]]
-                       |   | Common Chunk     |   |
+| propos
-                       |   |   ckID = 'COMM'  |   |
+| TRacKeR style music module format proposal
-                       |   |__________________|   |
+|-
-                       |    __________________    |
+| UNAM
-                       |   | Sound Data Chunk |   |
+| [[IFF_Standard|IFF Standard]]
-                       |   |   ckID = 'SSND'  |   |
+| EA IFF 85 reserved user name prop
-                       |   |__________________|   |
+|-
-                       |__________________________|
+| USCR
+| [[IFF_Standard|IFF Standard]]
-                      Figure 3: Simple Audio IFF File
+| EA IFF 85 reserved Uhuru score
+|-
-There are no restrictions on the ordering of local chunks within a FORM AIFF.
+| UVOX
+| [[IFF_Standard|IFF Standard]]
-A more detailed example of an Audio IFF file can be found in Appendix A.  Please
+| EA IFF 85 reserved Uhuru Mac voice
-refer to this example as often as necessary while reading the remainder of this
+|-
-document.
+| VDEO
+| ----
+| private Deluxe Video format
-Storage of AIFF on Apple and Other Platforms
+|-
+| [[WORD_IFF_Document_Storage#WORD|WORD]]
-On a Macintosh, the FORM AIFF, is stored in the data fork of an Audio IFF file.
+| IFF_TP
-The Macintosh file type of an Audio IFF file is 'AIFF'.  This is the same as
+| ProWrite document format (New Horizons)
-the formType of the FORM AIFF.  Macintosh applications should not store any
+|-
-information in Audio IFF file's resource fork, as this information may not be
+| WOWO
-preserved by all applications.  Applications can use the Application Specific
+| ----
-Chunk, defined later in this document, to store extra information specific to
+| unregistered (Wordworth)
-their application.
+|-
+| YAFA
-Audio IFF files may be identified in other Apple file systems as well.  On a
+| ----
-Macintosh under MFS or HFS, the FORM AIFF is stored in the data fork of a file
+| unregistered animation format (Wildfire)
-with file type &quot;AIFF.&quot;  This is the same as the formType of the FORM AIFF.
+|-
+| [[YUVN_IFF_YUV_Image_Data#YUVN|YUVN]]
-On an operating system such as MS-DOS or UNIX, where it is customary to use a
+| IFF_TP
-file name extension, it is recommended that Audio IFF file names use &quot;.AIF&quot;
+| For storage of Y:U:V image data (MacroSystems)
-for the extension.
+|}
-On an Apple II, FORM AIFF is stored in a file with file type $D8 and auxiliary
-type $0000.  Versions 1.2 and earlier of the Audio IFF standard used file type
-$CB and auxiliary type $0000.  This is incorrect; the assignment listed in
-this document is the correct assignment.
-On the Apple IIGS stereo data is stored with right data on even channels and
-left data on odd channels.  Some portions of AIFF do not follow this
-convention.  Even where it does follow the convention, AIFF usually uses
-channel two for right data instead of channel zero as most Apple IIGS
-standards do.  Be prepared to interpret data accordingly.
-Local Chunk Types
-The formats of the different local chunk types found within a FORM AIFF are
-described in the following sections, as are their ckIDs.
-There are two types of chunks:  required and optional.  The Common Chunk is
-required.  The Sound Data chunk is required if the sampled sound has a length
-greater than zero.  All other chunks are optional.  All applications that use
-FORM AIFF must be able to read the required chunks and can choose to
-selectively ignore the optional chunks.  A program that copies a FORM AIFF
-should copy all the chunks in the FORM AIFF, even those it chooses not to
-interpret.
-The Common Chunk
-The Common Chunk describes fundamental parameters of the sampled sound.
-    #define     CommonID        'COMM'  /* ckID for Common Chunk */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        short           numChannels;
-        unsigned long   numSampleFrames;
-        short           sampleSize;
-        extended        sampleRate;
-    } CommonChunk;
-The ckID is always 'COMM'.  The ckSize is the size of the data portion of the
-chunk, in bytes.  It does not include the 8 bytes used by ckID and ckSize.
-For the Common Chunk, ckSize is always 18.
-The numChannels field contains the number of audio channels for the sound.
-A value of 1 means monophonic sound, 2 means stereo, and 4 means four channel
-sound, etc.  Any number of audio channels may be represented.  For
-multichannel sounds, single sample points from each channel are interleaved.
-A set of interleaved sample points is called a sample frame.
-The actual sound samples are stored in another chunk, the Sound Data Chunk,
-which will be described shortly.
-Single sample points from each channel are interleaved such that each
-sample frame is a sample point from the same moment in time for each channel
-available.
-The numSampleFrames field contains the number of sample frames.  This is not
-necessarily the same as the number of bytes nor the number of samplepoints in
-the Sound Data Chunk.  The total number of sample points in the file is
-numSampleFrames times numChannels.
-The sampleSize is the number of bits in each sample point.  It can be any
-number from 1 to 32.  The format of a sample point will be described in the
-next section.
-The sampleRate field is the sample rate at which the sound is to be played
-back in sample frames per second.
-One, and only one, Common Chunk is required in every FORM AIFF.
-Sound Data Chunk
-The Sound Data Chunk contains the actual sample frames.
-    #define     SoundDataID     'SSND'  /* ckID for Sound Data Chunk    */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        unsigned long   offset;
-        unsigned long   blockSize;
-        unsigned char   SoundData [];
-    }  SoundDataChunk;
-The ckID is always 'SSND'.  The ckSize is the size of the data portion of the
-chunk, in bytes.  It does not include the 8 bytes used by ckID and ckSize.
-The offset field determines where the first sample frame in the soundData
-starts.  The offset is in bytes.  Most applications won't use offset and
-should set it to zero.  Use for a non-zero offset is explained in the
-Block-Aligning Sound Data section below.
-The blockSize is used in conjunction with offset for block-aligning sound
-data.  It contains the size in bytes of the blocks that sound data is aligned
-to.  As with offset, most applications won't use blockSize and should set it
-to zero.  More information on blockSize is in the Block-Aligning Sound Data
-section below.
-The soundData field contains the sample frames that make up the sound.  The
-number of sample frames in the soundData is determined by the numSampleFrames
-field in the Common Chunk.  Sample points and sample frames are explained in
-detail in the next section.
-The Sound Data Chunk is required unless the numSampleFrames field in the
-Common Chunk is zero.  A maximum of one Sound Data Chunk may appear in a FORM
-AIFF.
-Sample Points and Sample Frames
-A large part of interpreting Audio IFF files revolves around the two concepts
-of sample points and sample frames.
-A sample point is a value representing a sample of a sound at a given point in
-time.  Each sample point is stored as a linear, 2's-complement value which may
-be from 1 to 32 bits wide, as determined by sampleSize in the Common Chunk.
-Sample points are stored in an integral number of contiguous bytes.  One- to
-eight-bit wide sample points are stored in one byte, 9- to 16-bit wide sample
-points are stored in two bytes, 17- to 24-bit wide sample points are stored
-in three bytes, and 25- to 32-bit wide sample points are stored in four bytes
-(most significant byte first).  When the width of a sample point is not a
-multiple of eight bits, the sample point data is left justified, with the
-remaining bits zeroed.  An example case is illustrated in Figure 4.  A 12-bit
-sample point, binary 101000010111, is stored left justified in two bytes.
-The remaining bits are set to zero.
-     ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___
-    |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
-    | 1   0   1   0   0   0   0   1 | 0   1   1   1   0   0   0   0 |
-    |___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
-     &lt;---------------------------------------------&gt; &lt;-------------&gt;
-bit sample point is left justified         rightmost
-bits are
-                                                        zero padded
-                      Figure 4: 12-Bit Sample Point
-For multichannel sounds, single sample points from each channel are
-interleaved.  A set of interleaved sample points is called a sample frame.
-Single sample points from each channel are interleaved such that each
-sample frame is a sample point from the same moment in time for each channel
-available.  This is illustrated in Figure 5 for the stereo (two channel) case.
-                   sample      sample              sample
-                   frame 0     frame 1             frame N
-                 _____ _____ _____ _____         _____ _____
-                | ch1 | ch2 | ch1 | ch2 | . . . | ch1 | ch2 |
-                |_____|_____|_____|_____|       |_____|_____|
-                             _____
-                            |     | = one sample point
-                            |_____|
-                Figure 5: Sample Frames for Multichannel Sound
-For monophonic sound, a sample frame is a single sample point.  For
-multichannel sounds, you should follow the conventions in Figure 6.
-                                       channel
-2          3          4          5          6
-             _________ _________ _________ _________ _________ _________
-            | left    | right   |         |         |         |         |
-  stereo    |         |         |         |         |         |         |
-            |_________|_________|_________|_________|_________|_________|
-            | left    | right   | center  |         |         |         |
-channel |         |         |         |         |         |         |
-            |_________|_________|_________|_________|_________|_________|
-            | front   | front   | rear    | rear    |         |         |
-  quad      | left    | right   | left    | right   |         |         |
-            |_________|_________|_________|_________|_________|_________|
-            | left    | center  | right   | surround|         |         |
-channel |         |         |         |         |         |         |
-            |_________|_________|_________|_________|_________|_________|
-            | left    | left    | center  | right   | right   |surround |
-channel |         | center  |         |         | center  |         |
-            |_________|_________|_________|_________|_________|_________|
-             Figure 6: Sample Frame Conventions for Multichannel Sound
-Sample frames are stored contiguously in order of increasing time.  The sample
-points within a sample frame are packed together; there are no unused bytes
-between them.  Likewise, the sample frames are packed together with no pad
-bytes.
-Block-Aligning Sound Data
-There may be some applications that, to ensure real time recording and
-playback of audio, wish to align sampled sound data with fixed-size blocks.
-This alignment can be accomplished with the offset and blockSize parameters of
-the Sound Data Chunk, as shown in Figure 7.
-        ____________ __________________________________ ____________
-       |\\ unused \\|          sample frames           |\\ unused \\|
-       |____________|__________________________________|____________|
-       &lt;-- offset --&gt;&lt;- numSampleFrames sample frames -&gt;
-    |   blockSize   |               |               |               |
-    |&lt;- bytes     -&gt;|               |               |               |
-    |_______________|_______________|_______________|_______________|
-       block N-1       block N         block N+1       block N+2
-                     Figure 7: Block-Aligned Sound Data
-In Figure 7, the first sample frame starts at the beginning of block N.  This
-is accomplished by skipping the first offset bytes of the soundData.  Note
-too, that the soundData bytes can extend beyond valid sample frames, allowing
-the soundData bytes to end on a block boundary as well.
-The blockSize specifies the size in bytes of the block to which you would
-align the sound data.  A blockSize of zero indicates that the sound data does
-not need to be block-aligned.  Applications that don't care about block
-alignment should set the blockSize and offset to zero when creating Audio IFF
-files.  Applications that write block-aligned sound data should set blockSize
-to the appropriate block size.  Applications that modify an existing Audio IFF
-file should try to preserve alignment of the sound data, although this is not
-required.  If an application does not preserve alignment, it should set the
-blockSize and offset to zero.  If an application needs to realign sound data
-to a different sized block, it should update blockSize and offset accordingly.
-The Marker Chunk
-The Marker Chunk contains markers that point to positions in the sound data.
-Markers can be used for whatever purposes an application desires.  The
-Instrument Chunk, defined later in this Note, uses markers to mark loop
-beginning and end points.
-Markers
-A marker has the following format.
-    typedef     short           MarkerId;
-    typedef     struct  {
-                MarkerID        id;
-                unsigned long   position;
-                pstring         markerName;
-    } Marker;
-The id is a number that uniquely identifies that marker within a FORM AIFF.
-The id can be any positive non-zero integer, as long as no other marker
-within the same FORM AIFF has the same id.
-The marker's position in the sound data is determined by the position field.
-Markers conceptually fall between two sample frames.  A marker that falls
-before the first sample frame in the sound data is at position zero, while a
-marker that falls between the first and second sample frame in the sound data
-is at position 1.  Note that the units for position  are sample frames, not
-bytes nor sample points.
-                              Sample Frames
-             ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___
-            |   |   |   |   |   |   |   |   |   |   |   |   |
-            |___|___|___|___|___|___|___|___|___|___|___|___|
-            ^                   ^                           ^
-        position 0          position 5                  position 12
-                 Figure 8: Sample Frame Marker Positions
-The markerName field is a Pascal-style text string containing the name of the
-mark.
-Note: Some &quot;EA IFF 85&quot; files store strings a C-strings (text bytes followed by
-a null terminating character) instead of Pascal-style strings.  Audio IFF uses
-pstrings because they are more efficiently skipped over when scanning through
-chunks.  Using pstrings, a program can skip over a string by adding the string
-count to the address of the first character.  C strings require that each
-character in the string be examined for the null terminator.
-Marker Chunk Format
-The format for the data within a Marker Chunk is shown below.
-    #define     MarkerID        'MARK'  /* ckID for Marker Chunk */
-    typedef  struct {
-        ID                              ckID;
-        long                            ckSize;
-        unsigned short          numMarkers;
-        Marker                  Markers [];
-    } MarkerChunk;
-The ckID is always 'MARK'.  The ckSize is the size of the data portion of the
-chunk in bytes.  It does not include the 8 bytes used by ckID and ckSize.
-The numMarkers field is the number of markers in the Marker Chunk.  If
-numMarkers is non-zero, it is followed by the markers themselves.  Because
-all fields in a marker are an even number of bytes, the length of any marker
-will always be even.  Thus, markers are packed together with no unused bytes
-between them.  The markers need not be ordered in any particular manner.
-The Marker Chunk is optional.  No more than one Marker Chunk can appear in a
-FORM AIFF.
-The Instrument Chunk
-The Instrument Chunk defines basic parameters that an instrument, such as a
-sample, could use to play the sound data.
-Looping
-Sound data can be looped, allowing a portion of the sound to be repeated in
-order to lengthen the sound.  The structure below describes a loop.
-    typedef struct {
-        short   PlayMode;
-        MarkerId beginLoop;
-        MarkerId endLoop;
-    } Loop;
-A loop is marked with two points, a begin position and an end position.  There
-are two ways to play a loop, forward looping and forward/backward looping.
-In the case of forward looping, playback begins at the beginning of the sound,
-continues past the begin position and continues to the end position, at which
-point playback starts again at the begin position.  The segment between the
-begin and end positions, called the loop segment, is played repeatedly until
-interrupted by a user action, such as the release of a key on a sampling
-instrument.
-                   ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___
-    sample frames |   |   |   |&lt;--- loop segment ----&gt;|   |   |   |
-                  |___|___|___|___|___|___|___|___|___|___|___|___|
-                              ^                       ^
-                        begin position           end position
-                        Figure 9: Sample Frame Looping
-With forward/backward looping, the loop segment is first played from the begin
-position to the end position, and then played backwards from the end position
-to the begin position.  This flip-flop pattern is repeated over and over again
-until interrupted.
-The playMode specifies which type of looping is to be performed:
-        #define NoLooping               0
-        #define ForwardLooping          1
-        #define ForwardBackwardLooping  2
-If NoLooping is specified, then the loop points are ignored during playback.
-The beginLoop is a marker id that marks the begin position of the loop segment.
-The endLoop marks the end position of a loop.  The begin position must be
-less than the end position.  If this is not the case, then the loop segment
-has zero or negative length and no looping takes place.
-The Instrument Chunk Format
-The format of the data within an Instrument Chunk is described below.
-    #define             InstrumentID    'INST'  /*ckID for Instruments Chunk */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        char            baseNote;
-        char            detune;
-        char            lowNote;
-        char            highNote;
-        char            lowvelocity;
-        char            highvelocity;
-        short           gain;
-        Loop            sustainLoop;
-        Loop            releaseLoop;
-    } InstrumentChunk;
-The ckID is always 'INST'.  ckSize is the size of the data portion of the
-chunk, in bytes.  For the Instrument Chunk, ckSize is always 20.
-The baseNote is the note at which the instrument plays back the sound data
-without pitch modification.  Units are MIDI (MIDI is an acronym for Musical
-Instrument Digital Interface) note numbers, and are in the range 0 through
-.  Middle C is 60.
-The detune field determines how much the instrument should alter the pitch of
-the sound when it is played back.  Units are in cents (1/100 of a semitone)
-and range from -50 to +50.  Negative numbers mean that the pitch of the sound
-should be lowered, while positive numbers mean that it should be raised.
-The lowNote and highNote fields specify the suggested range on a keyboard for
-playback of the sound data.  The sound data should be played if the instrument
-is requested to play a note between the low and high, inclusive.  The base
-note does not have to be within this range.  Units for lowNote and highNote
-are MIDI note values.
-The lowVelocity and highVelocity fields specify the suggested range of
-velocities for playback of the sound data.  The sound data should be played
-if the note-on velocity is between low and high velocity, inclusive.  Units
-are MIDI velocity values, 1 (lowest velocity) through 127 (highest velocity).
-The gain is the amount by which to change the gain of the sound when it is
-played.  Units are decibels.  For example, 0db means no change, 6db means
-double the value of each sample point, while -6db means halve the value of
-each sample point.
-The sustainLoop field specifies a loop that is to be played when an instrument
-is sustaining a sound.
-The releaseLoop field specifies a loop that is to be played when an instrument
-is in the release phase of playing back a sound.  The release phase usually
-occurs after a key on an instrument is released.
-The Instrument Chunk is optional.  No more than one Instrument Chunk can
-appear in a FORM AIFF.
-ASIF Note:    The Apple IIGS Sampled Instrument Format also defines a
-              chunk with ID of &quot;INST,&quot; which is not the same as the Audio
-              IFF Instrument Chunk.  A good way to tell the two chunks
-              apart in generic IFF-style readers is by the ckSize fields.
-              The Audio IFF Instrument Chunk's ckSize field is always 20,
-              whereas the Apple IIGS Sampled Instrument Format Instrument
-              Chunk's ckSize field, for structural reasons, can never be
-.
-The MIDI Data Chunk
-The MIDI Data Chunk can be used to store MIDI data.  Please refer to Musical
-Instrument Digital Interface Specification 1.0, available from the
-International MIDI Association, for more details on MIDI.
-The primary purpose of this chunk is to store MIDI System Exclusive messages,
-although other types of MIDI data can be stored in the block as well.  As more
-instruments come to market, they will likely have parameters that have not
-been included in the Audio IFF specification.  The MIDI System Exclusive
-messages for these instruments may contain many parameters that are not
-included in the Instrument Chunk.  For example, a new sampling instrument may
-have more than the two loops defined in the Instrument Chunk.  These loops
-will likely be represented in the MIDI System Exclusive message for the new
-machine.  This MIDI System Exclusive message can be stored in the MIDI Data
-Chunk.
-    #define             MIDIDataID      'MIDI' /* ckID for MIDI Data Chunk */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        unsigned char   MIDIdata[];
-    } MIDIDataChunk;
-The ckID is always 'MIDI'.  ckSize of the data portion of the chunk, in bytes.
-It does not include the 8 bytes used by ckID and ckSize.
-The MIDIData field contains a stream of MIDI data.
-The MIDI Data Chunk is optional.  Any number of MIDI Data Chunks may exist in
-a FORM AIFF.  If MIDI System Exclusive messages for several instruments are to
-be stored in a FORM AIFF, it is better to use one MIDI Data Chunk per
-instrument than one big MIDI Data Chunk for all of the instruments.
-The Audio Recording Chunk
-The Audio Recording Chunk contains information pertinent to audio recording
-devices.
-    #define     AudioRecordingID 'AESD'         /* ckID for Audio Recording */
-                                                /*  Chunk.                 */
-    typedef struct {
-        ID                      ckID
-        long                    ckSize;
-        unsigned char   AESChannelStatusData[24];
-    } AudioRecordingChunk;
-The ckID is always 'AESD'. The ckSize is the size of the data portion of the
-chunk, in bytes For the Audio Recording Chunk, ckSize is always 24.
-The 24 bytes of AESCChannelStatusData are specified in the &quot;AES Recommended
-Practice for Digital Audio Engineering - Serial Transmission Format for Linearly
-Represented Digital Audio Data&quot;, transmission of digital audio between audio
-devices.  This information is duplicated in the Audio Recording Chunk for
-convenience.  Of general interest would be bits 2, 3, and 4 of byte 0, which
-describe recording emphasis.
-The Audio Recording Chunk is optional.  No more than one Audio Recording Chunk
-may appear in a FORM AIFF.
-The Application Specific Chunk
-The Application Specific Chunk can be used for any purposes whatsoever by
-developers and application authors.  For example, an application that edits
-sounds might want to use this chunk to store editor state parameters such as
-magnification levels, last cursor position, etc.
-    #define     ApplicationSpecificID 'APPL' /* ckID for Application */
-                                             /*  Specific Chunk.     */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        OSType          applicationSignature;
-        char            data[];
-    } ApplicationSpecificChunk;
-The ckID is always 'APPL'.  The ckSize is the size of the data portion of the
-chunk, in bytes.  It does not include the 8 bytes used by ckID and ckSize.
-The applicationSignature identifies a particular application.  For Macintosh
-applications, this will be the application's four character signature.
-The OSType field is used by applications which run on platforms from Apple
-Computer, Inc.  For the Apple II, the OStype field should be set to 'pdos'.
-For the Macintosh, this field should be set to the four character signature
-as registered with Apple Technical Support.
-The data field is the data specific to the application.
-The Application Specific Chunk is optional.  Any number of Application
-Specific Chunks may exist in a single FORM AIFF.
-The Comments Chunk
-The Comments Chunk is used to store comments in the FORM AIFF.  &quot;EA IFF 85&quot;
-has an Annotation Chunk (used in ASIF) that can be used for comments, but the
-Comments Chunk has two features not found in the &quot;EA IFF 85&quot; chunk.  They are
-a time-stamp for the comment and a link to a marker.
-Comment
-A comment consists of a time stamp, marker id, and a text count followed by
-text.
-    typedef struct {
-        unsigned long   timeStamp;
-        MarkerID        marker;
-        unsigned short  count;
-        char            text;
-    } Comment;
-The timeStamp indicates when the comment was created.  On the Amiga, units
-are the number of seconds since January 1, 1978.  On the Macintosh, units are
-the number of seconds since January 1, 1904.
-A comment can be linked to a marker.  This allows applications to store long
-descriptions of markers as a comment.  If the comment is referring to a marker,
-then the marker field is the ID of that marker.  Otherwise, marker is zero,
-indicating that this comment is not linked to a marker.
-The count is the length of the text that makes up the comment.  This is a 16-bit
-quantity, allowing much longer comments than would be available with a pstring.
-The text field contains the comment itself.
-The Comments Chunk is optional.  No more than one Comments Chunk may appear in
-a single FORM AIFF.
-Comments Chunk Format
-    #define     CommentID       'COMT'  /* ckID for Comments Chunk  */
-    typedef struct {
-        ID              ckID;
-        long            ckSize;
-        unsigned short  numComments;
-        Comment         comments[];
-    }CommentsChunk;
-The ckID is always 'COMT'.  The ckSize is the size of the data portion of
-the chunk, in bytes.  It does not include the 8 bytes used by ckID and ckSize.
-The numComments field contains the number of comments in the Comments Chunk.
-This is followed by the comments themselves.  Comments are always even
-numbers of bytes in length, so there is no padding between comments in
-the Comments Chunk.
-The Comments Chunk is optional.  No more than one Comments Chunk may appear
-in a single FORM AIFF.
-The Text Chunks, Name, Author, Copyright, Annotation
-These four chunks are included in the definition of every &quot;EA IFF 85&quot; file.
-All are text chunks; their data portion consists solely of text.  Each of
-these chunks is optional.
-    #define     NameID 'NAME'   /* ckID for Name Chunk */
-    #define     NameID 'AUTH'   /* ckID for Author Chunk */
-    #define     NameID '(c) '   /* ckID for Copyright Chunk */
-    #define     NameID 'ANNO'   /* ckID for Annotation Chunk */
-    typedef struct {
-        ID      ckID;
-        long    ckSize;
-        char    text[];
-    }TextChunk;
-The ckID is either 'NAME', 'AUTH', '(c) ', or 'ANNO' depending on whether the
-chunk is a Name Chunk, Author Chunk, Copyright Chunk, or  Annotation Chunk,
-respectively.  For the Copyright Chunk, the 'c' is lowercase and there is a
-space (0x20) after the close parenthesis.
-The ckSize is the size of the data portion of the chunk, in this case the text.
-The text field contains pure ASCII characters.  it is not a pstring or a C
-string.  The number of characters in text is determined by ckSize.  The
-contents of text depend on the chunk, as described below:
-Name Chunk. The text contains the name of the sampled sound.  The Name Chunk
-is optional.  No more than one Name Chunk may exist within a FORM AIFF.
-Author Chunk. The text contains one or more author names.  An author in this
-case is the creator of a sampled sound.  The Author Chunk is optional.  No
-more than one Author Chunk may exist within a FORM AIFF.
-Copyright Chunk.  The Copyright Chunk contains a copyright notice for the
-sound.  The text field contains a date followed by the name of the copyright
-owner.  The chunk ID '(c) ' serves as the copyright character.  For example,
-a Copyright Chunk containing the text &quot;1991 Commodore-Amiga, Inc.&quot; means
-&quot;(c) 1991 Commodore-Amiga, Inc.&quot;  The Copyright Chunk is optional.  No more
-than one Copyright Chunk may exist within a FORM AIFF.
-Annotation Chunk.  The text contains a comment.  Use of this chunk is
-discouraged within a FORM AIFF.  The more powerful Comments Chunk should be
-used instead.  The Annotation Chunk is optional.  Many Annotation Chunks may
-exist within a FORM AIFF.
-Chunk Precedence
-Several of the local chunks for FORM AIFF may contain duplicate information.
-For example, the Instrument Chunk defines loop points and MIDI System
-Exclusive data in the MIDI Data Chunk may also define loop points.  What
-happens if these loop points are different?  How is an application supposed to
-loop the sound?  Such conflicts are resolved by defining a precedence for
-chunks.  This precedence is illustrated in Figure 10.
-                       Common Chunk           Highest Precedence
-                            |
-                     Sound Data Chunk
-                            |
-                       Marker Chunk
-                            |
-                     Instrument Chunk
-                            |
-                       Comment Chunk
-                            |
-                        Name Chunk
-                            |
-                       Author Chunk
-                            |
-                      Copyright Chunk
-                            |
-                      Annotation Chunk
-                            |
-                   Audio Recording Chunk
-                            |
-                      MIDI Data Chunk
-                            |
-                 Application Specific Chunk   Lowest Precedence
-                         Figure 10: Chunk Precedence
-The Common Chunk has the highest precedence, while the Application Specific
-Chunk has the lowest.  Information in the Common Chunk always takes precedence
-over conflicting information in any other chunk.  The Application Specific
-Chunk always loses in conflicts with other chunks.  By looking at the chunk
-hierarchy, for example, one sees that the loop points in the Instrument Chunk
-take precedence over conflicting loop points found in the MIDI Data Chunk.
-It is the responsibility of applications that write data into the lower
-precedence chunks to make sure that the higher precedence chunks are updated
-accordingly.
-Figure 11 illustrates an example of a FORM AIFF.  An Audio IFF file is simple
-a file containing a single FORM AIFF.  The FORM AIFF is stored in the data
-fork of Macintosh file systems that can handle resource forks.
-     _____________________________________________________________________
-    | FORM AIFF                                                           |
-    |                          _____________                              |
-    |                    ckID |_ 'FORM' ____|                             |
-    |                  ckSize |_ 176516 ____|                             |
-    |  _____________ formType |_ 'AIFF' ____| __________________________  |
-    | | Common           ckID |_ 'COMM' ____|                           | |
-    | | Chunk          ckSize |_ 18 ________|                           | |
-    | |           numChannels |_ 2 ___|_____                            | |
-    | |       numSampleFrames |_ 88200 _____|                           | |
-    | |            sampleSize |_ 16 __|_______________________________  | |
-    | |___________ sampleRate |_ 44100.00 ____________________________| | |
-    | | Marker           ckID |_ 'MARK' _____|                          | |
-    | | Chunk          ckSize |_ 34 _________|                          | |
-    | |            numMarkers |_ 2 ___|                                 | |
-    | |                    id |_ 1 ___|_______                          | |
-    | |              position |_ 44100 ___ ___|___ ___ ___ ___ ___ ___  | |
-    | |            markerName | 8 |'b'|'e'|'g'|' '|'l'|'o'|'o'|'p'| 0 | | |
-    | |                    id |_ 2 ___|_______                          | |
-    | |              position |_ 88200 _______|___ ___ ___ ___ ___ ___  | |
-    | |___________ markerName | 8 |'e'|'n'|'d'|' '|'l'|'o'|'o'|'p'| 0 | | |
-    | | Instrument       ckID |_ 'INST' ______|                         | |
-    | | Chunk          ckSize |_ 20 __________|                         | |
-    | |              baseNote | 60|                                     | |
-    | |                detune | -3|                                     | |
-    | |               lowNote | 57|                                     | |
-    | |              highNote | 63|                                     | |
-    | |           lowVelocity | 1 |                                     | |
-    | |          highVelocity |127|__                                   | |
-    | |                  gain |_ 6 __|                                  | |
-    | |  sustainLoop.playMode |_ 1 __|                                  | |
-    | | sustainLoop.beginLoop |_ 1 __|                                  | |
-    | |   sustainLoop.endLoop |_ 2 __|                                  | |
-    | |  releaseLoop.playMode |_ 0 __|                                  | |
-    | | releaseLoop.beginLoop |_ - __|                                  | |
-    | |__ releaseLoop.endLoop |_ - __|__________________________________| |
-    | | Sound            ckID |_ 'SSND' ______|                         | |
-    | | Data           ckSize |_ 176408 ______|                         | |
-    | | Chunk          offset |_ 0 ___________|                         | |
-    | |             blockSize |_ 0 ___________|        _______ _______  | |
-    | |             soundData |_ch 1 _|_ch 2 _| . . . |_ch 1 _|_ch 2 _| | |
-    | |                       first sample frame   88200th sample frame | |
-    | |_________________________________________________________________| |
-    |_____________________________________________________________________|
-                         Figure 11: Sample FORM AIFF
-Further Reference
-_____________________________________________________________________________
-    o    &quot;Inside Macintosh&quot;, Volume II, Apple Computer, Inc.
-    o    &quot;Apple Numerics Manual&quot;, Second Edition, Apple Computer, Inc.
-    o    &quot;File Type Note: File Type $D8, Auxiliary Type $0002, Apple IIGS
-          Sampled Instrument Format&quot;, Apple Computer, Inc.
-    o    &quot;Audio Interchange File Format v1.3&quot;,  APDA
-    o    &quot;AES Recommended Practice for Digital Audio Engineering--Serial
-         Transmission Format for Linearly Represented Digital Audio Data&quot;,
-         Audio Engineering Society, 60 East 42nd Street, New York, NY 10165
-    o    &quot;MIDI:  Musical Instrument Digital Interface, Specification 1.0&quot;, the
-         International MIDI Association.
-    o    &quot;`EA IFF 85' Standard for Interchange Format Files&quot;, Electronic Arts
-    o    &quot;`8SVX' IFF 8-bit Sampled Voice&quot;, Electronic Arts</pre>
-=== Animated bitmap ===
-<pre>Animated bitmap form (Framer, Deluxe Video)
-TITLE:  Form ANBM (animated bitmap form used by Framer, Deluxe Video)
-(note from the author)
-   The format was designed for simplicity at a time when the IFF
-standard was very new and strange to us all.  It was not designed
-to be a general purpose animation format.  It was intended to be
-a private format for use by DVideo, with the hope that a more
-powerful format would emerge as the Amiga became more popular.
-   I hope you will publish this format so that other formats will
-not inadvertantly conflict with it.
-PURPOSE:  To define simple animated bitmaps for use in DeluxeVideo.
-   In Deluxe Video objects appear and move in the foreground
-with a picture in the background.  Objects are &quot;small&quot; bitmaps
-usually saved as brushes from DeluxePaint and pictures are large
-full screen bitmaps saved as files from DeluxePaint.
-   Two new chunk headers are defined: ANBM and FSQN.
-   An animated bitmap (ANBM) is a series of bitmaps of the same
-size and depth.  Each bitmap in the series is called a frame and
-is labeled by a character, 'a b c ...' in the order they
-appear in the file.
-   The frame sequence chunk (FSQN) specifies the playback
-sequence of the individual bitmaps to achieve animation.
-FSQN_CYCLE and FSQN_TOFRO specify two algorithmic sequences.  If
-neither of these bits is set, an arbitrary sequence can be used
-instead.
-    ANBM         - identifies this file as an animated bitmap
-    .FSQN        - playback sequence information
-    .LIST ILBM   - LIST allows following ILBMs to share properties
-    ..PROP ILBM  - properties follow
-    ...BMHD      - bitmap header defines common size and depth
-    ...CMAP      - colormap defines common colors
-    ..FORM ILBM  - first frame follows
-    ..BODY       - the first frame
-       .         - FORM ILBM and BODY for each remaining frame
-       .
-       .
-Chunk Description:
-   The ANBM chunk identifes this file as an animated bitmap
-Chunk Spec:
-   #define ANBM    MakeID('A','N','B','M')
-Disk record:
-   none
-Chunk Description:
-   The FSQN chunk specifies the frame playback sequence
-Chunk Spec:
-   #define FSQN    MakeID('F','S','Q','N')
-   /* Flags */
-   #define FSQN_CYCLE  0x0001  /* Ignore sequence, cycle a,b,..y,z,a,b,.. */
-   #define FSQN_TOFRO  0x0002  /* Ignore sequence, cycle a,b,..y,z,y,..a,b, */
-   /* Disk record */
-   typedef struct {
-       WORD numframes;      /* Number of frames in the sequence */
-       LONG dt;             /* Nominal time between frames in jiffies */
-       WORDBITS flags;      /* Bits modify behavior of the animation */
-       UBYTE sequence[80];  /* string of 'a'..'z' specifying sequence */
-       } FrameSeqn;
-Supporting Software:
-   DeluxeVideo by Mike Posehn and Tom Case for Electronic Arts
-Thanks,
-   Mike Posehn</pre>
-=== ANIM brush ===
-<pre>              Dpaint Anim Brush IFF Format
-        From a description by the author of DPaint,
-                      Dan Silva
-                    Electronic Arts
-The &quot;Anim Brushes&quot; of DPaint III are saved on disk in the IFF &quot;ANIM&quot;
-format.  Basically, an ANIM Form consists of an initial ILBM
-which is the first frame of the animation, and any number of
-subsequent &quot;ILBM&quot;S (which aren't really ILBM's) each of which
-contains an ANHD animation header chunk and a DLTA chunk
-comprised of the encoded difference between a frame and a previous one.
-To use ANIM terminology (for a description of the ANIM format,
-see the IFF Anim Spec, by Gary Bonham). Anim Brushes use a &quot;type
-&quot; encoding, which is a vertical, byte-oriented delta encoding
-(based on Jim Kent's RIFF).  The deltas have an interleave of 1,
-meaning deltas are computed between adjacent frames, rather than
-between frames 2 apart, which is the usual ANIM custom for the
-purpose of fast hardware page-flipping.  Also, the deltas use
-Exclusive Or to allow reversable play.
-However, to my knowledge, all the existing Anim players in the Amiga
-world will only play type 5 &quot;Anim&quot;s which have an interleave of 0 (i.e. 2)
-and which use a Store operation rather than Exclusive Or, so no existing
-programs will read Anim Brushes anyway.  The job of modifying existing
-Anim readers to read Anim Brushes should be simplified, however.
-Here is an outline of the structure of the IFF Form output by
-DPaint III as an &quot;Anim Brush&quot;. The IFF Reader should of course be
-flexible enough to tolerate variation in what chunks actually
-appear in the initial ILBM.
-                  FORM ANIM
-                      . FORM ILBM         first frame
-                      . . BMHD
-                      . . CMAP
-                      . . DPPS
-                      . . GRAB
-                      . . CRNG
-                      . . CRNG
-                      . . CRNG
-                      . . CRNG
-                      . . CRNG
-                      . . CRNG
-                      . . DPAN     my own little chunk.
-                      . . CAMG
-                      . . BODY
-                      . FORM ILBM         frame 2
-                      . . ANHD                animation header chunk
-                      . . DLTA                delta mode data
-                      . FORM ILBM         frame 3
-                      . . ANHD                animation header chunk
-                      . . DLTA                delta mode data
-                      . FORM ILBM         frame 4
-                      . . ANHD                animation header chunk
-                      . . DLTA                delta mode data
-       ...
-                   . FORM ILBM         frame N
-                      . . ANHD                animation header chunk
-                      . . DLTA                delta mode data
---- Here is the format of the DPAN chunk:
-typedef struct {
- UWORD version;   /* current version=4 */
- UWORD nframes;   /* number of frames in the animation.*/
- ULONG flags;   /* Not used */
- } DPAnimChunk;
-  The version number was necessary during development. At present
-all I look at is &quot;nframes&quot;.
---- Here is the ANHD chunk format:
-typedef struct {
- UBYTE operation;  /* =0  set directly
-       =1  XOR ILBM mode,
-       =2 Long Delta mode,
-       =3 Short Delta mode
-       =4 Generalize short/long Delta mode,
-       =5 Byte Vertical Delta (riff)
-       =74 (Eric Grahams compression mode)
-   */
- UBYTE mask;      /* XOR ILBM only: plane mask where data is*/
- UWORD w,h;
- WORD x,y;
- ULONG abstime;
- ULONG reltime;
- UBYTE interleave; /* 0 defaults to 2 */
- UBYTE pad0;   /* not used */
- ULONG bits;   /* meaning of bits:
-     bit#    =0         =1
-short data      long data
-store         XOR
-separate info       one info for
-      for each plane     for all planes
-not RLC    RLC (run length encoded)
-horizontal   vertical
-short info offsets long info offsets
-   -------------------------*/
- UBYTE pad[16];
- } AnimHdr;
-for Anim Brushes, I set:
- animHdr.operation = 5;  /* RIFF encoding */
- animHdr.interleave = 1;
- animHdr.w = curAnimBr.bmob.pict.box.w;
- animHdr.h = curAnimBr.bmob.pict.box.h;
- animHdr.reltime = 1;
- animHdr.abstime = 0;
- animHdr.bits = 4; /* indicating XOR */
--- everything else is set to 0.
-NOTE: the &quot;bits&quot; field was actually intended ( by the original
-creator of the ANIM format, Gary Bonham of SPARTA, Inc.) for use
-with only with compression method 4. I am using bit 2 of the bits
-field to indicate the Exclusive OR operation in the context of
-method 5, which seems like a reasonable generalization.
-For an Anim Brush with 10 frames, there will be an initial frame
-followed by 10 Delta's (i.e ILBMS containing ANHD and DLTA
-chunks).  Applying the first Delta to the initial frame generates
-the second frame, applying the second Delta to the second frame
-generates the third frame, etc.  Applying the last Delta thus
-brings back the first frame.
-The DLTA chunk begins with 16 LONG plane offets, of which DPaint
-only uses the first 6 (at most).  These plane offsets are either
-the offset (in bytes ) from the beginning of the DLTA chunk to
-the data for the corresponding plane, or Zero, if there was no
-change in that plane.  Thus the first plane offset is either 0 or
-.
-(The following description of the method is based on Gary Bonham's
-rewording of Jim Kent's RIFF documentation.)
-  Compression/decompression is performed on a plane-by-plane
-  basis.
-  Each byte-column of the bitplane is compressed separately.  A
-x200 bitplane would have 40 columns of 200 bytes each.  In
-  general, the bitplanes are always an even number of bytes wide,
-  so for instance a 17x20 bitplane would have 4 columns of 20
-  bytes each.
-  Each column starts with an op-count followed by a number of
-  ops.  If the op-count is zero, that's ok, it just means there's
-  no change in this column from the last frame.  The ops are of
-  three kinds, and followed by a varying amount of data depending
-  on which kind:
-. SKIP - this is a byte with the hi bit clear that   says
-        how many rows to move the &quot;dest&quot; pointer forward, ie to
-        skip. It is non-zero.
-. DUMP - this is a byte with the hi bit set.  The hi bit is
-        masked off and the remainder is a count of the number of
-        bytes of data to XOR directly.  It is followed by the
-        bytes to copy.
-. RUN - this is a 0 byte followed by a count byte, followed
-        by a byte value to repeat &quot;count&quot; times, XOR'ing it into
-        the destination.
-  Bear in mind that the data is compressed vertically rather than
-  horizontally, so to get to the next byte in the destination  you
-  add the number of bytes per row instead of one.
-The Format of DLTA chunks is as described in section 2.2.2
-of the Anim Spec. The encoding for type 5 is described in section
-.2.3 of the Anim Spec.  </pre>
-=== Cel animation ===
-<pre>                              A N I M
-                  An IFF Format For CEL Animations
-                    Revision date:  4 May 1988
-                     prepared by:
-                          SPARTA Inc.
-de la Carlota
-                          Laguna Hills, Calif 92653
-                          (714) 768-8161
-                          contact: Gary Bonham
-                     also by:
-                          Aegis Development Co.
-Pico Blvd.
-                          Santa Monica, Calif 90405
-) 392-9972
-.0 Introduction
-   The ANIM IFF format was developed at Sparta originally for the
-   production of animated video sequences on the Amiga computer.  The
-   intent was to be able to store, and play back, sequences of frames
-   and to minimize both the storage space on disk (through compression)
-   and playback time (through efficient de-compression algorithms).
-   It was desired to maintain maximum compatibility with existing
-   IFF formats and to be able to display the initial frame as a normal
-   still IFF picture.
-   Several compression schemes have been introduced in the ANIM format.
-   Most of these are strictly of historical interest as the only one
-   currently being placed in new code is the vertical run length
-   encoded byte encoding developed by Jim Kent.
-.1 ANIM Format Overview
-      The general philosophy of ANIMs is to present the initial frame
-      as a normal, run-length-encoded, IFF picture.  Subsequent
-      frames are then described by listing only their differences
-      from a previous frame.  Normally, the &quot;previous&quot; frame is two
-      frames back as that is the frame remaining in the hidden
-      screen buffer when double-buffering is used.  To better
-      understand this, suppose one has two screens, called A and B,
-      and the ability to instantly switch the display from one to
-      the other.  The normal playback mode is to load the initial
-      frame into A and duplicate it into B.  Then frame A is displayed
-      on the screen.  Then the differences for frame 2 are used to
-      alter screen B and it is displayed.  Then the differences for
-      frame 3 are used to alter screen A and it is displayed, and so
-      on.  Note that frame 2 is stored as differences from frame 1,
-      but all other frames are stored as differences from two frames
-      back.
-      ANIM is an IFF FORM and its basic format is as follows (this
-      assumes the reader has a basic understanding of IFF format
-      files):
-                      FORM ANIM
-                      . FORM ILBM         first frame
-                      . . BMHD                normal type IFF data
-                      . . ANHD                optional animation header
-                                              chunk for timing of 1st frame.
-                      . . CMAP
-                      . . BODY
-                      . FORM ILBM         frame 2
-                      . . ANHD                animation header chunk
-                      . . DLTA                delta mode data
-                      . FORM ILBM         frame 3
-                      . . ANHD
-                      . . DLTA
-                           ...
-      The initial FORM ILBM can contain all the normal ILBM chunks,
-      such as CRNG, etc.  The BODY will normally be a standard
-      run-length-encoded data chunk (but may be any other legal
-      compression mode as indicated by the BMHD).  If desired, an ANHD
-      chunk can appear here to provide timing data for the first
-      frame.  If it is here, the operation field should be =0.
-      The subsequent FORMs ILBM contain an ANHD, instead of a BMHD,
-      which duplicates some of BMHD and has additional parameters
-      pertaining to the animation frame.  The DLTA chunk contains
-      the data for the delta compression modes.  If
-      the older XOR compression mode is used, then a BODY chunk
-      will be here.  In addition, other chunks may be placed in each
-      of these as deemed necessary (and as code is placed in player
-      programs to utilize them).  A good example would be CMAP chunks
-      to alter the color palette.  A basic assumption in ANIMs is
-      that the size of the bitmap, and the display mode (e.g. HAM)
-      will not change through the animation.  Take care when playing
-      an ANIM that if a CMAP occurs with a frame, then the change must
-      be applied to both buffers.
-      Note that the DLTA chunks are not interleaved bitmap representations,
-      thus the use of the ILBM form is inappropriate for these frames.
-      However, this inconsistency was not noted until there were a number
-      of commercial products either released or close to release which
-      generated/played this format.  Therefore, this is probably an
-      inconsistency which will have to stay with us.
-.2 Recording ANIMs
-      To record an ANIM will require three bitmaps - one for
-      creation of the next frame, and two more for a &quot;history&quot; of the
-      previous two frames for performing the compression calculations
-      (e.g. the delta mode calculations).
-      There are five frame-to-frame compression methods currently
-      defined.  The first three are mainly for historical interest.
-      The product Aegis VideoScape 3D utilizes the third method in
-      version 1.0, but switched to method 5 on 2.0.  This is
-      the only instance known of a commercial product generating
-      ANIMs of any of the first three methods.  The fourth method
-      is a general short or long word compression scheme which has
-      several options including whether the compression is horizontal
-      or vertical, and whether or not it is XOR format.  This offers
-      a choice to the user for the optimization of file size and/or
-      playback speed.  The fifth method is the byte vertical run length
-      encoding as designed by Jim Kent.  Do not confuse
-      this with Jim's RIFF file format which is different than ANIM.
-      Here we utilized his compression/decompression routines within the
-      ANIM file structure.
-      The following paragraphs give a general outline of each of the
-      methods of compression currently included in this spec.
-.2.1 XOR mode
-         This mode is the original and is included here for historical
-         interest.  In general, the delta modes are far superior.
-         The creation of XOR mode is quite simple.  One simply
-         performs an exclusive-or (XOR) between all corresponding
-         bytes of the new frame and two frames back.  This results
-         in a new bitmap with 0 bits wherever the two frames were
-         identical, and 1 bits where they are different.  Then this
-         new bitmap is saved using run-length-encoding.  A major
-         obstacle of this mode is in the time consumed in performing
-         the XOR upon reconstructing the image.
-.2.2 Long Delta mode
-         This mode stores the actual new frame long-words which are
-         different, along with the offset in the bitmap.  The
-         exact format is shown and discussed in section 2 below.
-         Each plane is handled separately, with no data being saved
-         if no changes take place in a given plane.  Strings of
-or more long-words in a row which change can be run
-         together so offsets do not have to be saved for each one.
-         Constructing this data chunk usually consists of having
-         a buffer to hold the data, and calculating the data as
-         one compares the new frame, long-word by long-word, with
-         two frames back.
-.2.3 Short Delta mode
-         This mode is identical to the Long Delta mode except that
-         short-words are saved instead of long-words.  In most
-         instances, this mode results in a smaller DLTA chunk.
-         The Long Delta mode is mainly of interest in improving
-         the playback speed when used on a 32-bit 68020 Turbo Amiga.
-.2.4 General Delta mode
-         The above two delta compression modes were hastily put together.
-         This mode was an attempt to provide a well-thought-out delta
-         compression scheme.  Options provide for both short and long
-         word compression, either vertical or horizontal compression,
-         XOR mode (which permits reverse playback), etc.  About the time
-         this was being finalized, the fifth mode, below, was developed
-         by Jim Kent.  In practice the short-vertical-run-length-encoded
-         deltas in this mode play back faster than the fifth mode (which
-         is in essence a byte-vertical-run-length-encoded delta mode) but
-         does not compress as well - especially for very noisy data such
-         as digitized images.  In most cases, playback speed not being
-         terrifically slower, the better compression (sometimes 2x) is
-         preferable due to limited storage media in most machines.
-         Details on this method are contained in section 2.2.2 below.
-.2.5 Byte Vertical Compression
-         This method does not offer the many options that method 4 offers,
-         but is very successful at producing decent compression even for
-         very noisy data such as digitized images.  The method was devised
-         by Jim Kent and is utilized in his RIFF file format which is
-         different than the ANIM format.  The description of this method
-         in this document is taken from Jim's writings.  Further, he has
-         released both compression and decompression code to public domain.
-         Details on this method are contained in section 2.2.3 below.
-.3 Playing ANIMs
-      Playback of ANIMs will usually require two buffers, as mentioned
-      above, and double-buffering between them.  The frame data from
-      the ANIM file is used to modify the hidden frame to the next
-      frame to be shown.  When using the XOR mode, the usual run-
-      length-decoding routine can be easily modified to do the
-      exclusive-or operation required.  Note that runs of zero bytes,
-      which will be very common, can be ignored, as an exclusive or
-      of any byte value to a byte of zero will not alter the original
-      byte value.
-      The general procedure, for all compression techniques, is to first
-      decode the initial ILBM picture into the hidden buffer and double-
-      buffer it into view.  Then this picture is copied to the other (now
-      hidden) buffer.  At this point each frame is displayed with the
-      same procedure.  The next frame is formed in the hidden buffer by
-      applying the DLTA data (or the XOR data from the BODY chunk in the
-      case of the first XOR method) and the new frame is double-buffered
-      into view.  This process continues to the end of the file.
-      A master colormap should be kept for the entire ANIM which would
-      be initially set from the CMAP chunk in the initial ILBM.  This
-      colormap should be used for each frame.  If a CMAP chunk appears
-      in one of the frames, then this master colormap is updated and the
-      new colormap applies to all frames until the occurrance of another
-      CMAP chunk.
-      Looping ANIMs may be constructed by simply making the last two frames
-      identical to the first two.  Since the first two frames are special
-      cases (the first being a normal ILBM and the second being a delta from
-      the first) one can continually loop the anim by repeating from frame
-      three.  In this case the delta for creating frame three will modify
-      the next to the last frame which is in the hidden buffer (which is
-      identical to the first frame), and the delta for creating frame four
-      will modify the last frame which is identical to the second frame.
-      Multi-File ANIMs are also supported so long as the first two frames
-      of a subsequent file are identical to the last two frames of the
-      preceeding file.  Upon reading subsequent files, the ILBMs for the
-      first two frames are simply ignored, and the remaining frames are
-      simply appended to the preceeding frames.  This permits splitting
-      ANIMs across multiple floppies and also permits playing each section
-      independently and/or editing it independent of the rest of the ANIM.
-      Timing of ANIM playback is easily achieved using the vertical blank
-      interrupt of the Amiga.  There is an example of setting up such
-      a timer in the ROM Kernel Manual.  Be sure to remember the timer
-      value when a frame is flipped up, so the next frame can be flipped
-      up relative to that time.  This will make the playback independent
-      of how long it takes to decompress a frame (so long as there is enough
-      time between frames to accomplish this decompression).
-.0 Chunk Formats
-.1 ANHD Chunk
-      The ANHD chunk consists of the following data structure:
-           UBYTE operation  The compression method:
-                            =0 set directly (normal ILBM BODY),
-                            =1 XOR ILBM mode,
-                            =2 Long Delta mode,
-                            =3 Short Delta mode,
-                            =4 Generalized short/long Delta mode,
-                            =5 Byte Vertical Delta mode
-                            =6 Stereo op 5 (third party)
-                            =74 (ascii 'J') reserved for Eric Graham's
-                               compression technique (details to be
-                               released later).
-           UBYTE mask      (XOR mode only - plane mask where each
-                            bit is set =1 if there is data and =0
-                            if not.)
-           UWORD w,h       (XOR mode only - width and height of the
-                            area represented by the BODY to eliminate
-                            unnecessary un-changed data)
-           WORD  x,y       (XOR mode only - position of rectangular
-                            area representd by the BODY)
-           ULONG abstime   (currently unused - timing for a frame
-                            relative to the time the first frame
-                            was displayed - in jiffies (1/60 sec))
-           ULONG reltime   (timing for frame relative to time
-                            previous frame was displayed - in
-                            jiffies (1/60 sec))
-           UBYTE interleave (unused so far - indicates how may frames
-                             back this data is to modify.  =0 defaults
-                             to indicate two frames back (for double
-                             buffering). =n indicates n frames back.
-                             The main intent here is to allow values
-                             of =1 for special applications where
-                             frame data would modify the immediately
-                             previous frame)
-           UBYTE pad0        Pad byte, not used at present.
-           ULONG bits        32 option bits used by options=4 and 5.
-                             At present only 6 are identified, but the
-                             rest are set =0 so they can be used to
-                             implement future ideas.  These are defined
-                             for option 4 only at this point.  It is
-                             recommended that all bits be set =0 for
-                             option 5 and that any bit settings
-                             used in the future (such as for XOR mode)
-                             be compatible with the option 4
-                             bit settings.   Player code should check
-                             undefined bits in options 4 and 5 to assure
-                             they are zero.
-                             The six bits for current use are:
-                             bit #              set =0               set =1
-                             ===============================================
-short data           long data
-set                  XOR
-separate info        one info list
-                                           for each plane       for all planes
-not RLC        RLC (run length coded)
-horizontal           vertical
-short info offsets   long info offsets
-           UBYTE pad[16]     This is a pad for future use for future
-                             compression modes.
-.2 DLTA Chunk
-      This chunk is the basic data chunk used to hold delta compression
-      data.  The format of the data will be dependent upon the exact
-      compression format selected.  At present there are two basic
-      formats for the overall structure of this chunk.
-.2.1 Format for methods 2 &amp; 3
-         This chunk is a basic data chunk used to hold the delta
-         compression data.  The minimum size of this chunk is 32 bytes
-         as the first 8 long-words are byte pointers into the chunk for
-         the data for each of up to 8 bitplanes.  The pointer for the
-         plane data starting immediately following these 8 pointers will
-         have a value of 32 as the data starts in the 33-rd byte of the
-         chunk (index value of 32 due to zero-base indexing).
-         The data for a given plane consists of groups of data words.  In
-         Long Delta mode, these groups consist of both short and long
-         words - short words for offsets and numbers, and long words for
-         the actual data.  In Short Delta mode, the groups are identical
-         except data words are also shorts so all data is short words.
-         Each group consists of a starting word which is an offset.  If
-         the offset is positive then it indicates the increment in long
-         or short words (whichever is appropriate) through the bitplane.
-         In other words, if you were reconstructing the plane, you would
-         start a pointer (to shorts or longs depending on the mode) to
-         point to the first word of the bitplane.  Then the offset would
-         be added to it and the following data word would be placed at
-         that position.  Then the next offset would be added to the
-         pointer and the following data word would be placed at that
-         position.  And so on...  The data terminates with an offset
-         equal to 0xFFFF.
-         A second interpretation is given if the offset is negative.  In
-         that case, the absolute value is the offset+2.  Then the
-         following short-word indicates the number of data words that
-         follow.  Following that is the indicated number of contiguous
-         data words (longs or shorts depending on mode) which are to
-         be placed in contiguous locations of the bitplane.
-         If there are no changed words in a given plane, then the pointer
-         in the first 32 bytes of the chunk is =0.
-.2.2 Format for method 4
-         The DLTA chunk is modified slightly to have 16 long pointers at
-         the start.  The first 8 are as before - pointers to the start of
-         the data for each of the bitplanes (up to a theoretical max of 8
-         planes).  The next 8 are pointers to the start of the offset/numbers
-         data list.  If there is only one list of offset/numbers for all
-         planes, then the pointer to that list is repeated in all positions
-         so the playback code need not even be aware of it.  In fact, one
-         could get fancy and have some bitplanes share lists while others
-         have different lists, or no lists (the problems in these schemes
-         lie in the generation, not in the playback).
-         The best way to show the use of this format is in a sample playback
-         routine.
-            SetDLTAshort(bm,deltaword)
-            struct BitMap *bm;
-            WORD *deltaword;
-            {
-               int i;
-               LONG *deltadata;
-               WORD *ptr,*planeptr;
-               register int s,size,nw;
-               register WORD *data,*dest;
-               deltadata = (LONG *)deltaword;
-               nw = bm-&gt;BytesPerRow &gt;&gt;1;
-               for (i=0;i&lt;bm-&gt;Depth;i++) {
-                  planeptr = (WORD *)(bm-&gt;Planes[i]);
-                  data = deltaword + deltadata[i];
-                  ptr  = deltaword + deltadata[i+8];
-                  while (*ptr != 0xFFFF) {
-                     dest = planeptr + *ptr++;
-                     size = *ptr++;
-                     if (size &lt; 0) {
-                        for (s=size;s&lt;0;s++) {
-                           *dest = *data;
-                           dest += nw;
-                        }
-                        data++;
-                     }
-                     else {
-                        for (s=0;s&lt;size;s++) {
-                           *dest = *data++;
-                           dest += nw;
-                        }
-                     }
-                  }
-               }
-               return(0);
-            }
-         The above routine is for short word vertical compression with
-         run length compression.  The most efficient way to support
-         the various options is to replicate this routine and make
-         alterations for, say, long word or XOR.  The variable nw
-         indicates the number of words to skip to go down the vertical
-         column.  This one routine could easily handle horizontal
-         compression by simply setting nw=1.  For ultimate playback
-         speed, the core, at least, of this routine should be coded in
-         assembly language.
-.2.2 Format for method 5
-         In this method the same 16 pointers are used as in option 4.
-         The first 8 are pointers to the data for up to 8 planes.
-         The second set of 8 are not used but were retained for several
-         reasons.  First to be somewhat compatible with code for option
-(although this has not proven to be of any benefit) and
-         second, to allow extending the format for more bitplanes (code
-         has been written for up to 12 planes).
-         Compression/decompression is performed on a plane-by-plane basis.
-         For each plane, compression can be handled by the skip.c code
-         (provided Public Domain by Jim Kent) and decompression can be
-         handled by unvscomp.asm (also provided Public Domain by Jim Kent).
-         Compression/decompression is performed on a plane-by-plane basis.
-         The following description of the method is taken directly from
-         Jim Kent's code with minor re-wording.  Please refer to Jim's
-         code (skip.c and unvscomp.asm) for more details:
-            Each column of the bitplane is compressed separately.
-            A 320x200 bitplane would have 40 columns of 200 bytes each.
-            Each column starts with an op-count followed by a number
-            of ops.  If the op-count is zero, that's ok, it just means
-            there's no change in this column from the last frame.
-            The ops are of three classes, and followed by a varying
-            amount of data depending on which class:
-. Skip ops - this is a byte with the hi bit clear that
-                 says how many rows to move the &quot;dest&quot; pointer forward,
-                 ie to skip. It is non-zero.
-. Uniq ops - this is a byte with the hi bit set.  The hi
-                 bit is masked down and the remainder is a count of the
-                 number of bytes of data to copy literally.  It's of
-                 course followed by the data to copy.
-. Same ops - this is a 0 byte followed by a count byte,
-                 followed by a byte value to repeat count times.
-            Do bear in mind that the data is compressed vertically rather
-            than horizontally, so to get to the next byte in the destination
-            we add the number of bytes per row instead of one!</pre>
-=== 2-D Object standard format ===
-<pre>Description by Ross Cunniff and John Orr
-A standard IFF FORM to describe 2D drawings has been sorely needed for
-a long time.  Several commercial drawing packages have been available
-for some time but none has established its file format as the Amiga
-standard.  The absence of a 2D drawing standard hinders the
-development of applications that use 2D drawings as it forces each
-application to understand several private standards instead of a
-single one.  Without a standard, data exchange for both the developer
-and the user is difficult, if not impossible.
-The DR2D FORM fills this void.  This FORM was developed by Taliesin,
-Inc. for use as the native file format for their two-dimensional
-structured drawing package, ProVector.  Saxon Industries and Soft
-Logik Publishing Corporation are planning to support this new FORM in
-the near future.
-Many of the values stored in the DR2D FORM are stored as IEEE single
-precision floating point numbers.  These numbers consist of 32 bits,
-arranged as follows:
- _______________________________________________________________________
-| s e e e e e e e | e m m m m m m m | m m m m m m m m | m m m m m m m m |
- -----------------------------------------------------------------------
-24  23            16  15            8   7             0
-where:
-        s       is the sign of the number where 1 is negative and 0 is
-                  positive.
-        e       is the 8 bit exponent in excess 127 form.  This number
-                  is the power of two to which the mantissa is raised
-                  (Excess 127 form means that 127 is added to the
-                  exponent before packing it into the IEEE number.)
-        m       is the 23 bit mantissa.  It ranges from 1.0000000 to
-.999999..., where the leading base-ten one is
-                  assumed.
-An IEEE single precision with the value of 0.0000000 has all its bits
-cleared.
-The DR2D Chunks
-FORM (0x464F524D)       /* All drawings are a FORM */
-        struct FORMstruct {
-            ULONG       ID;             /* DR2D */
-            ULONG       Size;
-        };
-DR2D (0x44523244)  /* ID of 2D drawing */
-The DR2D chunks are broken up into three groups: the global drawing
-attribute chunks, the object attribute chunks, and the object chunks.
-The global drawing attribute chunks describe elements of a 2D drawing
-that are common to many objects in the drawing.  Document preferences,
-palette information, and custom fill patterns are typical
-document-wide settings defined in global drawing attribute chunks.
-The object attribute chunks are used to set certain properties of the
-object chunk(s) that follows the object attribute chunk.  The current
-fill pattern, dash pattern, and line color are all set using an object
-attribute chunk.  Object chunks describe the actual DR2D drawing.
-Polygons, text, and bitmaps are found in these chunks.
-The Global Drawing Attribute Chunks
-The following chunks describe global attributes of a DR2D document.
-DRHD (0x44524844)       /* Drawing header */
-The DRHD chunk contains the upper left and lower right extremes of the
-document in (X, Y) coordinates.  This chunk is required and should
-only appear once in a document in the outermost layer of the DR2D file
-(DR2Ds can be nested).
-        struct DRHDstruct {
-            ULONG       ID;
-            ULONG       Size;                   /* Always 16 */
-            IEEE        XLeft, YTop,
-                        XRight, YBot;
-        };
-The point (XLeft,YTop) is the upper left corner of the project and the
-point (XRight,YBot) is its lower right corner.  These coordinates not
-only supply the size and position of the document in a coordinate
-system, they also supply the project's orientation.  If XLeft &lt;
-XRight, the X-axis increases toward the right.  If YTop &lt; YBot, the
-Y-axis increases toward the bottom.  Other combinations are possible;
-for example in Cartesian coordinates, XLeft would be less than XRight
-but YTop would be greater than YBot.
-PPRF (0x50505249)       /* Page preferences */
-The PPRF chunk contains preference settings for ProVector.  Although
-this chunk is not required, its use is encouraged because it contains
-some important environment information.
-        struct PPRFstruct {
-            ULONG       ID;
-            ULONG       Size;
-            char        Prefs[Size];
-        };
-DR2D stores preferences as a concatenation of several null-terminated
-strings, in the Prefs[] array.  The strings can appear in any order.
-The currently supported strings are:
-                Units=&lt;unit-type&gt;
-                Portrait=&lt;boolean&gt;
-                PageType=&lt;page-type&gt;
-                GridSize=&lt;number&gt;
-where:
-                &lt;unit-type&gt;     is either Inch, Cm, or Pica
-                &lt;boolean&gt;       is either True or False
-                &lt;page-type&gt;     is either Standard, Legal, B4, B5, A3,
-                                  A4, A5, or Custom
-                &lt;number&gt;        is a floating-point number
-The DR2D FORM does not require this chunk to explicitly state all the
-possible preferences.  In the absence of any particular preference
-string, a DR2D reader should fall back on the default value.  The
-defaults are:
-                Units=Inch
-                Portrait=True
-                PageType=Standard
-                GridSize=1.0
-CMAP (0x434D4150)       /* Color map (Same as ILBM CMAP) */
-This chunk is identical to the ILBM CMAP chunk as described in the IFF
-ILBM documentation.
-        struct CMAPstruct {
-            ULONG       ID;
-            ULONG       Size;
-            UBYTE       ColorMap[Size];
-        };
-ColorMap is an array of 24-bit RGB color values.  The 24-bit value is
-spread across three bytes, the first of which contains the red
-intensity, the next contains the green intensity, and the third
-contains the blue intensity.  Because DR2D stores its colors with
--bit accuracy, DR2D readers must not make the mistake that some ILBM
-readers do in assuming the CMAP chunk colors correspond directly to
-Amiga color registers.
-FONS (0x464F4E53)       /* Font chunk (Same as FTXT FONS chunk) */
-The FONS chunk contains information about a font used in the DR2D
-FORM.  ProVector does not include support for Amiga fonts.  Instead,
-ProVector uses fonts defined in the OFNT FORM which is documented
-later in this article.
-        struct FONSstruct {
-            ULONG       ID;
-            ULONG       Size;
-            UBYTE       FontID;         /* ID the font is referenced by */
-            UBYTE       Pad1;           /* Always 0 */
-            UBYTE       Proportional;   /* Is it proportional? */
-            UBYTE       Serif;          /* does it have serifs? */
-            CHAR        Name[Size-4];   /* The name of the font */
-        };
-The UBYTE FontID field is the number DR2D assigns to this font.
-References to this font by other DR2D chunks are made using this
-number.
-The Proportional and Serif fields indicate properties of this font.
-Specifically, Proportional indicates if this font is proportional, and
-Serif indicates if this font has serifs.  These two options were
-created to allow for font substitution in case the specified font is
-not available.  They are set according to these values:
-The DR2D writer didn't know if this font is
-                  proportional/has serifs.
-No, this font is not proportional/does not have
-                  serifs.
-Yes, this font is proportional/does have serifs.
-The last field, Name[], is a NULL terminated string containing the
-name of the font.
-DASH (0x44415348)       /* Line dash pattern for edges */
-This chunk describes the on-off dash pattern associated with a line.
-        struct DASHstruct {
-            ULONG       ID;
-            ULONG       Size;
-            USHORT      DashID;                 /* ID of the dash pattern */
-            USHORT      NumDashes;              /* Should always be even */
-            IEEE        Dashes[NumDashes];      /* On-off pattern */
-        };
-DashID is the number assigned to this specific dash pattern.
-References to this dash pattern by other DR2D chunks are made using
-this number.
-The Dashes[] array contains the actual dash pattern.  The first number
-in the array (element 0) is the length of the ``on'' portion of the
-pattern.  The second number (element 1) specifies the ``off'' portion
-of the pattern.  If there are more entries in the Dashes array, the
-pattern will continue.  Even-index elements specify the length of an
-``on'' span, while odd-index elements specify the length of an ``off''
-span.  There must be an even number of entries.  These lengths are not
-in the same units as specified in the PPRF chunk, but are multiples of
-the line width, so a line of width 2.5 and a dash pattern of 1.0, 2.0
-would have an ``on'' span of length 1.0 x 2.5 = 2.5 followed by an
-``off'' span of length 2.0 x 2.5 = 5.  The following figure shows
-several dash pattern examples.  Notice that for lines longer than the
-dash pattern, the pattern repeats.
-[figure 1 - dash patterns]
-By convention, DashID 0 is reserved to mean `No line pattern at all',
-i.e. the edges are invisible.  This DASH pattern should not be defined
-by a DR2D DASH chunk.  Again by convention, a NumDashes of 0 means
-that the line is solid.
-AROW (0x41524F57)       /* An arrow-head pattern */
-The AROW chunk describes an arrowhead pattern.  DR2D open polygons
-(OPLY) can have arrowheads attached to their endpoints.  See the
-description of the OPLY chunk later in this article for more
-information on the OPLY chunk.
-        #define ARROW_FIRST  0x01 /* Draw an arrow on the OPLY's first point */
-        #define ARROW_LAST   0x02 /* Draw an arrow on the OPLY's last point */
-        struct AROWstruct {
-            ULONG       ID;
-            ULONG       Size;
-            UBYTE       Flags;          /* Flags, from ARROW_*, above */
-            UBYTE       Pad0;           /* Should always 0 */
-            USHORT      ArrowID;        /* Name of the arrow head */
-            USHORT      NumPoints;
-            IEEE        ArrowPoints[NumPoints*2];
-        };
-The Flags field specifies which end(s) of an OPLY to place an
-arrowhead based on the #defines above.  ArrowID is the number by which
-an OPLY will reference this arrowhead pattern.
-The coordinates in the array ArrowPoints[] define the arrowhead's
-shape.  These points form a closed polygon.  See the section on the
-OPLY/CPLY object chunks for a descriptionof how DR2D defines shapes.
-The arrowhead is drawn in the same coordinate system relative to the
-endpoint of the OPLY the arrowhead is attached to.  The arrowhead's
-origin (0,0) coincides with the OPLY's endpoint.  DR2D assumes that
-the arrowhead represented in the AROW chunk is pointing to the right
-so the proper rotation can be applied to the arrowhead.  The arrow is
-filled according to the current fill pattern set in the ATTR object
-attribute chunk.
-FILL (0x46494C4C)       /* Object-oriented fill pattern */
-The FILL chunk defines a fill pattern.  This chunk is only valid
-inside nested DR2D FORMs.  The GRUP object chunk section of this
-article contans an example of the FILL chunk.
-        struct FILLstruct {
-            ULONG       ID;
-            ULONG       Size;
-            USHORT      FillID;                 /* ID of the fill */
-        };
-FillID is the number by which the ATTR object attribute chunk
-references fill patterns.  The FILL chunk must be the first chunk
-inside a nested DR2D FORM.  A FILL is followed by one DR2D object plus
-any of the object attribute chunks (ATTR, BBOX) associated with the
-object.
-[Figure 2 - fill patterns]
-DR2D makes a ``tile'' out of the fill pattern, giving it a virtual
-bounding box based on the extreme X and Y values of the FILL's object
-(Fig. A).  The bounding box shown in Fig. A surrounding the pattern
-(the two ellipses) is invisible to the user.  In concept, this
-rectangle is pasted on the page left to right, top to bottom like
-floor tiles (Fig. B).  Again, the bounding boxes are not visible.  The
-only portion of this tiled pattern that is visible is the part that
-overlaps the object (Fig. C) being filled.  The object's path is
-called a clipping path, as it ``clips'' its shape from the tiled
-pattern (Fig. D).  Note that the fill is only masked on top of
-underlying objects, so any ``holes'' in the pattern will act as a
-window, leaving visible underlying objects.
-LAYR (0x4C415952)       /* Define a layer */
-A DR2D project is broken up into one or more layers.  Each DR2D object
-is in one of these layers.  Layers provide several useful features.
-Any particular layer can be ``turned off'', so that the objects in the
-layer are not displayed.  This eliminates the unnecessary display of
-objects not currently needed on the screen.  Also, the user can lock a
-layer to protect the layer's objects from accidental changes.
-        struct LAYRstruct {
-            ULONG    ID;
-            ULONG    Size;
-            USHORT   LayerID;              /* ID of the layer */
-            char     LayerName[16];        /* Null terminated and padded */
-            UBYTE    Flags;                /* Flags, from LF_*, below */
-            UBYTE    Pad0;                 /* Always 0 */
-        };
-LayerID is the number assigned to this layer.  As the field's name
-indicates, LayerName[] is the NULL terminated name of the layer.
-Flags is a bit field who's bits are set according to the #defines
-below:
-        #define LF_ACTIVE       0x01    /* Active for editing */
-        #define LF_DISPLAYED    0x02    /* Displayed on the screen */
-If the LF_ACTIVE bit is set, this layer is unlocked.  A set
-LF_DISPLAYED bit indicates that this layer is currently visible on the
-screen.  A cleared LF_DISPLAYED bit implies that LF_ACTIVE is not set.
-The reason for this is to keep the user from accidentally editing
-layers that are invisible.
-The Object Attribute Chunks
-ATTR (0x41545452)       /* Object attributes */
-The ATTR chunk sets various attributes for the objects that follow it.
-The attributes stay in effect until the next ATTR changes the
-attributes, or the enclosing FORM ends, whichever comes first.
-        /* Various fill types */
-        #define FT_NONE         0    /* No fill                 */
-        #define FT_COLOR        1    /* Fill with color from palette */
-        #define FT_OBJECTS      2    /* Fill with tiled objects */
-        struct ATTRstruct {
-            ULONG       ID;
-            ULONG       Size;
-            UBYTE       FillType;    /* One of FT_*, above      */
-            UBYTE       JoinType;    /* One of JT_*, below      */
-            UBYTE       DashPattern; /* ID of edge dash pattern */
-            UBYTE       ArrowHead;   /* ID of arrowhead to use  */
-            USHORT      FillValue;   /* Color or object with which to fill */
-            USHORT      EdgeValue;   /* Edge color index        */
-            USHORT      WhichLayer;  /* ID of layer it's in     */
-            IEEE        EdgeThick;   /* Line width              */
-        };
-FillType specifies what kind of fill to use on this ATTR chunk's
-objects.  A value of FT_NONE means that this ATTR chunk's objects are
-not filled.  FT_COLOR indicates that the objects should be filled in
-with a color.  That color's ID (from the CMAP chunk) is stored in the
-FillValue field.  If FillType is equal to FT_OBJECTS, FillValue
-contains the ID of a fill pattern defined in a FILL chunk.
-JoinType determines which style of line join to use when connecting
-the edges of line segments.  The field contains one of these four
-values:
-        /* Join types */
-        #define JT_NONE    0            /* Don't do line joins */
-        #define JT_MITER        1       /* Mitered join */
-        #define JT_BEVEL        2       /* Beveled join */
-        #define JT_ROUND        3       /* Round join */
-DashPattern and ArrowHead contain the ID of the dash pattern and arrow
-head for this ATTR's objects.  A DashPattern of zero means that there
-is no dash pattern so lines will be invisible.  If ArrowHead is 0,
-OPLYs have no arrow head.  EdgeValue is the color of the line
-segments.  WhichLayer contains the ID of the layer this ATTR's objects
-are in.  EdgeThick is the width of this ATTR's line segments.
-BBOX (0x42424F48)       /* Bounding box of next object in FORM */
-The BBOX chunk supplies the dimensions and position of a bounding box
-surrounding the DR2D object that follows this chunk in the FORM.  A
-BBOX chunk can apply to a FILL or AROW as well as a DR2D object.  The
-BBOX chunk appears just before its DR2D object, FILL, or AROW chunk.
-        struct BBOXstruct {
-            ULONG       ID;
-            ULONG       Size;
-            IEEE                XMin, YMin,     /* Bounding box of obj. */
-                                XMax, YMax;     /* including line width */
-        };
-In a Cartesian coordinate system, the point (XMin, YMin) is the
-coordinate of the lower left hand corner of the bounding box and
-(XMax, YMax) is the upper right.  These coordinates take into
-consideration the width of the lines making up the bounding box.
-XTRN (0x5854524E)       /* Externally controlled object */
-The XTRN chunk was created primarily to allow ProVector to link DR2D
-objects to ARexx functions.
-        struct XTRNstruct {
-            ULONG   ID;
-            ULONG   Size;
-            short   ApplCallBacks;             /* From #defines, below */
-            short   ApplNameLength;
-            char    ApplName[ApplNameLength];  /* Name of ARexx func to call */
-        };
-ApplName[] contains the name of the ARexx script ProVector calls when
-the user manipulates the object in some way.  The ApplCallBacks field
-specifies the particular action that triggers calling the ARexx script
-according to the #defines listed below.
-        /* Flags for ARexx script callbacks */
-        #define    X_CLONE     0x0001    /* The object has been cloned */
-        #define    X_MOVE      0x0002    /* The object has been moved */
-        #define    X_ROTATE    0x0004    /* The object has been rotated */
-        #define    X_RESIZE    0x0008    /* The object has been resized */
-        #define    X_CHANGE    0x0010    /* An attribute (see ATTR) of the
-                                            object has changed */
-        #define    X_DELETE    0x0020    /* The object has been deleted */
-        #define    X_CUT       0x0040    /* The object has been deleted, but
-                                            stored in the clipboard */
-        #define    X_COPY      0x0080    /* The object has been copied to the
-                                            clipboard */
-        #define    X_UNGROUP   0x0100    /* The object has been ungrouped */
-For example, given the XTRN object:
-        FORM xxxx DR2D {
-                XTRN xxxx { X_RESIZE | X_MOVE, 10, &quot;Dimension&quot; }
-                ATTR xxxx { 0, 0, 1, 0, 0, 0, 0.0 }
-                FORM xxxx DR2D {
-                        GRUP xxxx { 2 }
-                        STXT xxxx { 0, 0.5, 1.0, 6.0, 5.0, 0.0, 4, &quot;3.0&quot; }
-                        OPLY xxxx { 2, { 5.5, 5.5, 8.5, 5.5 } }
-                }
-        }
-ProVector would call the ARexx script named Dimension if the user
-resized or moved this object.  What exactly ProVector sends depends
-upon what the user does to the object.  The following list shows what
-string(s) ProVector sends according to which flag(s) are set.  The
-parameters are described below.
-        X_CLONE     ``appl CLONE objID dx dy''
-        X_MOVE      ``appl MOVE objID dx dy''
-        X_ROTATE    ``appl ROTATE objID cx cy angle''
-        X_RESIZE    ``appl RESIZE objID cx cy sx sy''
-        X_CHANGE    ``appl CHANGE objID et ev ft fv ew jt fn''
-        X_DELETE    ``appl DELETE objID''
-        X_CUT       ``appl CUT objID''
-        X_COPY      ``appl COPY objID''
-        X_UNGROUP   ``appl UNGROUP objID''
-where:
-        appl is the name of the ARexx script
-        CLONE, MOVE, ROTATE, RESIZE, etc. are literal strings
-        objID is the object ID that ProVector assigns to this object
-        (dx, dy) is the position offset of the CLONE or MOVE
-        (cx, cy) is the point around which the object is rotated or resized
-        angle is the angle (in degrees) the object is rotated
-        sx and sy are the scaling factors in the horizontal and
-          vertical directions, respectively.
-        et is the edge type (the dash pattern index)
-        ev is the edge value (the edge color index)
-        ft is the fill type
-        fv is the fill index
-        ew is the edge weight
-        jt is the join type
-        fn is the font name
-The X_CHANGE message reflects changes to the attributes found in the
-ATTR chunk.
-If the user resized the XTRN object shown above by factor of 2,
-ProVector would call the ARexx script Dimension like this:
-        Dimension RESIZE 1985427 7.0 4.75 2.0 2.0
-The Object Chunks
-The following chunks define the objects available in the DR2D FORM.
-VBM  (0x56424D20)       /* Virtual BitMap */
-The VBM chunk contains the position, dimensions, and file name of an
-ILBM image.
-struct VBMstruct {
-    IEEE        XPos, YPos,     /* Virtual coords */
-                XSize, YSize,   /* Virtual size */
-                Rotation;       /* in degrees */
-    USHORT      PathLen;        /* Length of dir path */
-    char        Path[PathLen];  /* Null-terminated path of file */
-};
-The coordinate (XPos, YPos) is the position of the upper left hand
-corner of the bitmap and the XSize and YSize fields supply the x and y
-dimensions to which the image should be scaled.  Rotation tells how
-many degrees to rotate the ILBM around its upper left hand corner.
-ProVector does not currently support rotation of bitmaps and will
-ignore this value.  Path contains the name of the ILBM file and may
-also contain a partial or full path to the file.  DR2D readers should
-not assume the path is correct.  The full path to an ILBM on one
-system may not match the path to the same ILBM on another system.  If
-a DR2D reader cannot locate an ILBM file based on the full path name
-or the file name itself (looking in the current directory), it should
-ask the user where to find the image.
-CPLY (0x43504C59)       /* Closed polygon */
-OPLY (0x4F504C59)       /* Open polygon */
-Polygons are the basic components of almost all 2D objects in the DR2D
-FORM.  Lines, squares, circles, and arcs are all examples of DR2D
-polygons.  There are two types of DR2D polygons, the open polygon
-(OPLY) and the closed polygon (CPLY).  The difference between a closed
-and open polygon is that the computer adds a line segment connecting
-the endpoints of a closed polygon so that it is a continuous path.  An
-open polygon's endpoints do not have to meet, like the endpoints of a
-line segment.
-        struct POLYstruct {
-            ULONG       ID;
-            ULONG       Size;
-            USHORT      NumPoints;
-            IEEE        PolyPoints[2*NumPoints];
-        };
-The NumPoints field contains the number of points in the polygon and
-the PolyPoints array contains the (X, Y) coordinates of the points of
-the non-curved parts of polygons.  The even index elements are X
-coordinates and the odd index elements are Y coordinates.
-[Figure 3 - Bezier curves]
-DR2D uses Bezier cubic sections, or cubic splines, to describe curves
-in polygons.  A set of four coordinates (P1 through P4) defines the
-shape of a cubic spline.  The first coordinate (P1) is the point where
-the curve begins.  The line from the first to the second coordinate
-(P1 to P2) is tangent to the curve at the first point.  The line from
-P3 to P4 is tangent to the cubic section, where it ends at P4.
-The coordinates describing the cubic section are stored in the
-PolyPoints[] array with the coordinates of the normal points.  DR2D
-inserts an indicator point before a set of cubic section points to
-differentiate a normal point from the points that describe a curve.
-An indicator point has an X value of 0xFFFFFFFF.  The indicator
-point's Y value is a bit field.  If this bit field's low-order bit is
-set, the points that follow the indicator point make up a cubic
-section.
-The second lowest order bit in the indicator point's bit field is the
-MOVETO flag.  If this bit is set, the point (or set of cubic section
-points) starts a new polygon, or subpolygon.  This subpolygon will
-appear to be completely separate from other polygons but there is an
-important connection between a polygon and its subpolygon.
-Subpolygons make it possible to create holes in polygons.  An example
-of a polygon with a hole is the letter ``O''.  The ``O'' is a filled
-circular polygon with a smaller circular polygon within it.  The
-reason the inner polygon isn't covered up when the outer polygon is
-filled is that DR2D fills are done using the even-odd rule.
-The even-odd rule determines if a point is ``inside'' a polygon by
-drawing a ray outward from that point and counting the number of path
-segments the ray crosses.  If the number is even, the point is outside
-the object and shouldn't be filled.  Conversely, an odd number of
-crossings means the point is inside and should be filled.  DR2D only
-applies the even-odd rule to a polygon and its subpolygons, so no
-other objects are considered in the calculations.
-Taliesin, Inc. supplied the following algorithm to illustrate the
-format of DR2D polygons.  OPLYs, CPLYs, AROWs, and ProVector's outline
-fonts all use the same format:
-        typedef union {
-            IEEE num;
-            LONG bits;
-        } Coord;
-        #define INDICATOR       0xFFFFFFFF
-        #define IND_SPLINE      0x00000001
-        #define IND_MOVETO      0x00000002
-        /* A common pitfall in attempts to support DR2D has
-                been to fail to recognize the case when an
-                INDICATOR point indicates the following
-                coordinate to be the first point of BOTH a
-                Bezier cubic and a sub-polygon, ie. the
-                value of the flag = (IND_CURVE | IND_MOVETO) */
-        Coord   Temp0, Temp1;
-        int     FirstPoint, i, Increment;
-        /* Initialize the path */
-        NewPath();
-        FirstPoint = 1;
-        /* Draw the path */
-        i = 0;
-        while( i &lt; NumPoints ) {
-            Temp0.num = PolyPoints[2*i];    Temp1.num = PolyPoints[2*i + 1];
-            if( Temp0.bits == INDICATOR ) {
-                /* Increment past the indicator */
-                Increment = 1;
-                if( Temp1.bits &amp; IND_MOVETO ) {
-                    /* Close and fill, if appropriate */
-                    if( ID == CPLY ) {
-                        FillPath();
-                    }
-                    else {
-                        StrokePath();
-                    }
-                    /* Set up the new path */
-                    NewPath();
-                    FirstPoint = 1;
-                }
-                if( Temp1.bits &amp; IND_CURVE ) {
-                    /* The next 4 points are Bezier cubic control points */
-                    if( FirstPoint )
-                        MoveTo( PolyPoints[2*i + 2], PolyPoints[2*i + 3] );
-                    else
-                        LineTo( PolyPoints[2*i + 2], PolyPoints[2*i + 3] );
-                    CurveTo(    PolyPoints[2*i + 4], PolyPoints[2*i + 5],
-                                PolyPoints[2*i + 6], PolyPoints[2*i + 7],
-                                PolyPoints[2*i + 8], PolyPoints[2*i + 9] );
-                    FirstPoint = 0;
-                    /* Increment past the control points */
-                    Increment += 4;
-                }
-            }
-            else {
-                if( FirstPoint )
-                    MoveTo(     PolyPoints[2*i], PolyPoints[2*i + 1] );
-                else
-                    LineTo(     PolyPoints[2*i], PolyPoints[2*i + 1] );
-                FirstPoint = 0;
-                /* Increment past the last endpoint */
-                Increment = 1;
-            }
-            /* Add the increment */
-            i += Increment;
-        }
-        /* Close the last path */
-        if( ID == CPLY ) {
-            FillPath();
-        }
-        else {
-            StrokePath();
-        }
-GRUP (0x47525550)       /* Group */
-The GRUP chunk combines several DR2D objects into one.  This chunk is
-only valid inside nested DR2D FORMs, and must be the first chunk in
-the FORM.
-        struct GROUPstruct {
-            ULONG       ID;
-            ULONG       Size;
-            USHORT      NumObjs;
-        };
-The NumObjs field contains the number of objects contained in this
-group.  Note that the layer of the GRUP FORM overrides the layer of
-objects within the GRUP.  The following example illustrates the layout
-of the GRUP (and FILL) chunk.
-       FORM { DR2D              /* Top-level drawing... */
-                DRHD { ... }    /* Confirmed by presence of DRHD chunk */
-                CMAP { ... }    /* Various other things... */
-                FONS { ... }
-                FORM { DR2D             /* A nested form... */
-                        FILL { 1 }      /* Ah!  The fill-pattern table */
-                        CPLY { ... }    /* with only 1 object */
-                }
-                FORM { DR2D             /* Yet another nested form */
-                        GRUP { ..., 3 } /* Ah! A group of 3 objects */
-                        TEXT { ... }
-                        CPLY { ... }
-                        OPLY { ... }
-                }
-                FORM { DR2D             /* Still another nested form */
-                        GRUP { ..., 2 } /* A GRUP with 2 objects */
-                        OPLY { ... }
-                        TEXT { ... }
-                }
-        }
-STXT (0x53545854)               /* Simple text */
-The STXT chunk contains a text string along with some information on
-how and where to render the text.
-        struct STXTstruct {
-            ULONG       ID;
-            ULONG       Size;
-            UBYTE       Pad0;           /* Always 0 (for future expansion) */
-            UBYTE       WhichFont;      /* Which font to use */
-            IEEE        CharW, CharH,   /* W/H of an individual char */
-                        BaseX, BaseY,   /* Start of baseline */
-                        Rotation;       /* Angle of text (in degrees) */
-            USHORT      NumChars;
-            char        TextChars[NumChars];
-        };
-The text string is in the character array, TextChars[].  The ID of the
-font used to render the text is WhichFont.  The font's ID is set in a
-FONS chunk.  The starting point of the baseline of the text is (BaseX,
-BaseY).  This is the point around which the text is rotated.  If the
-Rotation field is zero (degrees), the text's baseline will originate
-at (BaseX, BaseY) and move to the right.  CharW and CharH are used to
-scale the text after rotation.  CharW is the average character width
-and CharH is the average character height.  The CharW/H fields are
-comparable to an X and Y font size.
-TPTH (0x54505448)               /* A text string along a path */
-This chunk defines a path (polygon) and supplies a string to render
-along the edge of the path.
-        struct TPTHstruct {
-            ULONG   ID;
-            ULONG   Size;
-            UBYTE   Justification;      /* see defines, below */
-            UBYTE   WhichFont;          /* Which font to use */
-            IEEE    CharW, CharH;       /* W/H of an individual char    */
-            USHORT  NumChars;           /* Number of chars in the string */
-            USHORT  NumPoints;          /* Number of points in the path */
-            char    TextChars[NumChars];/* PAD TO EVEN #! */
-            IEEE    Path[2*NumPoints];  /* The path on which the text lies */
-        };
-WhichFont contains the ID of the font used to render the text.
-Justification controls how the text is justified on the line.
-Justification can be one of the following values:
-        #define J_LEFT          0x00    /* Left justified */
-        #define J_RIGHT         0x01    /* Right justified */
-        #define J_CENTER        0x02    /* Center text */
-        #define J_SPREAD        0x03    /* Spread text across path */
-CharW and CharH are the average width and height of the font
-characters and are akin to X and Y font sizes, respectively.  A
-negative FontH implies that the font is upsidedown.  Note that CharW
-must not be negative.  NumChars is the number of characters in the
-TextChars[] string, the string containing the text to be rendered.
-NumPoints is the number of points in the Path[] array.  Path[] is the
-path along which the text is rendered.  The path itself is not
-rendered.  The points of Path[] are in the same format as the points
-of a DR2D polygon.
-A Simple DR2D Example
-Here is a (symbolic) DR2D FORM:
-    FORM { DR2D
-            DRHD 16 { 0.0, 0.0, 10.0, 8.0 }
-            CMAP  6 { 0,0,0, 255,255,255 }
-            FONS  9 { 1, 0, 1, 0, &quot;Roman&quot; } 0
-            DASH 12 { 1, 2, {1.0, 1.0} }
-            ATTR 14 { 0, 0, 1, 0, 0, 0, 0, 0.0 }
-            BBOX 16 { 2.0, 2.0, 8.0, 6.0 }
-            FORM { DR2D
-                  GRUP  2 { 2 }
-                  BBOX 16 { 3.0, 4.0, 7.0, 5.0 }
-                  STXT 36 { 0,1, 0.5, 1.0, 3.0, 5.0, 0.0, 12, &quot;Hello, World&quot; }
-                  BBOX 16 { 2.0, 2.0, 8.0, 6.0 }
-                  OPLY 42 { 5, {2.0,2.0, 8.0,2.0, 8.0,6.0, 2.0,6.0, 2.0,2.0 }
-            }
-    }
-[Figure 4 - Simple DR2D drawing]
-The OFNT FORM
-OFNT    (0x4F464E54)    /* ID of outline font file */
-ProVector's outline fonts are stored in an IFF FORM called OFNT.  This
-IFF is a separate file from a DR2D.  DR2D's FONS chunk refers only to
-fonts defined in the OFNT form.
-OFHD    (0x4F464844)    /* ID of OutlineFontHeaDer */
-This chunk contains some basic information on the font.
-        struct OFHDstruct {
-            char   FontName[32];   /* Font name, null padded */
-            short  FontAttrs;      /* See FA_*, below */
-            IEEE   FontTop,        /* Typical height above baseline */
-                   FontBot,        /* Typical descent below baseline */
-                   FontWidth;      /* Typical width, i.e. of the letter O */
-        };
-        #define FA_BOLD         0x0001
-        #define FA_OBLIQUE      0x0002
-        #define FA_SERIF        0x0004
-The FontName field is a NULL terminated string containing the name of
-this font.  FontAttrs is a bit field with flags for several font
-attributes.  The flags, as defined above, are bold, oblique, and
-serif.  The unused higher order bits are reserved for later use.  The
-other fields describe the average dimensions of the characters in this
-font.  FontTop is the average height above the baseline, FontBot is
-the average descent below the baseline, and FontWidth is the average
-character width.
-KERN    (0x4B45524C)    /* Kerning pair */
-The KERN chunk describes a kerning pair.  A kerning pair sets the
-distance between a specific pair of characters.
-struct KERNstruct {
-    short   Ch1, Ch2;           /* The pair to kern (allows for 16 bits...) */
-    IEEE    XDisplace,          /* Amount to displace -left +right */
-            YDisplace;          /* Amount to displace -down +up */
-};
-The Ch1 and Ch2 fields contain the pair of characters to kern.  These
-characters are typically stored as ASCII codes.  Notice that OFNT
-stores the characters as a 16-bit value.  Normally, characters are
-stored as 8-bit values.  The wary programmer will be sure to cast
-assigns properly to avoid problems with assigning an 8-bit value to a
--bit variable.  The remaining fields, XDisplace and YDisplace,
-supply the baseline shift from Ch1 to Ch2.
-CHDF    (0x43484446)    /* Character definition */
-This chunk defines the shape of ProVector's outline fonts.
-struct CHDFstruct {
-    short   Ch;         /* The character we're defining (ASCII) */
-    short   NumPoints;  /* The number of points in the definition */
-    IEEE    XWidth,     /* Position for next char on baseline - X */
-            YWidth;     /* Position for next char on baseline - Y */
- /* IEEE    Points[2*NumPoints]*/       /* The actual points */
-};
-#define INDICATOR       0xFFFFFFFF      /* If X == INDICATOR, Y is an action */
-#define IND_SPLINE      0x00000001      /* Next 4 pts are spline control pts */
-#define IND_MOVETO      0x00000002         /* Start new subpoly */
-#define IND_STROKE      0x00000004      /* Stroke previous path */
-#define IND_FILL        0x00000008      /* Fill previous path */
-Ch is the value (normally ASCII) of the character outline this chunk
-defines.  Like Ch1 and Ch2 in the KERN chunk, Ch is stored as a 16-bit
-value.  (XWidth,YWidth) is the offset to the baseline for the
-following character.  OFNT outlines are defined using the same method
-used to define DR2D's polygons (see the description of OPLY/CPLY for
-details).
-Because the OFNT FORM does not have an ATTR chunk, it needed an
-alternative to make fills and strokes possible.  There are two extra
-bits used in font indicator points not found in polygon indicator
-points, the IND_STROKE and IND_FILL bits (see defines above).  These
-two defines describe how to render the current path when rendering
-fonts.
-The current path remains invisible until the path is either filled
-and/or stroked.  When the IND_FILL bit is set, the currently defined
-path is filled in with the current fill pattern (as specified in the
-current ATTR chunk).  A set IND_STROKE bit indicates that the
-currently defined path itself should be rendered.  The current ATTR's
-chunk dictates the width of the line, as well as several other
-attributes of the line.  These two bits apply only to the OFNT FORM
-and should not be used in describing DR2D polygons.</pre>
-=== Fantavision movie format ===
-<pre>FORM FANT
-/*********************************************************************/
-/*                                                                   **
-** - FantForm.h                                                      **
-**                                                                   **
-**     This is the IFF movie format for Amiga Fantavision.           **
-**                                                                   **
-**     (c) Copyright 1988 Broderbund Software                        **
-**                                                                   **
-**     - FORMAT FROZED May 5, 1988 -                                 **
-**                                                                   **
-**     Implemented by Steve Hales                                    **
-**                                                                   **
-** Overvue -                                                         **
-**     This is a description of the format used for Amiga            **
-**     Fantavision.  It assumes you have intimate knowledge of how   **
-**     IFF-FORMs are constructed, layed out, and read.  This file    **
-**     can be used as a header file.  This is fairly complete, but   **
-**     I'm sure there are a few things missing.                      **
-**                                                                   **
-**     I can be reached in the following ways:                       **
-**       UseNet:   Steve_A_Hales@cup.portal.com  OR                  **
-**                 sun!cup.portal.com!Steve_A_Hales                  **
-**                                                                   **
-**       US Mail:  882 Hagemann Drive                                **
-**                 Livermore, CA, 94550-2420                         **
-**                                                                   **
-**       Phone:    (415) 449-5297                                    **
-**                                                                   **
-**     NOTE:  I cannot, by contract, give out any code to load or    **
-**            play Fantavision movies.  If that is want you want     **
-**            then you will need to contact Broderbund Software      **
-**            directly.  Their number is (415) 492-3200.             **
-**                                                                   **
-** Enjoy!  Aloha.                                                    **
-**                                                                   */
-/*********************************************************************/
-/* Misc Fantavision structures
-*/
-typedef struct Rect
-{
-   int left, top, right, bottom;
-};
-typedef struct Point
-{
-   int h, v;
-};
-/* Frame opcodes */
-#define opNEXT     0       /* go on to next frame */
-#define opREPEAT   1       /* repeat sequence starting from frame Parm rep1 times */
-#define opGOTO     2       /* goto frame Parm */
-/* Frame modes */
-#define fNORMAL    0x0000  /* redraw every frame */
-#define fTRACE     0x0001  /* draw into both paged screens */
-#define fLIGHTNING 0x0020  /* don't erase background */
-/* Fantavision FORM defines
-*/
-#define ID_FANT    'FANT'          /* FORM type */
-#define ID_FHDR    'FHDR'          /* Movie Header */
-#define ID_FRAM    'FRAM'          /* Format info for a Frame */
-#define ID_POLY    'POLY'          /* Format info for a Polygon */
-#define ID_CSTR    'CSTR'          /* \0 terminated string */
-/* Polygon modes */
-#define pTYPEMASK  0x00FF      /* type mask to get just type of poly */
-#define pSELECT    0x8000      /* is object selected? */
-#define pOUTLINE   0x4000      /* outlined polygon using DotModeSide to
-                               ** determine when to not connect a line.
-                               ** ex. 0 draws on all sides, 1 will draw on
-                               ** everyother side, 2 will leave every second
-                               ** side blank, 3 will every third side
-                               ** blank, etc. */
-#define pBACKDROP  0x2000      /* polygon will be dropped into the background
-                               ** during animation. */
-#define pMSKBITMAP 0x1000      /* bitmap has a mask */
-/* Polygon types */
-#define pDELETE    0x7000      /* object is a filler (its deleted from display) */
-#define pFILLED    0           /* filled polygon */
-#define pLINE      1           /* not-connected line polygon */
-#define pLINED     2           /* connected line polygon */
-#define pTEXTBLOCK 3           /* text block to draw */
-#define pCIRCLEDOT 4           /* draw circle dots at vertex's using
-                               ** dotSize at size. */
-#define pRECTDOT   5           /* draw square dots at vertex's using
-                               ** dotSize at size. */
-#define pBITMAPDOT 6           /* draw dots using a bitmap at vertex's using
-                               ** BitMap. */
-#define pBITMAP    7           /* draw just bitmap image */
-/* These are used for the pTEXTBLOCK polygon type
-*/
-/* Text justification
-*/
-#define tLEFT      0
-#define tCENTER    1
-#define tRIGHT     2
-/* Text style
-*/
-#define tNORMAL    (int)(FS_NORMAL)
-#define tBOLD      (int)(FSF_BOLD)
-#define tITALIC    (int)(FSF_ITALIC)
-#define tUNDERLINE (int)(FSF_UNDERLINED)
-#define tEXTENDED  (int)(FSF_EXTENDED)
-/* Fantavision movie header -
-**
-**     This header defines how much RAM is needed, how many frames, and sounds
-**     in the movie.
-*/
-typedef struct FantHeader
-{
-   int PointsPerObj;       /* number of vertexs per object */
-   int ObjsPerFrame;       /* number of objects per frame */
-   int ScreenDepth;        /* 0 to 6, for number of bit planes */
-   int ScreenWidth;        /* in pixels */
-   int ScreenHeight;       /* in pixels */
-   int BackColor;          /* background color palette number */
-   long SizeOfMovie;       /* RAM Size of movie, expanded */
-   int pad[30];            /* padding for expanding */
-   int NumberOfFrames;
-   int NumberOfSounds;
-   int NumberOfBitMaps;
-   int Background;         /* non-zero if first bitmap is a background */
-   int SpeedOfMovie;       /* 100 is normal speed, 50 is half speed, etc */
-   int pad[3];             /* expansion */
-};
-/* Fantavision frame info -
-**
-**     Each frame has this structure defined.
-*/
-typedef struct FrameFormat
-{
-   int OpCode;                 /* Frame opcode */
-   long Parm;                  /* contains frame number for opNEXT, opREPEAT */
-   char Rep1, Rep2;            /* Rep1 is repeat counter, Rep2 is not used */
-   int TweenRate;              /* number of tweens per frame */
-   int ChannelIndex[2];        /* -3 stop sound is this channel
-                               ** -2 modify current sound
-                               ** -1 no sound for this channel
-                               ** (all others) is an index into the sound
-                               ** list.  Which sound to use.
-                               */
-   int NumberOfPolys;          /* number of polygons in this frame */
-   int ColorPalette[32];       /* xRGB - format 4 bits per register */
-   int Pan, Tilt;              /* 0 is centered, (+-) amounts are in pixels */
-   int Modes;                  /* Frame modes */
-   int pad;                    /* expansion */
-};
-/* Fantavision polygon info -
-**
-**     Each polygon has this structure defined.
-*/
-typedef struct PolyFormat
-{
-   int NumberOfPoints;         /* how many vertexs for this polygon */
-   int Type;                   /* polygon type */
-   int Color;                  /* palette color number (see note 1) */
-   Rect Bounds;                /* enclosing rectangle of polygon */
-   int Depth;                  /* polygon view depth (see note 2) */
-   char DotModeSize;           /* in pixels, not larger than 40 */
-   char DotModeSide;           /* determines outlining features */
-   int OutlineColor;           /* palette color number for outline */
-   int BitMapIndex;            /* if not -1, then bitmap index into bitmap list */
-   int BMRealWidth;            /* in pixels */
-   int BMRealHeight;
-   int TextLength;             /* length of text for pTEXTBLOCK */
-   int TextJust;
-   char TextSize;              /* size in pixels */
-   char TextStyle;
-   long pad;                   /* expansion */
-   Point p[];                  /* array of points defining vertexs */
-};
-/* Fantavision high-level IFF format.
-**
-   FORM FANT
-       FHDR
-       - background -
-       FORM ILBM   if Background is non-zero
-           BMHD
-           BODY
-       - bitmap list -
-       NOTE:  If a bitmap has a mask, it will be compute during load time.
-       FORM ILBM   times NumberOfBitMaps
-           BMHD
-           BODY
-       - sound list -
-   {   FORM 8SVX   times NumberOfSounds
-           VHDR
-           BODY
-       SEFX    }   Default parameters for sound
-       - frame list -
-   {   FRAM        times NumberOfFrames
-       SEFX        if sound for channel 1.
-       SEFX        if sound for channel 2.
-       POLY        times NumberOfPolys
-     { CSTR        Text of poly if PolyType = pTEXTBLOCK
-       CSTR  } }   Name of font
-*/
-/******- NOTES -**********************************************************/
-/*
-** 1 - The color palette is a number from 0 to 1120.  The first 32 numbers
-**     are normal RGB colors, but the rest index into a pre-defined
-**     set of patterns.
-**
-** 2 - The view depth of each polygon determines the display order.  The
-**     higher the number the closer the polygon is to the viewer.  During
-**     editing, each polygon is assigned numbers in multiplies of 100,
-**     but to function, any number can work.
-*/</pre>
-=== Flow ===
-<pre>TITLE:  HEAD  (FORM used by Flow - New Horizons Software, Inc.)
-IFF FORM / CHUNK DESCRIPTION
-============================
-Form/Chunk ID:  FORM HEAD, Chunks NEST, TEXT, FSCC
-Date Submitted: 03/87
-Submitted by:   James Bayless - New Horizons Software, Inc.
-FORM
-====
-FORM ID:  HEAD
-FORM Description:
-   FORM HEAD is the file storage format of the Flow idea processor
-by New Horizons Software, Inc.  Currently only the TEXT and NEST
-chunks are used.  There are plans to incorporate FSCC and some
-additional chunks for headers and footers.
-CHUNKS
-======
-CHUNK ID:  NEST
-   This chunk consists of only of a word (two byte) value that gives
-the new current nesting level of the outline.  The initial nesting level
-(outermost level) is zero.  It is necessary to include a NEST chunk only
-when the nesting level changes.  Valid changes to the nesting level are
-either to decrease the current value by any amount (with a minimum of 0)
-or to increase it by one (and not more than one).
-CHUNK ID:  TEXT
-   This chunk is the actual text of a heading.  Each heading has a TEXT
-chunk (even if empty).  The text is not NULL terminated - the chunk
-size gives the length of the heading text.
-CHUNK ID: FSCC
-   This chunk gives the Font/Style/Color changes in the heading from the
-most recent TEXT chunk.  It should occur immediately after the TEXT chunk
-it modifies.  The format is identical to the FSCC chunk for the IFF
-form type 'WORD' (for compatibility), except that only the 'Location'
-and 'Style' values are used (i.e., there can be currently only be style
-changes in an outline heading).  The structure definition is:
-typedef struct {
-   UWORD   Location;   /* Char location of change */
-   UBYTE   FontNum;    /* Ignored */
-   UBYTE   Style;      /* Amiga style bits */
-   UBYTE   MiscStyle;  /* Ignored */
-   UBYTE   Color;      /* Ignored */
-   UWORD   pad;        /* Ignored */
-} FSCChange;
-   The actual chunk consists of an array of these structures, one entry
-for each Style change in the heading text.</pre>
-=== Color Lookup Table ===
-<pre>TITLE: CLUT IFF chunk proposal
-&quot;CLUT&quot; IFF 8-Bit Color Look Up Table
-Date:   July 2, 1989
-From:   Justin V. McCormick
-Status: Public Proposal
-Supporting Software:  FG 2.0 by Justin V. McCormick for PP&amp;S
-Introduction:
-  This memo describes the IFF supplement for the new chunk &quot;CLUT&quot;.
-Description:
-  A CLUT (Color Look Up Table) is a special purpose data module
-containing table with 256 8-bit entries.  Entries in this table
-can be used directly as a translation for one 8-bit value to
-another.
-Purpose:
-  To store 8-bit data look up tables in a simple format for
-later retrieval.  These tables are used to translate or bias
--bit intensity, contrast, saturation, hue, color registers, or
-other similar data in a reproducable manner.
-Specifications:
-/* Here is the IFF chunk ID macro for a CLUT chunk */
-#define ID_CLUT MakeID('C','L','U','T')
-/*
- * Defines for different flavors of 8-bit CLUTs.
- */
-#define CLUT_MONO       0L      /* A Monochrome, contrast or intensity LUT */
-#define CLUT_RED        1L      /* A LUT for reds               */
-#define CLUT_GREEN      2L      /* A LUT for greens             */
-#define CLUT_BLUE       3L      /* A LUT for blues              */
-#define CLUT_HUE        4L      /* A LUT for hues               */
-#define CLUT_SAT        5L      /* A LUT for saturations        */
-#define CLUT_UNUSED6    6L      /* How about a Signed Data flag */
-#define CLUT_UNUSED7    7L      /* Or an Assumed Negative flag  */
-/* All types &gt; 7 are reserved until formally claimed */
-#define CLUT_RESERVED_BITS 0xfffffff8L
-/* The struct for Color Look-Up-Tables of all types */
-typedef struct
-{
-  ULONG type;           /* See above type defines */
-  ULONG res0;           /* RESERVED FOR FUTURE EXPANSION */
-  UBYTE lut[256];       /* The 256 byte look up table */
-} ColorLUT;
-CLUT Example:
-  Normally, the CLUT chunk will appear after the BMHD of an FORM
-ILBM before the BODY chunk, in the same &quot;section&quot; as CMAPs are
-normally found.  However, a FORM may contain only CLUTs with no
-other supporting information.
-  As a general guideline, it is desirable to group all CLUTs
-together in a form without other chunk types between them.
-If you were using CLUTs to store RGB intensity corrections, you
-would write three CLUTs in a row, R, G, then B.
-  Here is a box diagram for a 320x200x8 image stored as an IFF ILBM
-with a single CLUT chunk for intensity mapping:
-        +-----------------------------------+
-        |'FORM'         64284               |     FORM 64284 ILBM
-        +-----------------------------------+
-        |'ILBM'                             |
-        +-----------------------------------+
-        | +-------------------------------+ |
-        | | 'BMHD'      20                | |     .BMHD 20
-        | | 320, 200, 0, 0, 8, 0, 0, ...  | |
-        | | ------------------------------+ |
-        | | 'CLUT'      264               | |     .CLUT 264
-        | | 0, 0, 0; 32, 0, 0; 64,0,0; .. | |
-        | +-------------------------------+ |
-        | +-------------------------------+ |
-        | |'BODY'               64000     | |     .BODY 64000
-        | |0, 0, 0, ...                   | |
-        | +-------------------------------+ |
-        +-----------------------------------+
-Design Notes:
--------------
-  I have deliberately kept this chunk simple (KISS) to
-facilitate implementation.  In particular, no provision is made
-for expansion to 16-bit or 32-bit tables.  My reasoning is that
-a 16-bit table can have 64K entries, and thus would benefit from
-data compression.  My suggestion would be to propose another
-chunk or FORM type better suited for large tables rather than
-small ones like CLUT.</pre>
-=== NewTek Dynamic HAM color ===
-<pre>Newtek Dynamic Ham color chunks
-Newtek for Digiview IV (dynamic Ham)
-ILBM.DYCP - dynamic color palette
-longwords (file setup stuff)
-ILBM.CTBL - array of words, one for each color (0rgb)</pre>
-=== Dots per inch ===
-<pre>ILBM DPI chunk
-==============
-Registered by:
-Spencer Shanson
-Genesta Rd
-Plumstead
-London SE18 3ES
-ENGLAND
--16-90
-ILBM.DPI   Dots Per Inch   to allow output of an image at the
-same resolution it was scanned at
-typedef struct {
-        UWORD dpi_x;
-        UWORD dpi_y;
-        } DPIHeader ;
-For example, an image scanned at horizontal resolution of
-dpi and vertical resolution of 300dpi would be saved as:
-44504920 00000004 00F0 012C
-D P I    size     dpi_x dpi_y</pre>
-=== DPaint perspective ===
-<pre>Form/Chunk ID:   Chunk DPPV  (DPaint II ILBM perspective chunk)
-Date Submitted:  12/86
-Submitted by:    Dan Silva
-Chunk Description:
-   The DPPV chunk describes the perspective state in a DPaintII ILBM.
-Chunk Spec:
-/* The chunk identifier DPPV */
-#define ID_DPPV    MakeID('D','P','P','V')
-typedef LONG LongFrac;
-typedef struct ( LongFrac x,y,z; )  LFPoint;
-typedef LongFrac  APoint[3];
-typedef union {
-   LFPoint l;
-   APoint  a;
-   } UPoint;
-/* values taken by variable rotType */
-#define ROT_EULER  0
-#define ROT_INCR   1
-/* Disk record describing Perspective state */
-typedef struct {
-   WORD     rotType;           /* rotation type */
-   WORD     iA, iB, iC;        /* rotation angles (in degrees) */
-   LongFrac Depth;             /* perspective depth */
-   WORD     uCenter, vCenter;  /* coords of center perspective,
-                                * relative to backing bitmap,
-                                * in Virtual coords
-                                */
-   WORD     fixCoord;          /* which coordinate is fixed */
-   WORD     angleStep;         /* large angle stepping amount */
-   UPoint   grid;              /* gridding spacing in X,Y,Z */
-   UPoint   gridReset;         /* where the grid goes on Reset */
-   UPoint   gridBrCenter;      /* Brush center when grid was last on,
-                                * as reference point
-                                */
-   UPoint   permBrCenter;      /* Brush center the last time the mouse
-                                * button was clicked, a rotation performed,
-                                * or motion along &quot;fixed&quot; axis
-                                */
-   LongFrac rot[3][3];         /* rotation matrix */
-   } PerspState;
-SUPPORTING SOFTWARE
-===================
-DPaint II   by Dan Silva for Electronic Arts</pre>
-=== DPaint IV enhanced color cycling ===
-<pre>Submitted by Lee Taran
-Purpose:
-Enhanced Color Cycling Capabilities
--------------------------------------
-   * DPaintIV supports a new color cycling model which does NOT
-     require that color cycles contain a contiguous range of color
-     registers.
-     For example:
-       If your range looks like:  [1][3][8][2]
-       then at each cycle tick
-          temp = [2],
-          [2] = [8],
-          [8] = [3],
-          [3] = [1],
-          [1] = temp
-   * You can now cycle a single register thru a series of rgb values.
-     For example:
-        If your range looks like: [1] [orange] [blue] [purple]
-        then at each cycle tick color register 1 will take on the
-        next color in the cycle.
-        ie:  t=0:  [1] = curpal[1]
-             t=1:  [1] = purple
-             t=2:  [1] = blue
-             t=3:  [1] = orange
-             t=4:  goto t=0
-   * You can combine rgb cycling with traditional color cycling.
-     For example:
-         Your range can look like:
-             [1] [orange] [blue] [2] [green] [yellow]
-         t=0: [1] = curpal[1], [2] = curpal[2]
-         t=1: [1] = yellow,    [2] = blue
-         t=2: [1] = green,     [2] = orange
-         t=3: [1] = curpal[2], [2] = curpal[1]
-         t=4: [1] = blue,      [2] = yellow
-         t=5: [1] = orange,    [2] = green
-         t=6: goto t=0
-Note:
-   * DPaint will save out an old style range CRNG if the range fits
-     the CRNG model otherwise it will save out a DRNG chunk.
-   * no thought has been given (yet) to interlocking cycles
-/* ---------------------------------------------------------------------
- IFF Information:  DPaintIV DRNG chunk
-          DRNG ::= &quot;DRNG&quot; # { DRange DColor* DIndex* }
- a &lt;cell&gt; is where the color or register appears within the range
- The RNG_ACTIVE flags is set when the range is cyclable. A range
- should only have the RNG_ACTIVE if it:
-&gt; contains at least one color register
-&gt; has a defined rate
-&gt; has more than one color and/or color register
- If the above conditions are met then RNG_ACTIVE is a user/program
- preference.  If the bit is NOT set the program should NOT cycle the
- range.
- The RNG_DP_RESERVED flags should always be 0!!!
- --------------------------------------------------------------------- */
-typedef struct {
-   UBYTE min;           /* min cell value */
-   UBYTE max;           /* max cell value */
-   SHORT rate;          /* color cycling rate, 16384 = 60 steps/second */
-   SHORT flags;         /* 1=RNG_ACTIVE,4=RNG_DP_RESERVED */
-   UBYTE ntrue;         /* number of DColor structs to follow */
-   UBYTE nregs;         /* number of DIndex structs to follow */
-   } DRange;
-typedef struct { UBYTE cell; UBYTE r,g,b; } DColor; /* true color cell */
-typedef struct { UBYTE cell; UBYTE index; } DIndex; /* color register cell */</pre>
-=== Encapsulated PostScript ===
-<pre>Pixelations   Kevin Saltzman   617-277-5414
-Chunk to hold encapsulated postscript
-Used by PixelScript in their clip art.  Holds a postscript
-representation of the ILBM's graphic image.
-EPSF length
-   ; Bounding box
-   WORD lowerleftx;
-   WORD lowerlefty;
-   WORD upperrightx;
-   WORD upperrighty;
-   CHAR []    ; ascii postscript file</pre>
-=== Numerical data storage ===
-<pre>Numerical data storage (MathVision - Seven Seas)
-MTRX FORM, for matrix data storage                    19-July-1990
-Submitted by: Doug Houck
-              Seven Seas Software
-              (address, etc)
-INTRODUCTION:
-Numerical data, as it comes from the real world, is an ill-mannered beast.
-Often much is assumed about the data, such as the number of dimensions,
-formatting, compression, limits, and sizes.  As such, data is not portable.
-The MTRX FORM will both store the data, and completely describe its
-format, such that programs no longer need to guess the parameters of
-a data file.  There needs to be but one program to read ascii files and
-output MTRX IFF files.
-A matrix, by our definition, is composed of three types of things.
-Firstly, the atomic data, such as an integer, or floating point number.
-Secondly, arrays, which are simply lists of things which are all the same.
-Thirdly, structures, which are lists of things which are different.
-Both arrays and structures may be composed of things besides atomic data -
-they may contain other structures and arrays as well.  This concept
-of nesting structures may be repeated to any desired depth.
-For example, a list of data pairs could be encoded as an array of structures,
-where each structure contains two numbers.  A two-dimensional array is
-simply an array of arrays.
-Since space conservation is often desirable, there is provision for
-representing each number with fewer bits, and compressing the bits together.
-CHUNKS
-The MTRX FORM is composed of the definition of the structure, followed
-by the BODY which contains the data which is defined.  Usually, there
-is only one set of data, but a smarter IFF read could use the definition
-as a PROPerty, with identically formatted data sets (BODYs) in a LIST.
-  FORM MTRX
-    definition (ARRY | STRU | DTYP)
-    BODY
-ARRY: The array chunk defines a counted list of similar items.
-The first (required) chunk in an ARRY is ELEM, which gives the number
-of elements in the array.  Optionally, there may be limits given, (LOWR
-and UPPR), which could be used in scaling during sampling of the data.
-Lastly is the definition of an element of the array, which may be a
-nested definition like everything else.
-  ARRY ::= &quot;ARRY&quot; #{ ELEM [LOWR] [UPPR] [PACK] ARRY|STRU|DTYP }
-STRU: The structure chunk defines a counted list of dissimilar things.
-The first (required) chunk in a STRU is FLDS, which gives the number
-of fields in the structure.  Lastly are definitions of each field
-in the structure.  Again, each field may have a nested definition like
-everything else.
- STRU ::= &quot;STRU&quot; #{ FLDS ([PACK] ARRY|STRU|DTYP)* }
-VALU: The value contains a datatype, and then a constant of that type.
-The datatype contains the size of the constant, so this chunk has variable
-size.  VALU is used in the ARRY chunk to give the scaling limits of the array.
-BODY: This is the actual data we went to so much effort to describe.
-It is stored in &quot;row-first&quot; format, that is, items at the bottom of the
-nested description are stored next to each other.  In most cases, it
-should be sufficient to simply block-read the whole chunk from disk,
-unless the reader needs to adjust byte-ordering or store in a more
-time-efficient format in memory.  Data is assumed to be byte-aligned.
-PACK: The PACK chunk is necessary when the bit length of the data is
-not a multiple of 8, that is, not byte-aligned, and the user wishes
-to conserve space by packing data items together.  PACK is simply a
-number - the number of items to bit-pack before aligning on a byte.
-A PACK is in effect for the remainder of its nested scope, or until
-overridden by a new specification.  A STRU or ARRY is assumed to have
-a PACK of 1 by default - it is not affected by PACKs in definitions above.
-A PACK of 0 means to byte-align before processing the next definition.
-The PACK specifier should be normalized.  For example, when packing a large
-array of 3-bit numbers, PACK should be 8 since 3*8 = 24. In this case 8 is
-the smallest PACK number which aligns on a byte naturally.
-DTYP: The DataType is the most interesting chunk, as it attempts to define
-every conceivable type of numeric data with 32 bits.  The 32 bits are broken
-down into three fields, 1) the size in bits, 2) the Class, and 3) SubClass.
-The Class makes the most major distinction, separating integers from floating
-point numbers from Binary Coded Decimal and etc.  Within each class is a
-SubClass, which gives the specific encoding used.  Finally, the Size tells
-what how much room the data occupies.  The basic division of datatypes is
-given in the tree structure below.
-Class             SubClass     Size  Final Specific Type
-=====             ========     ====  ===================
- |
-Binary Unsigned - 0 ------------ 8   UByte
- |                              16   UWord
- |                              32   ULong
- |
-Binary Signed --- 0 ------------  8  Byte
- |                               16  Word
- |                               32  ULong
- |
-Real ------------Ieee38 -------- 32  Ieee Single Precision
- |                |
- |               Ieee308 ------- 64  Double Precision
- |                |              32  Truncated Double Precision
- |                |
- |               FFP ----------- 32  Motorola Fast Floating Point
- |
-Text ----------- Text0 --------- ??  Null-terminated text
- |                |
- |               CText --------- ??  Number of characters in first byte
- |                |
- |               FText --------- ??  Fixed length, space padded
- |
-BCD ------------ Nibble -------- ??
-                  |
-                 Character ----- ??
-  A design goal was to create a classification system which other people
-can easily plug into.  Many data types are simply size variations on
-existing data types.  For example, a 4-bit integer can be specified by
-giving the size as four bits in the Signed Binary class.  Be aware that
-not all MTRX readers may support your new type, but there will not be
-any type clashes or ambiguities by following these rules.  If you have
-a truly unique Class or SubClass, you will need to register it with
-Commodore to prevent clashes.
- A second design goal was to create a format which is easily decoded
-by software.  By aligning fields on bytes, you have the option of redefining
-the datatype as a structure, so as to avoid shifting when accessing the
-fields.  Since the numbers are sequentially assigned, they are suitable
-as array indicies, and may be optimized in a C switch statement.
-A third design goal was allowing for naive and sophisticated readers.
-In checking for a certain datatype, a naive reader can simply compare
-the whole datatype with a small set of known types, which assumes that
-each different Size defines a unique datatype.  Sophisticated readers
-will consider the Class, SubClass and Size separately, so as to support
-arbitrary size integers, and truncated Floating Point numbers, for example.
- *
- * MTRX ::= &quot;FORM&quot; #{ &quot;MTRX&quot; ARRY|STRU|DTYP BODY        } Matrix
- * ARRY ::= &quot;ARRY&quot; #{ ELEM [LOWR] [UPPR] [PACK] ARRY|STRU|DTYP } Array
- * STRU ::= &quot;STRU&quot; #{ FLDS ([PACK] ARRY|STRU|DTYP)*     } Structure
- * ELEM ::= &quot;ELEM&quot; #{ elements                          } Array elements
- * LOWR ::= &quot;LOWR&quot;  { VALU                              } Minimum limit
- * UPPR ::= &quot;UPPR&quot;  { VALU                              } Maximum limit
- * VALU ::=        #{ dtyp value                        } Value (in union)
- * dtyp ::=         { size, subclass, class             } Data Type (scalar)
- * DTYP ::= &quot;DTYP&quot; #{ dtyp                              }
- * FLDS ::= &quot;FLDS&quot; #{ number of fields                  } Number of Fields
- * PACK ::= &quot;PACK&quot; #{ units packed b4 byte alignment    } Packing
- * BODY ::= &quot;BODY&quot; #{ inner-first binary dump           } Data
- *
- *   [] means optional
- *   #  means the size of the unit following
- *   *  means one or more of
- *</pre>
-=== Program traceback ===
-<pre>Program traceback (SAS Institute)
-FORM PGTB
-Proposal:
-        New IFF chunk type, to be named PGTB, meaning ProGram TraceBack.
-Format:
-        'PGTB'          - chunk identifier
-        length          - longword for length of chunk
-        'FAIL'          - subfield giving environment at time of crash
-        length          - longword length of subfield
-        NameLen         - length of program name in longwords (BSTR)
-        Name            - program name packed in longwords
-        Environment     - copy of AttnFlags field from ExecBase,
-                          gives type of processor, and existence of
-                          math chip
-        VBlankFreq      - copy of VBlankFrequency field from ExecBase
-        PowerSupFreq    - copy of PowerSupplyFrequency field from ExecBase
-                          above fields may be used to determine whether
-                          machine was PAL or NTSC
-        Starter         - non-zero = CLI, zero = WorkBench
-        GURUNum         - exception number of crash
-        SegCount        - number of segments for program
-        SegList         - copy of seglist for program
-                          (Includes all seglist pointers, paired with
-                           sizes of the segments)
-        'REGS'          - register dump subfield
-        length          - length of subfield in longwords
-        GURUAddr        - PC at time of crash
-        Flags           - copy of Condition Code Register
-        DDump           - dump of data registers
-        ADump           - dump of address registers
-        'VERS'          - revision of program which created this file
-        length          - length of subfield in longwords
-        version         - main version of writing program
-        revision        - minor revision level of writing program
-        TBNameLen       - length of name of writing program
-        TBName          - name of writing program packed in longwords (BSTR)
-        'STAK'          - stack dump subfield
-        length          - length of subfield in longwords
-        (type)          - tells type of stack subfield, which can be any of
-                          the following:
-                -----------------------------------------------------------
-                Info            - value 0
-                StackTop        - address of top of stack
-                StackPtr        - stack pointer at time of crash
-                StackLen        - number of longwords on stack
-                -----------------------------------------------------------
-                Whole stack     - value 1
-                                  only used if total stack to be dumped is 8k
-                                  or less in size
-                Stack           - dump of stack from current to top
-                -----------------------------------------------------------
-                Top 4k          - value 2
-                                  if stack used larger than 8k, this part
-                                  is a dump of the top 4k
-                Stack           - dump of stack from top - 4k to top
-                -----------------------------------------------------------
-                Bottom 4k       - value 3
-                                  if stack used larger than 8k, this part
-                                  is a dump of the bottom 4k
-                Stack           - dump of stack from current to current + 4k
-        In other words, we will dump a maximum of 8k of stack data.  This
-        does NOT mean the stack must be less than 8k in size to dump the
-        entire stack, just that the amount of stack USED be less than 8k.
-        'UDAT'          - Optional User DATa chunk.  If the user assigns
-                          a function pointer to the label &quot;_ONGURU&quot;, the
-                          catcher will call this routine prior to closing
-                          the SnapShot file, passing one parameter on the
-                          stack - an AmigaDOS file pointer to the SnapShot
-                          file.  Spec for the _ONGURU routine:
-                                void &lt;function name&gt;(fp)
-                                long fp;
-                          In other words, your routine must be of type 'void'
-                          and must take one parameter, an AmigaDOS file
-                          handle (which AmigaDOS wants to see as a LONG).
-        length          - length of the UserDATa chunk, calculated after the
-                          user routine terminates.</pre>
-=== DPaint IV perspective move ===
-<pre>/* -----------------------------------------------------------------------
-   IFF Information:
-       PRSP ::= &quot;FORM&quot; # {&quot;PSRP&quot; MOVE }
-       MOVE ::= &quot;MOVE&quot; # { MoveState  }
- * ---------------------------------------------------------------------- */
-typedef struct {
-   BYTE reserved;         /* initialize to 0 */
-   BYTE moveDir;          /* 0 = from point  1 = to point  */
-   BYTE recordDir;        /* 0 = FORWARD,    1 = STILL, 2 = BACKWARD */
-   BYTE rotationType;     /* 0 = SCREEN_RELATIVE, 1 = BRUSH_RELATIVE */
-   BYTE translationType;  /* 0 = SCREEN_RELATIVE, 1 = BRUSH_RELATIVE */
-   BYTE cyclic;           /* 0 = NO, 1 = YES */
-   SHORT distance[3];     /* x,y,z distance displacement */
-   SHORT angle[3];        /* x,y,z rotation angles */
-   SHORT nframes;         /* number of frames to move */
-   SHORT easeout;         /* number of frames to ease out */
-   SHORT easein;          /* number of frames to ease in */
-   } MoveState;</pre>
-=== RGB image ===
-<pre>FORM RGBN and FORM RGB8
------------------------
-RGBN and RGB8 files are used in Impulse's Turbo Silver and Imagine.
-They are almost identical to FORM ILBM's except for the BODY chunk
-and slight differences in the BMHD chunk.
-A CAMG chunk IS REQUIRED.
-The BMHD chunk specfies the number of bitplanes as 13 for type RGBN
-and 25 for type RGB8, and the compression type as 4.
-The FORM RGBN uses 12 bit RGB values, and the FORM RGB8 uses
-bit RGB values.
-The BODY chunk contains RGB values, a &quot;genlock&quot; bit, and repeat
-counts.  In Silver, when &quot;genlock&quot; bit is set, a &quot;zero color&quot; is
-written into the bitplanes for genlock video to show through.
-In Diamond and Light24 (Impulse 12 &amp; 24 bit paint programs),
-the genlock bit is ignored if the file is loaded as a picture
-(and the RGB color is used instead), and if the file is loaded
-as a brush the genlock bit marks pixels that are not part of
-the brush.
-For both RGBN and RGB8 body chunks, each RGB value always has a
-repeat count.  The values are written in different formats depending
-on the magnitude of the repeat count.
-For the RGBN BODY chunk:
-        For each RGB value, a WORD (16-bits) is written: with the
-RGB bits in the MSB (most significant bit) positions;
-        the &quot;genlock&quot; bit next; and then a 3 bit repeat count.
-        If the repeat count is greater than 7, the 3-bit count is
-        zero, and a BYTE repeat count follows.  If the repeat count
-        is greater than 255, the BYTE count is zero, and a WORD
-        repeat count follows.  Repeat counts greater than 65536 are
-        not supported.
-For the RGB8 body chunk:
-        For each RGB value, a LONG-word (32 bits) is written:
-        with the 24 RGB bits in the MSB positions; the &quot;genlock&quot;
-        bit next, and then a 7 bit repeat count.
-        In a previous version of this document, there appeared the
-        following line:
-        &quot;If the repeat count is greater than 127, the same rules apply
-        as in the RGBN BODY.&quot;
-        But Impulse has never written more than a 7 bit repeat count,
-        and when Imagine and Light24 were written, they didn't support
-        reading anything but 7 bit counts.
-Sample BODY code:
-                if(!count) {
-                        if (Rgb8) {
-                                fread (&amp;w, 4, 1, RGBFile);
-                                lock = w &amp; 0x00000080;
-                                rgb = w &gt;&gt; 8;
-                                count = w &amp; 0x0000007f;
-                        } else {
-                                w = (UWORD) getw (RGBFile);
-                                lock = w &amp; 8;
-                                rgb = w &gt;&gt; 4;
-                                count = w &amp; 7;
-                        }
-                        if (!count)
-                                if (!(count = (UBYTE) getc (RGBFile)))
-                                        count = (UWORD) getw (RGBFile);
-                }
-The pixels are scanned from left to right across horizontal
-lines, processing from top to bottom.  The (12 or 24 bit) RGB
-values are stored with the red bits as the MSB's, the green
-bits next, and the blue bits as the LSB's.
-Special note:  As of this writing (Sep 88), Silver does NOT
-support anything but black for color zero.</pre>
-=== Sampled sound ===
-<pre>                       IFF FORM &quot;SAMP&quot; Sampled Sound
- Date:   Dec 3,1989
- From:   Jim Fiore and Jeff Glatt, dissidents
-   The form &quot;SAMP&quot; is a file format used to store sampled sound data in some
-ways like the current standard, &quot;8SVX&quot;. Unlike &quot;8SVX&quot;, this new format is not
-restricted to 8 bit sample data. There can be more than one waveform per
-octave, and the lengths of different waveforms do not have to be factors of
-. In fact, the lengths (waveform size) and playback mapping (which musical
-notes each waveform will &quot;play&quot;) are independently determined for each wave-
-form. Furthermore, this format takes into account the MIDI sample dump stan-
-dard (the defacto standard for musical sample storage), while also incorpo-
-rating the ability to store Amiga specific info (for example, the sample data
-that might be sent to an audio channel which is modulating another channel).
-Although this form can be used to store &quot;sound effects&quot; (typically oneShot
-sounds played at a set pitch), it is primarily intended to correct the many
-deficiencies of the &quot;8SVX&quot; form in regards to musical sampling. Because the
-emphasis is on musical sampling, this format relies on the MIDI (Musical
-Instrument Digital Interface) method of describing &quot;sound events&quot; as does
-virtually all currently manufactured, musical samplers. In addition, it at-
-tempts to incorporate features found on many professional music samplers, in
-anticipation that future Amiga models will implement 16 bit sampling, and
-thus be able to achieve this level of performance. Because this format is
-more complex than &quot;8SVX&quot;, programming examples to demonstrate the use of this
-format have been included in both C and assembly. Also, a library of func-
-tions to read and write SAMP files is available, with example applications.
-  SEMANTICS: When MIDI literature talks about a sample, usually it means a
-collection of many sample points that make up what we call a &quot;wave&quot;.
-        =====SIMILARITIES AND DIFFERENCES FROM THE &quot;8SVX&quot; FORM=======
-   Like &quot;8SVX&quot;, this new format uses headers to separate the various sections
-of the sound file into chunks. Some of the chunks are exactly the same since
-there wasn't a need to improve them. The chunks that remain unchanged are as
-follows:
-   &quot;(c) &quot;
-   &quot;AUTH&quot;
-   &quot;ANNO&quot;
-  Since these properties are all described in the original &quot;8SVX&quot; document,
-please refer to that for a description of these chunks and their uses. Like
-the &quot;8SVX&quot; form, none of these chunks are required to be in a sound file.
-If they do appear, they must be padded out to an even number of bytes.
-  Furthermore, two &quot;8SVX&quot; chunks no longer exist as they have been incorpo-
-rated into the &quot;BODY&quot; chunk. They are:
-   &quot;ATAK&quot;
-   &quot;RLSE&quot;
-  Since each wave can be completely different than the other waves in the
-sound file (one wave might be middle C on a piano, and another might be a
-snare drum hit), it is necessary for each wave to have its own envelope de-
-scription, and name.
-  The major changes from the &quot;8SVX&quot; format are in the &quot;MHDR&quot;, &quot;NAME&quot;, and
-&quot;BODY&quot; chunks.
-          =================THE &quot;SAMP&quot; HEADER================
- At the very beginning of a sound file is the &quot;SAMP&quot; header. This is used to
-determine if the disk file is indeed a SAMP sound file. It's attributes are
-as follows:
-#define ID_SAMP MakeID('S','A','M','P')
-  In assembly, this looks like:
-      CNOP 0,2  ;word-align
-SAMP         dc.b  'SAMP'
-sizeOfChunks dc.l  [sizes of all subsequent chunks summed]
-             =================THE &quot;MHDR&quot; CHUNK=================
-  The required &quot;MHDR&quot; chunk immediately follows the &quot;SAMP&quot; header and consists
-of the following components:
-#define ID_MHDR MakeID('M','H','D','R')
-  /* MHDR size is dependant on the size of the imbedded PlayMap. */
-  typedef struct{
-   UBYTE NumOfWaves,      /* The number of waves in this file */
-     Format,              /* # of ORIGINAL significant bits from 8-28 */
-     Flags,               /* Various bits indicate various functions */
-     PlayMode,            /* determines play MODE of the PlayMap */
-     NumOfChans,
-     Pad,
-     PlayMap[128*4],  /* a map of which wave numbers to use for
-                          each of 128 possible Midi Notes. Default to 4 */
-   } MHDRChunk;
-   The PlayMap is an array of bytes representing wave numbers. There can be a
-total of 255 waves in a &quot;SAMP&quot; file. They are numbered from 1 to 255. A wave
-number of 0 is reserved to indicate &quot;NO WAVE&quot;. The Midi Spec 1.0 designates
-that there are 128 possible note numbers (pitches), 0 to 127. The size of an
-MHDR's PlayMap is determined by (NumOfChans * 128). For example, if NumOfChans
-= 4, then an MHDR's PlayMap is 512 bytes. There are 4 bytes in the PlayMap
-for EACH of the 128 Midi Note numbers. For example, the first 4 bytes
-in PlayMap pertain to Midi Note #0. Of those 4 bytes, the first byte is the
-wave number to play back on Amiga audio channel 0. The second byte is the
-wave number to play back on Amiga audio channel 1, etc. In this way, a single
-Midi Note Number could simultaneously trigger a sound event on each of the 4
-Amiga audio channels. If NumOfChans is 1, then the PlayMap is 128 bytes and
-each midi note has only 1 byte in the PlayMap. The first byte pertains to midi
-note #0, the second pertains to midi note #1, etc. In this case, a player
-program might elect to simply play back the PlayMap wave number on any
-available amiga audio channel. If NumOfChans = 0, then there is no imbedded
-PlayMap in the MHDR, no midi note assignments for the waves, and an application
-should play back waves on any channel at their default sampleRates.
-  In effect, the purpose of the PlayMap array is to determine which (if any)
-waves are to be played back for each of the 128 possible Midi Note Numbers.
-Usually, the MHDR's NumOfChans will be set to 4 since the Amiga has 4 audio
-channels. For the rest of this document, the NumOfChans is assumed to be 4.
-  As mentioned, there can be a total of 255 waves in a &quot;SAMP&quot; file, numbered
-from 1 to 255. A PlayMap wave number of 0 is reserved to indicate that NO WAVE
-number should be played back. Consider the following example:
-  The first 4 bytes of PlayMap are  1,3,0,200.
-  If a sample playing program receives (from the serial port or another task
-perhaps) Midi Note Number 0, the following should occur:
-) The sampler plays back wave 1 on Amiga audio channel
-     number 0 (because the first PlayMap byte is 1).
-) The sampler plays back wave 3 on Amiga audio channel
-     number 1 (because the second PlayMap byte is 3).
-) The sampler does not effect Amiga audio channel 2 in
-     any way (because the third PlayMap byte is a 0).
-) The sampler plays back wave 200 on Amiga audio channel
-     number 4 (because the fourth PlayMap byte is 200).
- (This assumes INDEPENDANT CHANNEL play MODE to be discussed later in this
-  document.)
-   All four of the PlayMap bytes could even be the same wave number. This would
-cause that wave to be output of all 4 Amiga channels simultaneously.
-  NumOfWaves is simply the number of waves in the sound file.
-  Format is the number of significant bits in every sample of a wave.
-For example, if Format = 8, then this means that the sample data is an
-bit format, and that every sample of the wave can be expressed by a single
-BYTE. (A 16 bit sample would need a WORD for every sample point).
-  Each bit of the Flags byte, when set, means the following:
-Bit #0 - File continued on another disc. This might occur if the SAMP file
-         was too large to fit on 1 floppy. The accepted practice (as incor-
-         porated by Yamaha's TX sampler and Casio's FZ-1 for example) is to
-         dump as much as possible onto one disc and set a flag to indicate
-         that more is on another disc's file. The name of the files must
-         be the related. The continuation file should have its own SAMP header
-         MHDR, and BODY chunks. This file could even have its continuation
-         bit set, etc. Never chop a sample wave in half. Always close the
-         file on 1 disc after the last wave which can be completely saved.
-         Resume with the next wave within the BODY of the continuation file.
-         Also, the NumOfWaves in each file's BODY should be the number saved
-         on that disc (not the total number in all combined disk files).
-         See the end of this document for filename conventions.
-  In C, here is how the PlayMap is used when receiving a midi note-on event:
-  MapOffset = (UBYTE) MidiNoteNumber * numOfChans;
-  /* MidiNoteNumber is the received note number (i.e. the second byte of a
-     midi note-on event. numOfChans is from the SAMP MHDR. */
-  chan0waveNum = (UBYTE) playMap[MapOffset];
-  chan1waveNum = (UBYTE) playMap[MapOffset+1];
-  chan2waveNum = (UBYTE) playMap[MapOffset+2];
-  chan3waveNum = (UBYTE) playMap[MapOffset+3];
-  if (chan0waveNum != 0)
-  { /* get the pointer to wave #1's data, determine the values
-       that need to be passed to the audio device, and play this
-       wave on Amiga audio channel #0 (if INDEPENDANT PlayMode) */
-  }
-   /* do the same with the other 3 channel's wave numbers */
-  In assembly, the &quot;MHDR&quot; structure looks like this:
-             CNOP 0,2
-MHDR        dc.b 'MHDR'
-sizeOfMHDR  dc.l [this is 6 + (NumOfChans * 128) ]
-NumOfWaves  dc.b [a byte count of the # of waves in the file]
-Format      dc.b [a byte count of the # of significant bits in a sample point]
-Flags       dc.b [bit mask]
-PlayMode    dc.b [play MODE discussed later]
-NumOfChans  dc.b [# of bytes per midi note for PlayMap]
-PlayMap     ds.b [128 x NumOfChans bytes of initialized values]
-   and a received MidiNoteNumber is interpreted as follows:
-   moveq   #0,d0
-   move.b  MidiNoteNumber,d0  ;this is the received midi note #
-   bmi.s   Illegal_Number     ;exit, as this is an illegal midi note #
-   moveq   #0,d1
-   move.b  NumOfChans,d1
-   mulu.w  d1,d0              ;MidiNoteNumber x NumOfChans
-   lea     PlayMap,a0
-   adda.l  d0,a0
-   move.b  (a0)+,chan0waveNum
-   move.b  (a0)+,chan1waveNum
-   move.b  (a0)+,chan2waveNum
-   move.b  (a0),chan3waveNum
-      tst.b   chan0waveNum
-      beq.s   Chan1
- ;Now get the address of this wave number's sample data, determine the
- ;values that need to be passed to the audio device, and output the wave's
- ;data on Amiga chan 0 (assuming INDEPENDANT PlayMode).
-Chan1 tst.b chan1waveNum
-      beq.s Chan2
- ;do the same for the other wave numbers, etc.
-    =====================THE &quot;NAME&quot; CHUNK=========================
-  #define ID_NAME MakeID('N','A','M','E')
-  If a NAME chunk is included in the file, then EVERY wave must have a name.
-Each name is NULL-terminated. The first name is for the first wave, and it
-is immediately followed by the second wave's name, etc. It is legal for a
-wave's name to be simply a NULL byte. For example, if a file contained 4
-waves and a name chunk, the chunk might look like this:
-           CNOP 0,2
-Name       dc.b 'NAME'
-sizeOfName dc.l 30
-           dc.b 'Snare Drum',0  ;wave 1
-           dc.b 'Piano 1',0     ;wave 2
-           dc.b 'Piano A4',0    ;wave 3
-           dc.b 0               ;wave 4
-           dc.b 0
-  NAME chunks should ALWAYS be padded out to an even number of bytes. (Hence
-the extra NULL byte in this example). The chunk's size should ALWAYS be even
-consequently. DO NOT USE the typical IFF method of padding a chunk out to an
-even number of bytes, but allowing an odd number size in the header.
-            ==============THE &quot;BODY&quot; CHUNK===============
- The &quot;BODY&quot; chunk is CONSIDERABLY different than the &quot;8SVX&quot; form. Like all
-chunks it has an ID.
-   #define ID_BODY MakeID('B','O','D','Y')
-Every wave has an 80 byte waveHeader, followed by its data. The waveHeader
-structure is as follows:
- typedef struct {
-   ULONG  WaveSize;        /* total # of BYTES in the wave (MUST be even) */
-   UWORD  MidiSampNum;     /* ONLY USED for Midi Dumps */
-   UBYTE  LoopType,        /* ONLY USED for Midi Dumps */
-   InsType;         /* Used for searching for a certain instrument */
-   ULONG  Period,    /* in nanoseconds at original pitch */
-   Rate,             /* # of samples per second at original pitch */
-   LoopStart,         /* an offset in BYTES (from the beginning of the
-                              of the wave) where the looping portion of the
-                              wave begins. Set to WaveSize if no loop. */
-   LoopEnd;           /* an offset in BYTES (from the beginning of the
-                              of the wave) where the looping portion of the
-                              wave ends. Set to WaveSize if no loop. */
-   UBYTE  RootNote,        /* the Midi Note # that plays back original pitch */
-   VelStart;            /* 0 = NO velocity effect, 128 =
-                                negative direction, 64 = positive
-                                direction (it must be one of these 3) */
-   UWORD VelTable[16];  /* contains 16 successive offset values
-                                in BYTES from the beginning of the wave */
-  /* The ATAK and RLSE segments contain an EGPoint[] piece-wise
-     linear envelope just like 8SVX. The structure of an EGPoint[]
-     is the same as 8SVX. See that document for details. */
-   ULONG  ATAKsize,     /* # of BYTES in subsequent ATAK envelope.
-                             If 0, then no ATAK data for this wave. */
-   RLSEsize,            /* # of BYTES in subsequent RLSE envelope
-                             If 0, then no RLSE envelope follows */
-  /* The FATK and FRLS segments contain an EGPoint[] piece-wise
-     linear envelope for filtering purposes. This is included in
-     the hope that future Amiga audio will incorporate a VCF
-     (Voltage Controlled Filter). Until then, if you are doing any
-     non-realtime digital filtering, you could store info here. */
-  sizeOfFATK,            /* # of BYTES in FATK segment */
-  sizeOfFRLS,            /* # of BYTES in FRLS segment */
-  USERsize;        /*   # of BYTES in the following data
-                              segment (not including USERtype).
-                              If zero, then no user data */
-  UWORD  USERtype;     /* See explanation below. If USERsize
-                             = 0, then ignore this. */
- /* End of the waveHeader. */
- /* The data for any ATAK, RLSE, FATK, FRLS, USER, and the actual wave
-    data for wave #1 follows in this order:
-    Now list each EGPoint[] (if any) for the VCA's (Voltage Controlled Amp)
-    attack portion.
-    Now list each EGPoint[] for the VCA's (Voltage Controlled Amp)
-    release portion.
-    List EGPoints[] (if any) for FATK.
-    List EGPoints[] if any for FRLS */
-    Now include the user data here if there is any. Just pad it out
-    to an even number of bytes and have USERsize reflect that.
-    Finally, here is the actual sample data for the wave. The size (in BYTES)
-    of this data is WaveSize. It MUST be padded out to an even number of bytes. */
- } WaveFormInfo;
- /* END OF WAVE #1 */
- /* The waveHeader and data for the next wave would now follow. It is
-    the same form as the first wave */
-  In assembly,  the BODY chunk looks like this:
-           CNOP 0,2
-BodyHEADER dc.b 'BODY'
-sizeOfBody dc.l  [total bytes in the BODY chunk not counting 8 byte header]
-   ; Now for the first wave
-WaveSize       dc.l  ;[total # of BYTES in this wave (MUST be even)]
-MidiSampNum    dc.w  ;[from Midi Sample Dump]  ; ONLY USED for Midi Dumps
-LoopType       dc.b  ;[0 or 1]                 ; ONLY USED for Midi Dumps
-InsType        dc.b  0
-Period         dc.l  ;[period in nanoseconds at original pitch]
-Rate           dc.l  ;[# of samples per second at original pitch]
-LoopStart      dc.l    ;[an offset in BYTES (from the beginning of the
-                       ; of the wave) to where the looping
-                       ; portion of the wave begins.]
-LoopEnd        dc.l    ;[an offset in BYTES (from the beginning of the
-                       ; of the wave) to where the looping
-                       ; portion of the wave ends]
-RootNote       dc.b    ;[the Midi Note # that plays back original pitch]
-VelStart       dc.b    ;[0, 64, or 128]
-VelTable       dc.w    ;[first velocity offset]
-               dc.w    ;[second velocity offset]...etc
-               ds.w 14 ;...for a TOTAL of 16 velocity offsets
-ATAKsize       dc.l  ;# of BYTES in subsequent ATAK envelope.
-                     ;If 0, then no ATAK data for this wave.
-RLSEsize       dc.l  ;# of BYTES in subsequent RLSE envelope
-                     ;If 0, then no RLSE data
-FATKsize       dc.l  ;# of BYTES in FATK segment
-FRLSsize       dc.l  ;# of BYTES in FRLS segment
-USERsize       dc.l  ;# of BYTES in the following User data
-                     ;segment (not including USERtype).
-                     ;If zero, then no user data
-USERtype       dc.w  ; See explanation below. If USERsize
-                  ; = 0, then ignore this.
-  ;Now include the EGpoints[] (data) for the ATAK if any
-  ;Now the EGpoints for the RLSE
-  ;Now the EGpoints for the FATK
-  ;Now the EGpoints for the FLSR
-  ;Now include the user data here if there is any. Just pad
-  ;it out to an even number of bytes.
-  ;After the userdata (if any) is the actual sample data for
-  ;the wave. The size (in BYTES) of this segment is WaveSize.
-  ;It MUST be padded out to an even number of bytes.
-  ; END OF WAVE #1
-      =============STRUCTURE OF AN INDIVIDUAL SAMPLE POINT=============
-   Even though the next generation of computers will probably have 16 bit
-audio, and 8 bit sampling will quickly disappear, this spec has sizes expressed
-in BYTES. (ie LoopStart, WaveSize, etc.) This is because each successive
-address in RAM is a byte to the 68000, and so calculating address offsets
-will be much easier with all sizes in BYTES. The Midi sample dump, on the
-other hand, has sizes expressed in WORDS. What this means is that if you
-have a 16 bit wave, for example, the WaveSize is the total number of BYTES,
-not WORDS, in the wave.
-  Also, there is no facility for storing a compression type. This is because
-sample data should be stored in linear format (as per the MIDI spec). Currently,
-all music samplers, regardless of their internal method of playing sample data
-must transmit and expect to receive sample dumps in a linear format. It is
-up to each device to translate the linear format into its own compression
-scheme. For example, if you are using an 8 bit compression scheme that yields
-a 14 bit linear range, you should convert each sample data BYTE to a decom-
-pressed linear WORD when you save a sound file. Set the MHDR's Format
-to 14. It is up to the application to do its own compression upon loading
-a file. The midi spec was set up this way because musical samplers need to
-pass sample data between each other, and computers (via a midi interface).
-Since there are almost as many data compression schemes on the market as
-there are musical products, it was decided that all samplers should expect
-data received over midi to be in LINEAR format. It seems logical to store it
-this way on disc as well. Therefore, any software program &quot;need not know&quot; how
-to decompress another software program's SAMP file. When 16 bit sampling is
-eventually implemented there won't be much need for compression on playback
-anyway. The continuation Flag solves the problem of disc storage as well.
-  Since the 68000 can only perform math on BYTES, WORDS, or LONGS, it has
-been decided that a sample point should be converted to one of these sizes
-when saved in SAMP as follows:
- ORIGINAL significant bits          SAMP sample point size
-BYTE
-to 16                           WORD
-to 28                          LONG
-  Furthermore, the significant bits should be left-justified since it is
-easier to perform math on the samples.
-  So, for example, an 8 bit sample point (like 8SVX) would be saved as a
-BYTE with all 8 bits being significant. The MHDR's Format = 8. No
-conversion is necessary.
-  A 12 bit sample point should be stored as a WORD with the significant bits
-being numbers 4 to 15. (i.e shift the 12-bit WORD 4 places to the left). Bits
-, 1, 2 and 3 may be zero (unless some 16-bit math was performed and you wish to
-save these results). The MHDR's Format = 12. In this way, the sample
-may be loaded and manipulated as a 16-bit wave, but when transmitted via
-midi, it can be converted back to 12 bits (rounded and shifted right by 4).
-  A 16 bit sample point would be saved as a WORD with all 16 bits being
-significant. The MHDR's Format = 16. No conversion is necessary.
-          ============== The waveHeader explained ==============
-   The WaveSize is, as stated, the number of BYTES in the wave's sample table.
-If your sample data consisted of the following 8 bit samples:
-    BYTE  100,-90,80,-60,30,35,40,-30,-35,-40,00,12,12,10
- then WaveSize = 14. (PAD THE DATA OUT TO AN EVEN NUMBER OF BYTES!)
-  The MidiSampNum is ONLY used to hold the sample number received from a MIDI
-Sample Dump. It has no bearing on where the wave should be placed in a SAMP
-file. Also, the wave numbers in the PlayMap are between 1 to 255, with 1 being
-the number of the first wave in the file. Remember that a wave number of 0 is
-reserved to mean &quot;no wave to play back&quot;. Likewise, the LoopType is only used
-to hold info from a MIDI sample dump.
-   The InsType is explained at the end of this document. Often it will be set
-to 0.
-   The RootNote is the Midi Note number that will play the wave back at it's
-original, recorded pitch. For example, consider the following excerpt of a
-PlayMap:
-  PlayMap  {2,0,0,4       /* Midi Note #0 channel assignment */
-,100,1,0     /* Midi Note #1    &quot;        &quot;  */
-,4,0,0       /* Midi Note #2    &quot;        &quot;  */
-,2,1,1...}  /* Midi Note #3    &quot;        &quot;  */
-  Notice that Midi Notes 0, 1, and 2 are all set to play wave number 4 (on
-Amiga channels 3, 0, and 1 respectively). If we set wave 4's RootNote = 1,
-then receiving Midi Note number 1 would play back wave 4 (on Amiga channel 0)
-at it's original pitch. If we receive a Midi Note number 0, then wave 4 would
-be played back on channel 3) a half step lower than it's original pitch. If we
-receive Midi Note number 2, then wave 4 would be played (on channel 1) a half
-step higher than it's original pitch. If we receive Midi Note number 3, then
-wave 4 would not be played at all because it isn't specified in the PlayMap
-bytes for Midi Note number 3.
-  The Rate is the number of samples per second of the original pitch.
-For example, if Rate = 20000, then to play the wave at it's original
-pitch, the sampling period would be:
-     (1/20000)/.279365 = .000178977
-#define AUDIO_HARDWARE_FUDGE .279365
-where .279365 is the Amiga Fudge Factor (a hardware limitation). Since the
-amiga needs to see the period in terms of microseconds, move the decimal place
-to the right 6 places and our sampling period = 179 (rounded to an integer).
-In order to play the wave at higher or lower pitches, one would need to
-&quot;transpose&quot; this period value. By specifying a higher period value, the Amiga
-will play back the samples slower, and a lower pitch will be achieved. By
-specifying a lower period value, the amiga will play back the sample faster,
-and a higher pitch will be achieved. By specifying this exact period, the wave
-will be played back exactly &quot;as it was recorded (sampled)&quot;. (&quot;This period is
-JUST RIGHT!&quot;, exclaimed GoldiLocks.) Later, a method of transposing pitch will
-be shown using a &quot;look up&quot; table of periods. This should prove to be the
-fastest way to transpose pitch, though there is nothing in the SAMP format
-that compels you to do it this way.
-  The LoopStart is a BYTE offset from the beginning of the wave to where
-the looping portion of the wave begins. For example, if SampleData points to
-the start of the wave, then SampleData + LoopStart is the start address
-of the looping portion. In 8SVX, the looping portion was referred to as
-repeatHiSamples. The data from the start of the wave up to the start of the
-looping portion is the oneShot portion of the wave. LoopEnd is a BYTE
-offset from the beginning of the wave to where the looping portion ends. This
-might be the very end of the wave in memory, or perhaps there might be still
-more data after this point. You can choose to ignore this &quot;trailing&quot; data and
-play back the two other portions of the wave just like an 8SVX file (except
-that there are no other interpolated octaves of this wave).
-  VelTable contains 16 BYTE offsets from the beginning of the wave. Each
-successive value should be greater (or equal to) the preceding value. If
-VelStart = POSITIVE (64), then for each 8 increments in Midi Velocity
-above 0, you move UP in the table, add this offset to the wave's beginning
-address (start of oneShot), and start playback at that address. Here is a
-table relating received midi note-on velocity vs. start playback address for
-POSITIVE VelStart. SamplePtr points to the beginning of the sample.
- If midi velocity = 0, then don't play a sample, this is a note off
- If midi velocity = 1 to 7, then start play at SamplePtr + VelTable[0]
- If midi velocity = 8 to 15, then start at SamplePtr + VelTable[1]
- If midi velocity = 16 to 23, then start at SamplePtr + VelTable[2]
- If midi velocity = 24 to 31, then start at SamplePtr + VelTable[3]
- If midi velocity = 32 to 39, then start at SamplePtr + VelTable[4]
- If midi velocity = 40 to 47, then start at SamplePtr + VelTable[5]
- If midi velocity = 48 to 55, then start at SamplePtr + VelTable[6]
- If midi velocity = 56 to 63, then start at SamplePtr + VelTable[7]
- If midi velocity = 64 to 71, then start at SamplePtr + VelTable[8]
- If midi velocity = 72 to 79, then start at SamplePtr + VelTable[9]
- If midi velocity = 80 to 87, then start at SamplePtr + VelTable[10]
- If midi velocity = 88 to 95, then start at SamplePtr + VelTable[11]
- If midi velocity = 96 to 103, then start at SamplePtr + VelTable[12]
- If midi velocity = 104 to 111, then start at SamplePtr + VelTable[13]
- If midi velocity = 112 to 119, then start at SamplePtr + VelTable[14]
- If midi velocity = 120 to 127, then start at SamplePtr + VelTable[15]
-We don't want to specify a scale factor and use integer division to find the
-sample start. This would not only be slow, but also, it could never be certain
-that the resulting sample would be a zero crossing if the start point is calcu-
-lated &quot;on the fly&quot;. The reason for having a table is so that the offsets can be
-be initially set on zero crossings via an editor. This way, no audio &quot;clicks&quot;
-guaranteed. This table should provide enough resolution.
-   If VelStart = NEGATIVE (128), then for each 8 increments in midi
-velocity, you start from the END of VelTable, and work backwards. Here
-is a table for NEGATIVE velocity start.
- If midi velocity = 0, then don't play a sample, this is a note off
- If midi velocity = 1 to 7, then start play at SamplePtr + VelTable[15]
- If midi velocity = 8 to 15, then start at SamplePtr + VelTable[14]
- If midi velocity = 16 to 23, then start at SamplePtr + VelTable[13]
- If midi velocity = 24 to 31, then start at SamplePtr + VelTable[12]
- If midi velocity = 32 to 39, then start at SamplePtr + VelTable[11]
- If midi velocity = 40 to 47, then start at SamplePtr + VelTable[10]
- If midi velocity = 48 to 55, then start at SamplePtr + VelTable[9]
- If midi velocity = 56 to 63, then start at SamplePtr + VelTable[8]
- If midi velocity = 64 to 71, then start at SamplePtr + VelTable[7]
- If midi velocity = 72 to 81, then start at SamplePtr + VelTable[6]
- If midi velocity = 80 to 87, then start at SamplePtr + VelTable[5]
- If midi velocity = 88 to 95, then start at SamplePtr + VelTable[4]
- If midi velocity = 96 to 103, then start at SamplePtr + VelTable[3]
- If midi velocity = 104 to 111, then start at SamplePtr + VelTable[2]
- If midi velocity = 112 to 119, then start at SamplePtr + VelTable[1]
- If midi velocity = 120 to 127, then start at SamplePtr + VelTable[0]
- In essence, increasing midi velocity starts playback &quot;farther into&quot; the wave
-for POSITIVE VelStart. Increasing midi velocity &quot;brings the start point
-back&quot; toward the beginning of the wave for NEGATIVE VelStart.
- If VelStart is set to NONE (0), then the wave's playback start should
-not be affected by the table of offsets.
- What is the use of this feature? As an example, when a snare drum is hit with
-a soft volume, its initial attack is less pronounced than when it is struck
-hard. You might record a snare being hit hard. By setting VelStart to a
-NEGATIVE value and setting up the offsets in the Table, a lower midi velocity
-will &quot;skip&quot; the beginning samples and thereby tend to soften the initial
-attack. In this way, one wave yields a true representation of its instrument
-throughout its volume range. Furthermore, stringed and plucked instruments
-(violins, guitars, pianos, etc) exhibit different attacks at different
-volumes. VelStart makes these kinds of waves more realistic via a software
-implementation. Also, an application program can allow the user to enable/
-disable this feature. See the section &quot;Making the Velocity Table&quot; for info on
-how to best choose the 16 table values.
-        =========MIDI VELOCITY vs. AMIGA CHANNEL VOLUME============
- The legal range for Midi Velocity bytes is 0 to 127. (A midi velocity of 0
- should ALWAYS be interpreted as a note off).
- The legal range for Amiga channel volume is 0 to 64. Since this is half of
- the midi range, a received midi velocity should be divided by 2 and add 1
- (but only AFTER checking for a received midi velocity of 0).
-  An example of how to implement a received midi velocity in C:
-  If ( ReceivedVelocity != 0 &amp;&amp; ReceivedVelocity &lt; 128 )
-  {   /* the velocity byte of a midi message */
-      If (velStart != 0)
-      {
-          tableEntry = ReceivedVelocity / 8;
-          If (velStart == 64)
-          {    /* Is it POSITIVE */
-               startOfWave = SamplePtr + velTable[tableEntry];
-                           /* ^where to find the sample start point */
-          }
-          If (velStart == 128)
-          {    /* Is it NEGATIVE */
-               startOfWave = SamplePtr + velTable[15 - tableEntry];
-          }
-          volume = (receivedVelocity/2 + 1;  /* playback volume */
-          /* Now playback the wave */
-      }
-  }
-  In assembly,
-  lea      SampleData,a0        ;the start addr of the sample data
-  moveq    #0,d0
-  move.b   ReceivedVelocity,d0  ;the velocity byte of a midi message
-  beq      A_NoteOff            ;If zero, branch to a routine to
-                                ;process a note-off message.
-  bmi      Illegal_Vol          ;exit if received velocity &gt; 127
-  ;---Check for velocity start feature ON, and direction
-  move.b   VelStart,d1
-  beq.s    Volume               ;skip the velocity offset routine if 0
-  bmi.s    NegativeVel          ;is it NEGATIVE? (128)
-  ;---Positive velocity offset
-  move.l   d0,d1                ;duplicate velocity
-  lsr.b    #3,d1                ;divide by 8
-  add.b    d1,d1                ;x 2 because we need to fetch a word
-  lea      VelTable,a1     ;start at table's HEAD
-  adda.l   d1,a1                ;go forward
-  move.w   (a1),d1              ;get the velocity offet
-  adda.l   d1,a0          ;where to start actual playback
-  bra.s    Volume
-NegativeVel:
-  ;---Negative velocity offset
-  move.l   d0,d1                ;duplicate velocity
-  lsr.b    #3,d1                ;divide by 8
-  add.b    d1,d1                ;x 2 because we need to fetch a word
-  lea      VelTable+30,a1  ;start at table's END
-  suba.l   d1,a1                ;go backwards
-  move.w   (a1),d1              ;get the velocity offset
-  adda.l   d1,a0          ;where to start actual playback
-  ;---Convert Midi velocity to an Amiga volume
-Volume  lsr.b    #1,d0          ;divide by 2
-        addq.b   #1,d0          ;an equivalent Amiga volume
- ;---Now a0 and d0 are the address of sample start, and volume
-     ================= AN EGpoint (envelope generator) ================
- A single EGpoint is a 6 byte structure as follows:
-EGpoint1: dc.w ;[the duration in milliseconds]
-          dc.l ;[the volume factor - fixed point, 16 bits to the left of the
-               ;decimal point and 16 to the right.]
-  The volume factor is a fixed point where 1.0 ($00010000) represents the
-  MAXIMUM volume possible. (i.e. No volume factor should exceed this value.)
-  The last EGpoint in the ATAK is always the sustain point. Each EG's volume
-  is determined from 0.0, not as a difference from the previous EG's volume.
-  I hope that this clears up the ambiguity in the original 8SVX document.
-  So, to recreate an amplifier envelope like this:
-    /\
-   /  \____
-  /        \
- /          \
- |  | |   |  |
-2  3   4
-  Stages 1, 2, and 3 would be in the ATAK data, like so:
-  ;Stage 1
-  dc.w  100       ;take 100ms
-  dc.l  $00004000 ;go to this volume
-  dc.w  100
-  dc.l  $00008000
-  dc.w  100
-  dc.l  $0000C000
-  dc.w  100
-  dc.l  $00010000 ;the &quot;peak&quot; of our attack is full volume
-  ;Stage 2
-  dc.w  100
-  dc.l  $0000C000 ;back off to this level
-  dc.l  100
-  dc.l  $00008000 ;this is where we hold (SUSTAIN) until the note is turned
-                  ;off. (We are now holding at stage 3)
-  Now the RLSE data would specify stage 4 as follows:
-  dc.w  100
-  dc.l  $00004000
-  dc.w  100
-  dc.l  $00000000 ;the volume is 0
-        ===============ADDITIONAL USER DATA SECTION=================
-  There is a provision for storing user data for each wave. This is where an
-application can store Amiga hardware info, or other, application specific info.
-The waveHeader's USERtype tells what kind of data is stored. The current
-types are:
-#define SPECIFIC 0
-#define VOLMOD   1
-#define PERMOD   2
-#define LOOPING  3
- SPECIFIC (0) - application specific data. It should be stored
-                in a format that some application can immediately
-                recognize. (i.e. a &quot;format within&quot; the SAMP format)
-                If the USERtype is SPECIFIC, and an application
-                doesn't find some sort of header that it can re-
-                cognize, it should conclude that this data was
-                put there by &quot;someone else&quot;, and ignore the data.
- VOLMOD (1) -   This data is for volume modulation of an Amiga
-                channel as described by the ADKCON register. This
-                data will be sent to the modulator channel of the
-                channel set to play the wave.
- PERMOD (2) -   This data is for period modulation of an Amiga
-                channel as described by the ADKCON register. This
-                data will be sent to the modulator channel of the
-                channel set to play the wave.
- LOOPING (3) -  This contains more looping points for the sample.
-                There are some samplers that allow more than just
-                one loop (Casio products primarily). Additional
-                looping info can be stored in this format:
-               UWORD numOfLoops;  /* number of loop points to follow */
-               ULONG StartLoop1,  /* BYTE offset from the beginning of
-                                    the sample to the start of loop1 */
-               EndLoop1,          /* BYTE offset from the beginning of
-                                    the sample to the end of loop1 */
-               StartLoop2,        /* ...etc */
-          =========Converting Midi Sample Dump to SAMP=========
-  SEMANTICS: When MIDI literature talks about a sample, usually it means a
-collection of many sample points that make up what we call &quot;a wave&quot;.
-Therefore, a Midi Sample Dump sends all the sample data that makes up ONE
-wave. A SAMP file is designed to hold up to 255 of these waves (midi dumps).
-  The Midi Sample Dump specifies playback rate only in terms of a sample
-PERIOD in nanoseconds. SAMP also expresses playback in terms of samples per
-second (frequency). The Amiga needs to see its period rounded to the nearest
-microsecond. If you take the sample period field of a Midi sample Dump (the
-th, 9th, and 10th bytes of the Dump Header LSB first) which we will call
-MidiSamplePer, and the Rate of a SAMP file, here is the relationship:
-    Rate = (1/MidiSamplePer) x 10E9
-  Also the number of samples (wave's length) in a Midi Sample Dump (the 11th,
-th, and 13th bytes of the Dump header) is expressed in WORDS. SAMP's
-WaveSize is expressed in the number of BYTES. (For the incredibly stupid),
-the relationship is:
-   WaveSize = MidiSampleLength x 2
-  A Midi sample dump's LoopStart point and LoopEnd point are also in WORDS as
-versus the SAMP equivalents expressed in BYTES.
-   A Midi sample dump's sample number can be 0 to 65535. A SAMP file can hold
-up to 255 waves, and their numbers in the playmap must be 1 to 255. (A single,
-Midi Sample Dump only sends info on one wave.) When recieving a Midi Sample
-Dump, just store the sample number (5th and 6th bytes of the Dump Header LSB
-first) in SAMP's MidiSampNum field. Then forget about this number until you
-need to send the wave back to the Midi instrument from whence it came.
-  A Midi Dump's loop type can be forward, or forward/backward. Amiga hardware
-supports forward only. You should store the Midi Dump's LoopType byte here,
-but ignore it otherwise until/unless Amiga hardware supports &quot;reading audio
-data&quot; in various ways. If so, then the looptype is as follows:
-    forward = 0, backward/forward = 1
-  A Midi Dump's sample format byte is the same as SAMP's.
-  ===================== INTERPRETING THE PLAYMODE ==========================
-  PlayMode specifies how the bytes in the PlayMap are to be interpreted.
-  Remember that a PlayMap byte of 0 means &quot;No Wave to Play&quot;.
-#define INDEPENDANT 0
-#define MULTI       1
-#define STEREO      2
-#define PAN         3
-  PlayMode types:
- INDEPENDANT (0) - The wave #s for a midi note are to be output on
-                   Amiga audio channels 0, 1, 2, and 3 respectively.
-                   If the NumOfChans is &lt; 4, then only use that many channels.
- MULTI       (1) - The first wave # (first of the PlayMap bytes) for a
-                   midi note is to be output on any free channel. The other
-                   wave numbers are ignored. If all four channels are in
-                   play, the application can decide whether to &quot;steal&quot; a
-                   channel.
- STEREO     (2) -  The first wave # (first of the PlayMap bytes) is to be
-                   output of the Left stereo jack (channel 1 or 3) and if
-                   there is a second wave number (the second of the PlayMap
-                   bytes), it is to be output the Right jack (channel 2 or 4).
-                   The other wave numbers are ignored.
- PAN        (3) -  This is just like STEREO except that the volume of wave 1
-                   should start at its initial volume (midi velocity) and
-                   fade to 0. At the same rate, wave 2 should start at 0
-                   volume and rise to wave #1's initial level. The net
-                   effect is that the waves &quot;cross&quot; from Left to Right in
-                   the stereo field. This is most effective when the wave
-                   numbers are the same. (ie the same wave) The application
-                   program should set the rate. Also, the application can
-                   reverse the stereo direction (ie Right to Left fade).
-  The most important wave # to be played back by a midi note should be the
-first of the PlayMap bytes. If the NumOfChans &gt; 1, the second PlayMap byte
-should be a defined wave number as well (even if it is deliberately set to the
-same value as the first byte). This insures that all 4 PlayModes will have some
-effect on a given SAMP file. Also, an application should allow the user to
-change the PlayMode at will. The PlayMode stored in the SAMP file is only a
-default or initial set-up condition.
-  =================== MAKING A TRANSPOSE TABLE =====================
- In order to allow a wave to playback over a range of musical notes, (+/-
-semitones), its playback rate must be raised or lowered by a set amount.
-From one semitone to the next, this set amount is by a factor of the 12th
-root of 2 (assuming a western, equal-tempered scale). Here is a table that
-shows what factor would need to be multiplied by the sampling rate in order
-to transpose the wave's pitch.
-  Pitch in relation to the Root     Multiply Rate by this amount
- -------------------------------   ------------------------------
-   DOWN 6     semitones              0.5
-   DOWN 5 1/2 semitones              0.529731547
-   DOWN 5     semitones              0.561231024
-   DOWN 4 1/2 semitones              0.594603557
-   DOWN 4     semitones              0.629960525
-   DOWN 3 1/2 semitones              0.667419927
-   DOWN 3     semitones              0.707106781
-   DOWN 2 1/2 semitones              0.749153538
-   DOWN 2     semitones              0.793700526
-   DOWN 1 1/2 semitones              0.840896415
-   DOWN 1     semitones              0.890898718
-   DOWN 1/2   semitone               0.943874312
-ORIGINAL_PITCH                       1.0           /* rootnote's pitch */
-   UP   1/2   semitone               1.059463094
-   UP   1     semitones              1.122562048
-   UP   1 1/2 semitones              1.189207115
-   UP   2     semitones              1.259921050
-   UP   2 1/2 semitones              1.334839854
-   UP   3     semitones              1.414213562
-   UP   3 1/2 semitones              1.498307077
-   UP   4     semitones              1.587401052
-   UP   4 1/2 semitones              1.681792830
-   UP   5     semitones              1.781797436
-   UP   5 1/2 semitones              1.887748625
-   UP   6     semitones              2
-  For example, if the wave's Rate is 18000 hz, and you wish to play
-the wave UP 1 semitone, then the playback rate is:
-x 1.122562048 = 20206.11686 hz
-  The sampling period for the Amiga is therefore:
-     (1/20206.11686)/.279365 = .000177151
- and to send it to the Audio Device, it is rounded and expressed in micro-
-seconds: 177
-  Obviously, this involves floating point math which can be time consuming
-and impractical for outputing sound in real-time. A better method is to con-
-struct a transpose table that contains the actual periods already calculated
-for every semitone. The drawback of this method is that you need a table for
-EVERY DIFFERENT Rate in the SAMP file. If all the Rates in the
-file happened to be the same, then only one table would be needed. Let's
-assume that this is the case, and that the Rate = 18000 hz. Here is a
-table containing enough entries to transpose the waves +/- 6 semitones.
-  Pitch in relation to the Root     The Amiga Period (assuming rate = 18000 hz)
- -------------------------------   ------------------------------
-Transposition_table[TRANS_TABLE_SIZE]={
-/* DOWN 6     semitones  */            398,
-/* DOWN 5 1/2 semitones  */            375,
-/* DOWN 5     semitones  */            354,
-/* DOWN 4 1/2 semitones  */            334,
-/* DOWN 4     semitones  */            316,
-/* DOWN 3 1/2 semitones  */            298,
-/* DOWN 3     semitones  */            281,
-/* DOWN 2 1/2 semitones  */            265,
-/* DOWN 2     semitones  */            251,
-/* DOWN 1 1/2 semitones  */            236,
-/* DOWN 1     semitones  */            223,
-/* DOWN 1/2   semitone   */            211,
-/* ORIGINAL_PITCH        */            199,      /* rootnote's pitch */
-/* UP   1/2   semitone   */            187,
-/* UP   1     semitones  */            177,
-/* UP   1 1/2 semitones  */            167,
-/* UP   2     semitones  */            157,
-/* UP   2 1/2 semitones  */            148,
-/* UP   3     semitones  */            141,
-/* UP   3 1/2 semitones  */            133,
- /* Since the minimum Amiga period = 127 the following
-    are actually out of range. */
-/* UP   4     semitones  */            125,
-/* UP   4 1/2 semitones  */            118,
-/* UP   5     semitones  */            112,
-/* UP   5 1/2 semitones  */            105,
-/* UP   6     semitones  */            99   };
-  Let's assume that (according to the PlayMap) midi note #40 is set to play
-wave number 3. Upon examining wave 3's structure, we discover that the
-Rate = 18000, and the RootNote = 38. Here is how the Amiga sampling
-period is calulated using the above 18000hz &quot;transpose chart&quot; in C:
-  /* MidiNoteNumber is the received midi note's number (here 40) */
-  #define ORIGINAL_PITCH     TRANS_TABLE_SIZE/2 + 1
-/* TRANS_TABLE_SIZE is the number of entries in the transposition table
-   (dynamic, ie this can change with the application) */
-  transposeAmount = (LONG) (MidiNoteNumber - rootNote); /* make it a SIGNED LONG */
-  amigaPeriod     = Transposition_table[ORIGINAL_PITCH + transposeAmount];
-  In assembly, the 18000hz transpose chart and above example would be:
-Table       dc.w  398
-            dc.w  375
-            dc.w  354
-            dc.w  334
-            dc.w  316
-            dc.w  298
-            dc.w  281
-            dc.w  265
-            dc.w  251
-            dc.w  236
-            dc.w  223
-            dc.w  211
-ORIGINAL_PITCH  dc.w  199   ; rootnote's pitch
-            dc.w  187
-            dc.w  177
-            dc.w  167
-            dc.w  157
-            dc.w  148
-            dc.w  141
-            dc.w  133
- ; Since the minimum Amiga period = 127, the following
- ; are actually out of range.
-            dc.w  125
-            dc.w  118
-            dc.w  112
-            dc.w  105
-            dc.w  99
-  lea     ORIGINAL_PITCH,a0
-  move.b  MidiNoteNumber,d0  ;the received note number
-  sub.b   RootNote,d0        ;subtract the wave's root note
-  ext.w   d0
-  ext.l   d0                 ;make it a signed LONG
-  add.l   d0,d0              ;x 2 in order to fetch a WORD
-  adda.l  d0,a0
-  move.w  (a0),d0            ;the Amiga Period (WORD)
-  Note that these examples don't check to see if the transpose amount is
-beyond the number of entries in the transpose table. Nor do they check if
-the periods in the table are out of range of the Amiga hardware.
-    ===================== MAKING THE VELOCITY TABLE ======================
-  The 16 entries in the velocity table should be within the oneShot portion of
-the sample (ie not in the looping portion). THe first offset, VelTable[0]
-should be set to zero (in order to play back from the beginning of the data).
-The subsequent values should be increasing numbers. If you are using a graphic
-editor, try choosing offsets that will keep you within the initial attack
-portion of the wave. In practice, these values will be relatively close
-together within the wave. Always set the offsets so that when they are added
-to the sample start point, the resulting address points to a sample value of
-zero (a zero crossing point). This will eliminate pops and clicks at the
-beginning of the playback.
-  In addition, the start of the wave should be on a sample with a value of
-zero. The last sample of the oneShot portion and the first sample of the
-looping portion should be approximately equal, (or zero points). The same is
-true of the first and last samples of the looping portion. Finally, try to
-keep the slopes of the end of the oneShot, the beginning of the looping, and
-the end of the looping section, approximately equal. All this will eliminate
-noise on the audio output and provide &quot;seamless&quot; looping.
-  ======================== THE INSTRUMENT TYPE ==========================
-  Many SMUS players search for certain instruments by name. Not only is this
-slow (comparing strings), but if the exact name can't be found, then it is
-very difficult and time-consuming to search for a suitable replacement. For
-this reason, many SMUS players resort to &quot;default&quot; instruments even if these
-are nothing like the desired instruments. The InsType byte in each
-waveHeader is meant to be a numeric code which will tell an SMUS player
-exactly what the instrument is. In this way, the SMUS player can search for
-the correct &quot;type&quot; of instrument if it can't find the desired name. The type
-byte is divided into 2 nibbles (4 bits for you C programmers) with the low
-bits representing the instrument &quot;family&quot; as follows:
-= STRING, 2 = WOODWIND, 3 = KEYBOARD, 4 = GUITAR, 5 = VOICE, 6 = DRUM1,
-= DRUM2,  8 = PERCUSSION1, 9 = BRASS1, A = BRASS2, B = CYMBAL, C = EFFECT1,
- D = EFFECT2, E = SYNTH, F is undefined at this time
- Now, the high nibble describes the particular type within that family.
- For the STRING family, the high nibble is as follows:
-= VIOLIN BOW, 2 = VIOLIN PLUCK, 3 = VIOLIN GLISSANDO, 4 = VIOLIN TREMULO,
-= VIOLA BOW, 6 = VIOLA PLUCK, 7 = VIOLA GLIS, 8 = VIOLA TREM, 9 = CELLO
- BOW, A = CELLO PLUCK, B = CELLO GLIS, C = CELLO TREM, D = BASS BOW, E =
- BASS PLUCK (jazz bass), F = BASS TREM
- For the BRASS1 family, the high nibble is as follows:
-= BARITONE SAX, 2 = BARI GROWL, 3 = TENOR SAX, 4 = TENOR GROWL, 5 = ALTO
- SAX, 6 = ALTO GROWL, 7 = SOPRANO SAX, 8 = SOPRANO GROWL, 9 = TRUMPET, A =
- MUTED TRUMPET, B = TRUMPET DROP, C = TROMBONE, D = TROMBONE SLIDE, E =
- TROMBONE MUTE
- For the BRASS2 family, the high nibble is as follows:
-= FRENCH HORN, 2 = TUBA, 3 = FLUGAL HORN, 4 = ENGLISH HORN
- For the WOODWIND family, the high nibble is as follows:
-= CLARINET, 2 = FLUTE, 3 = PAN FLUTE, 4 = OBOE, 5 = PICCOLO, 6 = RECORDER,
-= BASSOON, 8 = BASS CLARINET, 9 = HARMONICA
- For the KEYBOARD family, the high nibble is as follows:
-= GRAND PIANO, 2 = ELEC. PIANO, 3 = HONKYTONK PIANO, 4 = TOY PIANO, 5 =
- HARPSICHORD, 6 = CLAVINET, 7 = PIPE ORGAN, 8 = HAMMOND B-3, 9 = FARFISA
- ORGAN, A = HARP
- For the DRUM1 family, the high nibble is as follows:
-= KICK, 2 = SNARE, 3 = TOM, 4 = TIMBALES, 5 = CONGA HIT, 6 = CONGA SLAP,
-= BRUSH SNARE, 8 = ELEC SNARE, 9 = ELEC KICK, A = ELEC TOM, B = RIMSHOT,
- C = CROSS STICK, D = BONGO, E = STEEL DRUM, F = DOUBLE TOM
- For the DRUM2 family, the high nibble is as follows:
-= TIMPANI, 2 = TIMPANI ROLL, 3 = LOG DRUM
- For the PERCUSSION1 family, the high nibble is as follows:
-= BLOCK, 2 = COWBELL, 3 = TRIANGLE, 4 = TAMBOURINE, 5 = WHISTLE, 6 =
- MARACAS, 7 = BELL, 8 = VIBES, 9 = MARIMBA, A = XYLOPHONE, B = TUBULAR BELLS,
- C = GLOCKENSPEIL
- For the CYMBAL family, the high nibble is as follows:
-= CLOSED HIHAT, 2 = OPEN HIHAT, 3 = STEP HIHAT, 4 = RIDE, 5 = BELL CYMBAL,
-= CRASH, 7 = CHOKE CRASH, 8 = GONG, 9 = BELL TREE, A = CYMBAL ROLL
- For the GUITAR family, the high nibble is as follows:
-= ELECTRIC, 2 = MUTED ELECTRIC, 3 = DISTORTED, 4 = ACOUSTIC, 5 = 12-STRING,
-= NYLON STRING, 7 = POWER CHORD, 8 = HARMONICS, 9 = CHORD STRUM, A = BANJO,
- B = ELEC. BASS, C = SLAPPED BASS, D = POPPED BASS, E = SITAR, F = MANDOLIN
- (Note that an acoustic picked bass is found in the STRINGS - Bass Pluck)
- For the VOICE family, the high nibble is as follows:
-= MALE AHH, 2 = FEMALE AHH, 3 = MALE OOO, 4 = FEMALE OOO, 5 = FEMALE
- BREATHY, 6 = LAUGH, 7 = WHISTLE
- For the EFFECTS1 family, the high nibble is as follows:
-= EXPLOSION, 2 = GUNSHOT, 3 = CREAKING DOOR OPEN, 4 = DOOR SLAM, 5 = DOOR
- CLOSE, 6 = SPACEGUN, 7 = JET ENGINE, 8 = PROPELLER, 9 = HELOCOPTER, A =
- BROKEN GLASS, B = THUNDER, C = RAIN, D = BIRDS, E = JUNGLE NOISES, F =
- FOOTSTEP
- For the EFFECTS2 family, the high nibble is as follows:
-= MACHINE GUN, 2 = TELEPHONE, 3 = DOG BARK, 4 = DOG GROWL, 5 = BOAT
- WHISTLE, 6 = OCEAN, 7 = WIND, 8 = CROWD BOOS, 9 = APPLAUSE, A = ROARING
- CROWDS, B = SCREAM, C = SWORD CLASH, D = AVALANCE, E = BOUNCING BALL,
- F = BALL AGAINST BAT OR CLUB
- For the SYNTH family, the high nibble is as follows:
-= STRINGS, 2 = SQUARE, 3 = SAWTOOTH, 4 = TRIANGLE, 5 = SINE, 6 = NOISE
-  So, for example if a wave's type byte was 0x26, this would be a SNARE DRUM.
-If a wave's type byte is 0, then this means &quot;UNKNOWN&quot; instrument.
-  ===================== THE ORDER OF THE CHUNKS =========================
- The SAMP header obviously must be first in the file, followed by the MHDR
-chunk. After this, the ANNO, (c), AUTH and NAME chunks may follow in any
-order, though none of these need appear in the file at all. The BODY chunk
-must be last.
-        ================= FILENAME CONVENTIONS =================
-   For when it becomes necessary to split a SAMP file between floppies using
-the Continuation feature, the filenames should be related. The method is the
-following:
-   The &quot;root&quot; file has the name that the user chose to save under. Subsequent
-files have an ascii number appended to the name to indicate what sublevel the
-file is in. In this way, a program can reload the files in the proper order.
-   For example, if a user saved a file called &quot;Gurgle&quot;, the first continuation
-file should be named &quot;Gurgle1&quot;, etc.
-  ============ WHY DOES ANYONE NEED SUCH A COMPLICATED FILE? ==============
-                 (or &quot;What's wrong with 8SVX anyway?&quot;)
-  In a nutshell, 8SVX is not adequate for professional music sampling. First
-of all, it is nearly impossible to use multi-sampling (utilizing several,
-different samples of any instrument throughout its musical range). This very
-reason alone makes it impossible to realistically reproduce a musical in-
-strument, as none in existance (aside from an electronic organ) uses inter-
-polations of a single wave to create its musical note range.
-  Also, stretching a sample out over an entire octave range does grotesque
-(and VERY unmusical) things to such elements as the overtone structure,
-wind/percussive noises, the instrument's amplitude envelope, etc. The 8SVX
-format is designed to stretch the playback in exactly this manner.
-SVX ignores MIDI which is the de facto standard of musical data transmission.
-SVX does not allow storing data for features that are commonplace to pro-
-fessional music samplers. Such features are: velocity sample start, separate
-filter and envelopes for each sample, separate sampling rates, and various
-playback modes like stereo sampling and panning.
-  SAMP attempts to remedy all of these problems with a format that can be
-used by a program that simulates these professional features in software. The
-format was inspired by the capabilities of the following musical products:
-  EMU's                 EMAX, EMULATOR
-  SEQUENTIAL CIRCUIT's  PROPHET 2000, STUDIO 440
-  ENSONIQ's             MIRAGE
-  CASIO's               FZ-1
-  OBERHEIM's            DPX
-  YAMAHA                TX series
-   So why does the Amiga need the SAMP format? Because professional musician's
-are buying computers. With the firm establishment of MIDI, musician's are
-buying and using a variety of sequencers, patch editors, and scoring programs.
-It is now common knowledge amoung professional musicians that the Amiga
-lags far behind IBM clones, Macintosh, and Atari ST computers in both music
-software and hardware support. Both Commodore and the current crop of short-
-sighted 3rd party Amiga developers are pigeon-holing the Amiga as &quot;a video
-computer&quot;. It is important for music software to exploit whatever capabili-
-ties the Amiga offers before the paint and animation programs, genlocks,
-frame-grabbers, and video breadboxes are the only applications selling
-for the Amiga. Hopefully, this format, with the SAMP disk I/O library will
-make it possible for Amiga software to attain the level of professionalism
-that the other machines now boast, and the Amiga lacks.</pre>
-=== 3-D rendering data ===
-<pre>FORM TDDD is used by Impulse's Turbo Silver 3.0 for 3D rendering
-data.  TDDD stands for &quot;3D data description&quot;.  The files contain
-object and (optionally) observer data.
-Turbo Silver's successor, &quot;Imagine&quot;, uses an upgraded FORM TDDD
-when it reads/writes object data.
-Currently, in &quot;standard IFF&quot; terms, a FORM TDDD has only two chunk
-types:  an INFO chunk describing observer data;  and an OBJ chunk
-describing an object heirarchy.  The INFO chunk appears only in
-Turbo Silver's &quot;cell&quot; files, and the OBJ chunk appears in both
-&quot;cell&quot; files and &quot;object&quot; files.
-The FORM has an (optional) INFO chunk followed by some number of
-OBJ chunks.  (Note:  OBJ is followed by a space -- ckID = &quot;OBJ &quot;)
-The INFO and OBJ chunks, in turn, are made up of smaller chunks with
-the standard IFF structure:  &lt;ID&gt; &lt;data-size&gt; &lt;data&gt;.
-The INFO &quot;sub-chunks&quot; are relatively straightforward to interpret.
-The OBJ &quot;sub-chunks&quot; support object heirarchies, and are slightly
-more difficult to interpret.  Currently, there are 3 types of OBJ
-sub-chunks:  an EXTR chunk, describing an &quot;external&quot; object in a
-seperate file; a DESC chunk, describing one node of a heirarchy;
-and a TOBJ chunk marking the end of a heirarchy chain.  For each
-DESC chunk, there must be a corresponding TOBJ chunk.  And an
-EXTR chunk is equivalent to a DESC/TOBJ pair.
-In Turbo Silver and Imagine, the structure of the object heirarchy
-is as follows.  There is a head object, and its (sexist) brothers.
-Each brother may have child objects.  The children may have
-grandchildren, and so on. The brother nodes are kept in a doubly
-linked list, and each node has a (possibly NULL) pointer to a
-doubly linked &quot;child&quot; list. The children point to the &quot;grandchildren&quot;
-lists, and so on.  (In addition, each node has a &quot;back&quot; pointer to
-its parent).
-Each of the &quot;head&quot; brothers is written in a seperate OBJ chunk,
-along with all its descendants.  The descendant heirarchy is
-supported as follows:
-    for each node of a doubly linked list,
-)  A DESC chunk is written, describing its object.
-)  If it has children, steps 1) to 3) are performed
-            for each child.
-)  A TOBJ chunk is written, marking the end of the children.
-For &quot;external&quot; objects, steps 1) to 3) are not performed, but
-an EXTR chunk is written instead.  (This means that an external
-object cannot have children unless they are stored in the same
-&quot;external&quot; file).
-The TOBJ sub-chunks have zero size -- and no data.  The DESC
-and EXTR sub-chunks are made up of &quot;sub-sub-chunks&quot;, again,
-with the standard IFF structure:  &lt;ID&gt; &lt;data-size&gt; &lt;data&gt;.
-( &quot;External&quot; objects were used by Turbo Silver to allow a its
-&quot;cell&quot; data files to refer to an &quot;object&quot; data file that is
-&quot;external&quot; to the cell file.  Imagine abandons the idea of
-individual cell files, and deals only in TDDD &quot;object&quot; files.
-Currently, Imagine does not support EXTR chunks in TDD files.)
-Reader software WILL FOLLOW the standard IFF procedure of
-skipping over any un-recognized chunks -- and &quot;sub-chunks&quot;
-or &quot;sub-sub-chunks&quot;. The &lt;data-size&gt; field indicates how many
-bytes to skip.  In addition it WILL OBSERVE the IFF rule that
-an odd &lt;data-size&gt; may appear, in which case the corredponding
-&lt;data&gt; field will be padded at the end with one extra byte to
-give it an even size.
-Now, on with the details.
-First, there are several numerical fields appearing in the data,
-describing object positions, rotation angles, scaling factors, etc.
-They are stored as &quot;32-bit fractional&quot; numbers, such that the true
-number is the 32-bit number divided by 65536.  So as an example,
-the number 3.14159 is stored as (hexadecimal) $0003243F.  This
-allows the data to be independant of any particular floating point
-format. And it (actually) is the internal format used in the
-&quot;integer&quot; version of Turbo Silver.  Numbers stored in this format
-are called as &quot;FRACT&quot;s below.
-Second, there are several color (or RGB) fields in the data.
-They are always stored as three UBYTEs representing the red,
-green and blue components of the color.  Red is always first,
-followed by green, and then blue.  For some of the data chunks,
-Turbo Silver reads the color field into the 24 LSB's of a
-LONGword.  In such cases, the 3 RGB bytes are preceded by a
-zero byte in the file.
-The following &quot;typedef&quot;s are used below:
-typedef LONG    FRACT;                /* 4 bytes */
-typedef UBYTE   COLOR[3];             /* 3 bytes */
-typedef struct vectors {
-    FRACT X;          /* 4 bytes */
-    FRACT Y;          /* 4 bytes */
-    FRACT Z;          /* 4 bytes */
-} VECTOR;             /* 12 bytes total */
-typedef struct matrices {
-    VECTOR I;         /* 12 bytes */
-    VECTOR J;         /* 12 bytes */
-    VECTOR K;         /* 12 bytes */
-} MATRIX;             /* 36 bytes total */
-typedef struct _tform {
-    VECTOR r;         /* 12 bytes - position */
-    VECTOR a;         /* 12 bytes - x axis */
-    VECTOR b;         /* 12 bytes - y axis */
-    VECTOR c;         /* 12 bytes - z axis */
-    VECTOR s;         /* 12 bytes - size */
-} TFORM;              /*  60 bytes total */
-The following structure is used in generating animated cells
-from a single cell.  It can be attached to an object or to the
-camera.  It is also used for Turbo Silver's &quot;extrude along a
-path&quot; feature.  (It is ignored &amp; forgotten by Imagine)
-typedef struct story {
-    UBYTE  Path[18];  /* 18 bytes */
-    VECTOR Translate; /* 12 bytes */
-    VECTOR Rotate;    /* 12 bytes */
-    VECTOR Scale;     /* 12 bytes */
-    UWORD  info;      /*  2 bytes */
-} STORY;              /* 56 bytes total */
-The Path[] name refers to a named object in the cell data.
-The path object should be a sequence of points connected
-with edges.  The object moves from the first point of the
-first edge, to the last point of the last edge.  The edge
-ordering is important.  The path is interpolated so that
-the object always moves an equal distance in each frame of
-the animation.  If there is no path the Path[] field should
-be set to zeros.
-The Translate vector is not currently used.
-The Rotate &quot;vector&quot; specifies rotation angles about the
-X, Y, and Z axes.
-The Scale vector specfies X,Y, and Z scale factors.
-The &quot;info&quot; word is a bunch of bit flags:
-    ABS_TRA    0x0001    - translate in world coorinates (not used)
-    ABS_ROT    0x0002    - rotation in world coorinates
-    ABS_SCL    0x0004    - scaling in world coorinates
-    LOC_TRA    0x0010    - translate in local coorinates (not used)
-    LOC_ROT    0x0020    - rotation in local coorinates
-    LOC_SCL    0x0040    - scaling in local coorinates
-    X_ALIGN    0x0100    - (not used)
-    Y_ALIGN    0x0200    - align Y axis to path's direction
-    Z_ALIGN    0x0400    - (not used)
-    FOLLOW_ME  0x1000    - children follow parent on path
-DESC sub-sub-chunks
--------------------
-NAME - size 18
-    BYTE    Name[18];       ; a name for the object.
-    Used for camera tracking, specifying story paths, etc.
-SHAP - size 4
-    WORD    Shape;          ; number indicating object type
-    WORD    Lamp;           ; number indicating lamp type
-    Lamp numbers are composed of several bit fields:
-        Bits 0-1:
-- not a lamp
-- like sunlight
-- like a lamp - intensity falls off with distance.
-- unused/reserved
-        Bits 2:
-- non-shadow-casting light
-- shadow-casting light
-        Bits 3-4:
-- Spherical light source
-- Cylindrical light source.
-- Conical light source.
-- unused/reserved
-    Shape numbers are:
-- Sphere
-- Stencil         ; not supported by Imagine
-- Axis            ; custom objects with points/triangles
-- Facets          ; illegal - for internal use only
-- Surface         ; not supported by Imagine
-- Ground
-    Spheres have thier radius set by the X size parameter.
-    Stencils and surfaces are plane-parallelograms, with one
-    point at the object's position vector; one side lying along
-    the object's X axis with a length set by the X size; and
-    another side starting from the position vector and going
-    &quot;Y size&quot; units in the Y direction and &quot;Z size&quot; units in
-    the X direction.  A ground object is an infinte plane
-    perpendicular to the world Z axis.  Its Z coordinate sets
-    its height, and the X and Y coordinates are only relevant
-    to the position of the &quot;hot point&quot; used in selecting the
-    object in the editor.  Custom objects have points, edges
-    and triangles associated with them.  The size fields are
-    relevant only for drawing the object axes in the editor.
-    Shape number 3 is used internally for triangles of custom
-    objects, and should never appear in a data file.
-POSI - size 12
-    VECTOR  Position;       ; the object's position.
-    Legal coordinates are in the range -32768 to 32767 and 65535/65536.
-    Currently, the ray-tracer only sees objects in the -1024 to 1024
-    range.  Light sources, and the camera may be placed outside that
-    range, however.
-AXIS - size 36
-    VECTOR  XAxis;
-    VECTOR  YAxis;
-    VECTOR  ZAxis;
-    These are direction vectors for the object coordinate system.
-    They must be &quot;orthogonal unit vectors&quot; - i.e. the sum of the
-    squares of the vevtor components must equal one (or close to it),
-    and the vectors must be perpendicular.
-SIZE - size 12
-    VECTOR  Size;
-    See SHAP chunk above.  The sizes are used in a variety of ways
-    depending on the object shape.  For custom objects, they are
-    the lengths of the coordinate axes drawn in the editor.  If the
-    object has its &quot;Quickdraw&quot; flag set, the axes lengths are also
-    used to set the size of a rectangular solid that is drawn rather
-    than drawing all the points and edges.
-PNTS - size 2 + 12 * point count
-    UWORD   PCount;         ; point count
-    VECTOR  Points[];       ; points
-    This chunk has all the points for custom objects.  The are
-    refered to by thier position in the array.
-EDGE - size 4 + 4 * edge cout
-    UWORD   ECount;         ; edge count
-    UWORD   Edges[][2];     ; edges
-    This chunk contins the edge list for custom objects.
-    The Edges[][2] array is pairs of point numbers that
-    are connected by the edges.  Edges are refered to by thier
-    position in the Edges[] array.
-FACE - size 2 + 6 * face count
-    UWORD   TCount;         ; face count
-    UWORD   Connects[][3];  ; faces
-    This chunk contains the triangle (face) list for custom objects.
-    The Connects[][3] array is triples of edge numbers that are
-    connected by triangles.
-PTHD - size 2 + 6 * axis count - Imagine only
-    UWORD   ACount;         ; axis count
-    TFORM   PData[][3];     ; axis data
-    This chunk contains the axis data for Imagine &quot;path&quot; objects.
-    The PData array contains a TFORM structure for each point along
-    the path.  The &quot;Y size&quot; item for the last point on the path tells
-    whether the path is closed or not.  Zero means closed, non-zero
-    means open.  Otherwise the Y size field is the distance along
-    the path to the next path point/axis.
-COLR - size 4
-REFL - size 4
-TRAN - size 4
-SPC1 - size 4 - Imagine only
-    BYTE    pad;            ; pad byte - must be zero
-    COLOR   col;            ; RGB color
-    These are the main object RGB color, and reflection, transmission
-    and specularity coefficients.
-CLST - size 2 + 3 * count
-RLST - size 2 + 3 * count
-TLST - size 2 + 3 * count
-    UWORD   count;          ; count of colors
-    COLOR   colors[];       ; colors
-    These are the color, reflection and transmission coefficients
-    for each face in custom objects. The count should match the
-    face count in the FACE chunk. The ordering corresponds to the
-    face order.
-TPAR - size 64 - not written by Imagine - see TXT1 below
-    FRACT   Params[16];     ; texture parameters
-    This is the list of parameters for texture modules when
-    texture mapping is used.
-TXT1 - variable size - Imagine only
-    This chunk contains texture data when texture mapping is used.
-    UWORD   Flags;          ; texture flags:
-                            ;    1 - TXTR_CHILDREN - apply to child objs
-    TFORM   TForm;          ; local coordinates of texture axes.
-    FRACT   Params[16];     ; texture parameters
-    UBYTE   PFlags[16];     ; parameter flags (currently unused)
-    UBYTE   Length;         ; length of texture file name
-    UBYTE   Name[Length];   ; texture file name (not NULL terminated)
-    UBYTE   pad;            ; (if necessary to make an even length)
-BRS1 - variable size - Imagine only (version 1.0)
-BRS2 - variable size - Imagine only (version 1.1)
-    UWORD   Flags;          ; brush type:
-                            ;    0 - Color
-                            ;    1 - Reflection
-                            ;    2 - Filter
-                            ;    3 - Altitude
-    UWORD   WFlags;         ; brush wrapping flags:
-                            ;    1   WRAP_X        - wrap type
-                            ;    2   WRAP_Z        - wrap type
-                            ;    4   WRAP_CHILDREN - apply to children
-                            ;    8   WRAP_REPEAT   - repeating brush
-                            ;    16  WRAP_FLIP     - flip with repeats
-    TFORM   TForm;          ; local coordinates of brush axes.
-    (UWORD   FullScale;)    ; full scale value
-    (UWORD   MaxSeq;)       ; highest number for sequenced brushes
-    UBYTE   Length;         ; length of brush file name
-    UBYTE   Name[Length];   ; brush file name (not NULL terminated)
-    UBYTE   pad;            ; (if necessary to make an even length)
-    The FullScale and MaxSeq items are in BRS2 chunks only.
-SURF - size 5 - not written by Imagine
-    BYTE    SProps[5];      ; object properties
-    This chunk contains object (surface) properties used
-    by Turbo Silver.
-    SProps[0] - PRP_SURFACE ; surface type
-                            ;   0 - normal
-                            ;   4 - genlock
-                            ;   5 - IFF brush
-    SProps[1] - PRP_BRUSH   ; brush number (if IFF mapped)
-    SProps[2] - PRP_WRAP    ; IFF brush wrapping type
-                            ;   0 - no wrapping
-                            ;   1 - wrap X
-                            ;   2 - wrap Z
-                            ;   3 - wrap X and Z
-    SProps[3] - PRP_STENCIL ; stencil number for stencil objects
-    SProps[4] - PRP_TEXTURE ; texture number if texture mapped
-MTTR - size 2 - not written by Imagine - see PRP1 chunk.
-    UBYTE   Type;           ; refraction type (0-4)
-    UBYTE   Index;          ; custom index of refraction
-    This chunk contains refraction data for transparent or
-    glossy objects.  If the refraction type is 4, the object
-    has a &quot;custom&quot; refractive index stored in the Index field.
-    The Index field is 100 * (true index of refraction - 1.00)
-    -- so it must be in the range of 1.00 to 3.55.  The
-    refraction types is 0-3 specify 0) Air - 1.00, 1) Water - 1.33,
-) Glass - 1.67 or 3) Crystal 2.00.
-SPEC - size 2 - not written by Imagine - see SPC1 above.
-    UBYTE   Specularity;    ; range of 0-255
-    UBYTE   Hardness;       ; specular exponent (0-31)
-    This chunk contains specular information.  The Specularity
-    field is the amount of specular reflection -- 0 is none,
-is fully specular.  The &quot;specular exponent&quot; controls
-    the &quot;tightness&quot; of the specular spots.  A value of zero
-    gives broad specular spots and a value of 31 gives smaller
-    spots.
-PRP0 - size 6 - not written by Imagine
-    UBYTE   Props[6];       ; more object properties
-    This chunk contains object properties that programs other
-    than Turbo Silver might support.
-    Props[0] - PRP_BLEND    ; blending factor (0-255)
-    Props[1] - PRP_SMOOTH   ; roughness factor
-    Props[2] - PRP_SHADE    ; shading on/off flag
-    Props[3] - PRP_PHONG    ; phong shading on/off flag
-    Props[4] - PRP_GLOSSY   ; glossy on/off flag
-    Props[5] - PRP_QUICK    ; Quickdraw on/off flag
-    The blending factor controls the amount of dithering used
-    on the object - 255 is fully dithered.
-    The roughness factor controls how rough the object should
-    appear - 0 is smooth, 255 is max roughness.
-    The shading flag is interpreted differently depending on
-    whether the object is a light source or not.  For light
-    sources, it sets the light to cast shadows or not.  For
-    normal objects, if the flag is set, the object is always
-    considered as fully lit - i.e. it's color is read directly
-    from the object (or IFF brush), and is not affected by light
-    sources.
-    The phong shading is on by default - a non-zero value turns
-    it off.
-    The glossy flag sets the object to be glossy or not.  If
-    the object is glossy, the &quot;transmit&quot; colors and the index
-    of refraction control the amount of &quot;sheen&quot;.  The glossy
-    feature is meant to simulate something like a wax coating
-    on the object with the specified index of refraction. The
-    trasmission coefficients control how much light from the
-    object makes it through the wax coating.
-    The Quickdraw flag, if set, tells the editor not to draw
-    all the points and edges for the object, but to draw a
-    rectanglular solid centered at the object position, and
-    with sizes detemined by the axis lengths.
-PRP1 - size 8 - Imagine only
-    UBYTE   IProps[8];       ; more object properties
-    This chunk contains object properties that programs other
-    than Imagine might support.
-    IProps[0] - IPRP_DITHER   ; blending factor (0-255)
-    IProps[1] - IPRP_HARD     ; hardness factor (0-255)
-    IProps[2] - IPRP_ROUGH    ; roughness factor (0-255)
-    IProps[3] - IPRP_SHINY    ; shinyness factor (0-255)
-    IProps[4] - IPRP_INDEX    ; index of refraction
-    IProps[5] - IPRP_QUICK    ; flag - Quickdraw on/off
-    IProps[6] - IPRP_PHONG    ; flag - Phong shading on/off
-    IProps[7] - IPRP_GENLOCK  ; flag - Genlock on/off
-    The blending factor controls the amount of dithering used
-    on the object - 255 is fully dithered.
-    The hardness factor controls how tight the specular spot
-    should be - 0 is a big soft spot, 255 is a tight hot spot
-    The roughness factor controls how rough the object should
-    appear - 0 is smooth, 255 is max roughness.
-    The shiny factor in interaction with the object's filter
-    values controls how shiny the object appears.  Setting it
-    to anything but zero forces the object to be non-transparent
-    since then the filter values are used in the shiny (reflection)
-    calculations.  A value of 255 means maximum shinyness.
-INTS - size 4 - not written by Imagine
-    FRACT   Intensity;      ; light intensity
-    This is the intensity field for light source objects.
-    an intensity of 255 for a sun-like light fully lights
-    object surfaces which are perpendicular to the direction
-    to the light source.  For lamp-like light sources, the
-    necessary intensity will depend on the distance to the light.
-INT1 - size 12 - Imagine only
-    VECTOR  Intensity;      ; light intensity
-    This is like INTS above, but has seperate R, G &amp; B intensities.
-STRY - size 56 - not written by Imagine
-    STORY   story;          ; a story structure for the object.
-    The story structure is described above.
-ANID - size 64 - Imagine only
-    LONG    Cellno;         ; cell number
-    TFORM   TForm;          ; object position/axes/size in that cell.
-    For Imagine's &quot;Cycle&quot; objects, within EACH DESC chunk in the
-    file - that is, for each object of the group, there will be
-    a series of ANID chunks.  The cell number sequences of each
-    part of the must agree with the sequence for the head object,
-    and the first cell number must be zero.
-FORD - size 56 + 12 * PC - Imagine only
-    WORD    NumC;           ; number of cross section points
-    WORD    NumF;           ; number of slices
-    WORD    Flags;          ; orientation flag
-    WORD    pad;            ; reserved
-    MATRIX  TForm;          ; object rotation/scaling transformation
-    VECTOR  Shift;          ; object translation
-    VECTOR  Points[PC];     ; &quot;Forms&quot; editor points
-    For Imagine's &quot;Forms&quot; objects, the &quot;PNTS&quot; chunk above is not
-    written out, but this structure is written instead.  The point
-    count is PC = NumC + 4 * NumF.  The object's real points are
-    then calculated from these using a proprietary algorithm.
-    The tranformation parameters above allow the axes of the
-    real object be moved around relative to the &quot;Forms&quot; points.
-DESC notes
-----------
-Again, most of these fields are optional, and defaults are supplied.
-However, if there is a FACE chunk, there must also be a CLST chunk,
-an RLST chunk and a TLST chunk -- all with matching &quot;count&quot; fields.
-The SHAP chunk is not optional.
-Defaults are:  Colors set to (240,240,240); reflection and
-transmission coefficients set to zero; illegal shape; no story or
-special surface types; position at (0,0,0); axes aligned to the
-world axes; size fields all 32.0; intensity at 300; no name;
-no points/edges or faces; texture parameters set to zero; refraction
-type 0 with index 1.00; specular, hardness and roughness set to zero;
-blending at 255; glossy off; phong shading on; not a light source;
-not brightly lit;
-In Imagine, defaults are the same, but with colors (255,255,255).
-INFO sub-chunks
----------------
-BRSH - size 82
-    WORD    Number;        ; Brush number (between 0 and 7)
-    CHAR    Filename[80];  ; IFF ILBM filename
-    There may be more than one of these.
-STNC - size 82
-    Same format as BRSH chunk.
-TXTR - size 82
-    Same format as BRSH chunk.  The Filename field is the name of
-    a code module that can be loaded with LoadSeg().
-OBSV - size 28
-    VECTOR  Camera;         ; Camera position
-    VECTOR  Rotate;         ; Camera rotation angles
-    FRACT   Focal;          ; Camera focal length
-    This tells where the camera is, how it is aimed, and its
-    focal length.  The rotation angles are in degrees, and specify
-    rotations around the X, Y, and Z axes.  The camera looks down
-    its own Y axis, with the top of the picture in the direction of
-    the Z axis.  If the rotation angles are all zero, its axes
-    are aligned with the world coordinate axes.  The rotations are
-    performed in the order ZXY about the camera axes.  A positive
-    angle rotates Y toward Z, Z toward X, and X toward Y for
-    rotations about the X, Y, and Z axes respectively.  To
-    understand the focal length, imagine a 320 x 200 pixel
-    rectangle perpendicular to, and centered on the camera's
-    Y axis.  Any objects in the infinite rectangular cone defined
-    by the camera position and the 4 corners of the rectangle will
-    appear in the picture.
-OTRK - size 18
-    BYTE    Trackname[18];
-    This chunk specifies the name of an object that the camera
-    is &quot;tracked&quot; to.  If the name is NULL, the camera doesn't
-    track.  Otherwise, if the object is moved inside Turbo Silver,
-    the camera will follow it.
-OSTR - size 56
-    STORY   CStory;         ; a STORY structure for the camera
-    The story structure is defined above.
-FADE - size 12
-    FRACT   FadeAt;         ; distance to start fade
-    FRACT   FadeBy;         ; distance of total fade
-    BYTE    pad;            ; pad byte - must be zero
-    COLOR   FadeTo;         ; RGB color to fade to
-SKYC - size 8
-    BYTE    pad;            ; pad byte - must be zero
-    COLOR   Horizon;        ; horizon color
-    BYTE    pad;            ; pad byte - must be zero
-    COLOR   Zenith;         ; zenith color
-AMBI - size 4
-    BYTE    pad;            ; pad byte - must be zero
-    COLOR   Ambient;        ; abmient light color
-GLB0 - size 8
-    BYTE    Props[8];       ; an array of 8 &quot;global properties&quot; used
-                            ; by Turbo Silver.
-    Props[0] - GLB_EDGING       ; edge level (globals requester)
-    Props[1] - GLB_PERTURB      ; perturbance (globals requester)
-    Props[2] - GLB_SKY_BLEND    ; sky blending factor (0-255)
-    Props[3] - GLB_LENS         ; lens type (see below)
-    Props[4] - GLB_FADE         ; flag - Sharp/Fuzzy focus (globals)
-    Props[5] - GLB_SIZE         ; &quot;apparant size&quot; (see below)
-    Props[6] - GLB_RESOLVE      ; resolve depth (globals requester)
-    Props[7] - GLB_EXTRA        ; flag - genlock sky on/off
-    The edging and perturbance values control the heuristics in
-    ray tracing.  The sky blending factor is zero for no blending,
-    and 255 for full blending.  The lens type is a number from 0
-, corresponding to the boxes in the &quot;camera&quot; requester, and
-    correspond to 0) Manual, 1) Wide angle, 2) Normal, 3) Telephoto,
-    and 4) Custom.  It is used in setting the camera's focal length
-    if the camera is tracked to an object.  The Sharp/Fuzzy flag
-    turns the &quot;fade&quot; feature on and off - non-zero means on.
-    The &quot;apparant size&quot; parameter is 100 times the &quot;custom size&quot;
-    parameter in the camera requester.  And is used to set the
-    focal length for a custom lens.  The &quot;resolve depth&quot; controls
-    the number of rays the ray tracer will shoot for a single pixel.
-    Each reflective/refractive ray increments the depth counter, and
-    the count is never allowed to reach the &quot;resolve depth&quot;.  If both
-    a reflective and a refractive ray are traced, each ray gets its
-    own version of the count - so theoretically, a resolve depth of
-could allow much more than 4 rays to be traced.  The &quot;genlock
-    sky&quot; flag controls whether the sky will be colored, or set to
-    the genlock color (color 0 - black) in the final picture.
-All of the INFO sub-chunks are optional, as is the INFO chunk.
-Default values are supplied if the chunks are not present.  The
-defaults are:  no brushes, stencils, or textures defined; no story
-for the camera; horizon and zenith and ambient light colors set
-to black; fade color set to (80,80,80);  un-rotated, un-tracked
-camera at (-100, -100, 100); and global properties array set to
-[30, 0, 0, 0, 0, 100, 8, 0].
-EXTR sub-sub-chunks
--------------------
-MTRX - size 60
-    VECTOR  Translate;      ; translation vector
-    VECTOR  Scale;          ; X,Y and Z scaling factors
-    MATRIX  Rotate;         ; rotation matrix
-    The translation vector is i world coordinates.
-    The scaling factors are with respect to local axes.
-    The rotation matrix is with respect to the world axes,
-    and it should be a &quot;unit matrix&quot;.
-    The rotation is such that a rotated axis's X,Y, and Z
-    components are the dot products of the MATRIX's I,J,
-    and K vectors with the un-rotated axis vector.
-LOAD - size 80
-    BYTE    Filename[80];   ; the name of the external file
-    This chunk contains the name of an external object file.
-    The external file should be a FORM TDDD file.  It may contain
-    an any number of objects possibly grouped into heirarchy(ies).
-Both of these chunks are required.</pre>
-=== ProWrite document format ===
-<pre>IFF FORM / CHUNK DESCRIPTION
-============================
-Form/Chunk IDs:
-   FORM   WORD
-   Chunks FONT,COLR,DOC,HEAD,FOOT,PCTS,PARA,TABS,PAGE,TEXT,FSCC,PINF
-Date Submitted: 03/87
-Submitted by:   James Bayless - New Horizons Software, Inc.
-FORM
-====
-FORM ID:  WORD
-FORM Purpose:  Document storage (supports color, fonts, pictures)
-FORM Description:
-This include file describes FORM WORD and its Chunks
-/*
- *      IFF Form WORD structures and defines
- *      Copyright (c) 1987 New Horizons Software, Inc.
- *
- *      Permission is hereby granted to use this file in any and all
- *      applications.  Modifying the structures or defines included
- *      in this file is not permitted without written consent of
- *      New Horizons Software, Inc.
- */
-#include &quot;:IFF/ILBM.h&quot;        /* Makes use of ILBM defines */
-#define ID_WORD      MakeID('W','O','R','D')      /* Form type */
-#define ID_FONT      MakeID('F','O','N','T')      /* Chunks */
-#define ID_COLR      MakeID('C','O','L','R')
-#define ID_DOC       MakeID('D','O','C',' ')
-#define ID_HEAD      MakeID('H','E','A','D')
-#define ID_FOOT      MakeID('F','O','O','T')
-#define ID_PCTS      MakeID('P','C','T','S')
-#define ID_PARA      MakeID('P','A','R','A')
-#define ID_TABS      MakeID('T','A','B','S')
-#define ID_PAGE      MakeID('P','A','G','E')
-#define ID_TEXT      MakeID('T','E','X','T')
-#define ID_FSCC      MakeID('F','S','C','C')
-#define ID_PINF      MakeID('P','I','N','F')
-/*
- *   Special text characters for page number, date, and time
- *   Note:  ProWrite currently supports only PAGENUM_CHAR, and only in
- *      headers and footers
- */
-#define PAGENUM_CHAR   0x80
-#define DATE_CHAR      0x81
-#define TIME_CHAR      0x82
-/*
- *   Chunk structures follow
- */
-/*
- *   FONT - Font name/number table
- *   There are one of these for each font/size combination
- *   These chunks should appear at the top of the file (before document data)
- */
-typedef struct {
-   UBYTE   Num;         /* 0 .. 255 */
-   UWORD   Size;
-/* UBYTE   Name[];      */   /* NULL terminated, without &quot;.font&quot; */
-} FontID;
-/*
- *   COLR - Color translation table
- *   Translates from color numbers used in file to ISO color numbers
- *   Should be at top of file (before document data)
- *   Note:  Currently ProWrite only checks these values to be its current map,
- *      it does no translation as it does for FONT chunks
- */
-typedef struct {
-   UBYTE   ISOColors[8];
-} ISOColors;
-/*
- *   DOC - Begin document section
- *   All text and paragraph formatting following this chunk and up to a
- *   HEAD, FOOT, or PICT chunk belong to the document section
- */
-#define PAGESTYLE_1   0      /* 1, 2, 3 */
-#define PAGESTYLE_I   1      /* I, II, III */
-#define PAGESTYLE_i   2      /* i, ii, iii */
-#define PAGESTYLE_A   3      /* A, B, C */
-#define PAGESTYLE_a   4      /* a, b, c */
-typedef struct {
-   UWORD   StartPage;      /* Starting page number */
-   UBYTE   PageNumStyle;   /* From defines above */
-   UBYTE   pad1;
-   LONG    pad2;
-} DocHdr;
-/*
- *   HEAD/FOOT - Begin header/footer section
- *   All text and paragraph formatting following this chunk and up to a
- *   DOC, HEAD, FOOT, or PICT chunk belong to this header/footer
- *   Note:  This format supports multiple headers and footers, but currently
- *      ProWrite only allows a single header and footer per document
- */
-#define PAGES_NONE   0
-#define PAGES_LEFT   1
-#define PAGES_RIGHT  2
-#define PAGES_BOTH   3
-typedef struct {
-   UBYTE   PageType;       /* From defines above */
-   UBYTE   FirstPage;      /* 0 = Not on first page */
-   LONG   pad;
-} HeadHdr;
-/*
- *   PCTS - Begin picture section
- *   Note:  ProWrite currently requires NPlanes to be three (3)
- */
-typedef struct {
-   UBYTE   NPlanes;      /* Number of planes used in picture bitmaps */
-   UBYTE   pad;
-} PictHdr;
-/*
- *   PARA - New paragraph format
- *   This chunk should be inserted first when a new section is started (DOC,
- *      HEAD, or FOOT), and again whenever the paragraph format changes
- */
-#define SPACE_SINGLE   0
-#define SPACE_DOUBLE   0x10
-#define JUSTIFY_LEFT    0
-#define JUSTIFY_CENTER  1
-#define JUSTIFY_RIGHT   2
-#define JUSTIFY_FULL    3
-#define MISCSTYLE_NONE   0
-#define MISCSTYLE_SUPER  1      /* Superscript */
-#define MISCSTYLE_SUB    2      /* Subscript */
-typedef struct {
-   UWORD   LeftIndent;    /* In decipoints (720 dpi) */
-   UWORD   LeftMargin;
-   UWORD   RightMargin;
-   UBYTE   Spacing;       /* From defines above */
-   UBYTE   Justify;       /* From defines above */
-   UBYTE   FontNum;       /* FontNum, Style, etc. for first char in para*/
-   UBYTE   Style;         /* Standard Amiga style bits */
-   UBYTE   MiscStyle;     /* From defines above */
-   UBYTE   Color;         /* Internal number, use COLR to translate */
-   LONG    pad;
-} ParaFormat;
-/*
- *   TABS - New tab stop types/locations
- *   Use an array of values in each chunk
- *   Like the PARA chunk, this should be inserted whenever the tab settings
- *      for a paragraph change
- *   Note:  ProWrite currently does not support TAB_CENTER
- */
-#define TAB_LEFT     0
-#define TAB_CENTER   1
-#define TAB_RIGHT    2
-#define TAB_DECIMAL  3
-typedef struct {
-   UWORD   Position;      /* In decipoints */
-   UBYTE   Type;
-   UBYTE   pad;
-} TabStop;
-/*
- *   PAGE - Page break
- *   Just a marker -- this chunk has no data
- */
-/*
- *   TEXT - Paragraph text (one block per paragraph)
- *   Block is actual text, no need for separate structure
- *   If the paragraph is empty, this is an empty chunk -- there MUST be
- *   a TEXT block for every paragraph
- *   Note:  The only ctrl characters ProWrite can currently handle in TEXT
- *   chunks are Tab and PAGENUM_CHAR, ie no Return's, etc.
- */
-/*
- *   FSCC - Font/Style/Color changes in previous TEXT block
- *   Use an array of values in each chunk
- *   Only include this chunk if the previous TEXT block did not have
- *      the same Font/Style/Color for all its characters
- */
-typedef struct {
-   UWORD   Location;      /* Character location in TEXT chunk of change */
-   UBYTE   FontNum;
-   UBYTE   Style;
-   UBYTE   MiscStyle;
-   UBYTE   Color;
-   UWORD   pad;
-} FSCChange;
-/*
- *   PINF - Picture info
- *   This chunk must only be in a PCTS section
- *   Must be followed by ILBM BODY chunk
- *   Pictures are treated independently of the document text (like a
- *      page-layout system), this chunk includes information about what
- *      page and location on the page the picture is at
- *   Note:  ProWrite currently only supports mskTransparentColor and
- *      mskHasMask masking
- */
-typedef struct {
-   UWORD         Width, Height;   /* In pixels */
-   UWORD         Page;         /* Which page picture is on (0..max) */
-   UWORD         XPos, YPos;      /* Location on page in decipoints */
-   Masking       Masking;      /* Like ILBM format */
-   Compression   Compression;   /* Like ILBM format */
-   UBYTE         TransparentColor;   /* Like ILBM format */
-   UBYTE         pad;
-} PictInfo;
-/* end */</pre>
-== Additional documents ==
-=== Intro to IFF Amiga ILBM Files and Amiga Viewmodes ===
-The IFF (Interchange File Format) for graphic images on the Amiga is called FORM ILBM (InterLeaved BitMap). It follows a standard parsable IFF format.
-==== Sample hex dump of beginning of an ILBM ====
-Important note! You can NOT ever depend on any particular ILBM chunk being at any particular offset into the file! IFF files are composed, in their simplest form, of chunks within a FORM. Each chunk starts starts with a 4-letter chunkID, followed by a 32-bit length of the rest of the chunk. You PARSE IFF files, skipping past unneeded or unknown chunks by seeking their length (+1 if odd length) to the next 4-letter chunkID.
-<pre>0000: 464F524D 00016418 494C424D 424D4844    FORM..d.ILBMBMHD
-: 00000014 01400190 00000000 06000100    .....@..........
-: 00000A0B 01400190 43414D47 00000004    .....@..CAMG....
-: 00000804 434D4150 00000030 001100EE    ....CMAP...0....
-: EEEE0000 22000055 33333355 55550033    .... ..P000PPP.0
-: 99885544 77777711 66EE2266 EE6688DD    ..P@ppp.`. `.`..
-: AAAAAAAA 99EECCCC CCDDAAEE 424F4459    ............BODY
-: 000163AC F8000F80 148A5544 2ABDEFFF    ..c.......UD*...  etc.</pre>
-Interpretation:
-<pre>      'F O R M' length  'I L B M''B M H D'&lt;-start of BitMapHeader chunk
-: 464F524D 00016418 494C424D 424D4844    FORM..d.ILBMBMHD
-       length  WideHigh XorgYorg PlMkCoPd &lt;- Planes Mask Compression Pad
-: 00000014 01400190 00000000 06000100    .....@..........
-                                             start of C-AMiGa
-      TranAspt PagwPagh 'C A M G' length  &lt;- View modes chunk
-: 00000A0B 01400190 43414D47 00000004    .....@..CAMG....
-      Viewmode 'C M A P' length  R g b R  &lt;- Viewmode 800=HAM | 4=LACE
-: 00000804 434D4150 00000030 001100EE    ....CMAP...0....
-      g b R g  b R g b  R g b R  g b R g  &lt;- Rgb's are for reg0 thru regN
-: EEEE0000 22000055 33333355 55550033    .... ..P000PPP.0
-      b R g b  R g b R  g b R g  b R g b
-: 99885544 77777711 66EE2266 EE6688DD    ..P@ppp.`. `.`..
-      R g b R  g b R g  b R g b 'B O D Y'
-: AAAAAAAA 99EECCCC CCDDAAEE 424F4459    ............BODY
-                                             Compacted
-       length   start of body data        &lt;- (Compression=1 above)
-: 000163AC F8000F80 148A5544 2ABDEFFF    ..c.......UD*...
-: FFBFF800 0F7FF7FC FF04F85A 77AD5DFE    ...........Zw.].  etc.
-Notes on CAMG Viewmodes:  HIRES=0x8000  LACE=0x4  HAM=0x800  HALFBRITE=0x80</pre>
-=== Interpreting ILBMs ===
-ILBM is a fairly simple IFF FORM. All you really need to deal with to extract the image are the following chunks:
-<pre>(Note - Also watch for AUTH Author chunks and (c) Copyright chunks
- and preserve any copyright information if you rewrite the ILBM)
-   BMHD - info about the size, depth, compaction method
-          (See interpreted hex dump above)
-   CAMG - optional Amiga viewmodes chunk
-          Most HAM and HALFBRITE ILBMs should have this chunk.  If no
-          CAMG chunk is present, and image is 6 planes deep, assume
-          HAM and you'll probably be right.  Some Amiga viewmodes
-          flags are HIRES=0x8000, LACE=0x4, HAM=0x800, HALFBRITE=0x80.
-        Note that new Amiga 2.0 ILBMs may have more complex 32-bit
-        numbers (modeid) stored in the CAMG.  However, the bits
-        described above should get you a compatible old viewmode.
-   CMAP - RGB values for color registers 0 to n
-          (each component left justified in a byte)
-        If a deep ILBM (like 12 or 24 planes), there should be no CMAP
-        and instead the BODY planes are interpreted as the bits of RGB
-        in the order R0...Rn G0...Gn B0...Bn
-   BODY - The pixel data, stored in an interleaved fashion as follows:
-          (each line individually compacted if BMHD Compression = 1)
-             plane 0 scan line 0
-             plane 1 scan line 0
-             plane 2 scan line 0
-             ...
-             plane n scan line 0
-             plane 0 scan line 1
-             plane 1 scan line 1
-             etc.</pre>
-=== Body Compression ===
-The BODY contains pixel data for the image. Width, Height, and depth (Planes) is specified in the BMHD.
-If the BMHD Compression byte is 0, then the scan line data is not compressed. If Compression=1, then each scan line is individually compressed as follows:
-More than 2 bytes the same stored as BYTE code value n from -1 to -127 followed by byte to be repeated (-n) + 1 times. Varied bytes stored as BYTE code n from 0 to 127 followed by n+1 bytes of data.
-The byte code -128 is a NOP.
-=== Interpreting the Scan Line Data ===
-If the ILBM is not HAM or HALFBRITE, then after parsing and uncompacting if necessary, you will have N planes of pixel data. Color register used for each pixel is specified by looking at each pixel thru the planes. I.e., if you have 5 planes, and the bit for a particular pixel is set in planes 0 and 3:
-<pre>PLANE     4 3 2 1 0
-PIXEL     0 1 0 0 1</pre>
-then that pixel uses color register binary 01001 = 9
-The RGB value for each color register is stored in the CMAP chunk of the ILBM, starting with register 0, with each register’s RGB value stored as one byte of R, one byte G, and one byte of B, with each component scaled to 8-bits. (ie. 4-bit Amiga R, G, and B components are each stored in the high nibble of a byte. The low nibble may also contain valid data if the color was stored with 8-bit-per-gun color resolution).
-BUT - if the picture is '''HAM''' or '''HALFBRITE''', it is interpreted differently.
-Hopefully, if the picture is HAM or HALFBRITE, the package that saved it properly saved a CAMG chunk (look at a hex dump of your file with ACSII interpretation - you will see the chunks - they all start with a 4-ASCII- character chunk ID). If the picture is 6 planes deep and has no CAMG chunk, it is probably HAM. If you see a CAMG chunk, the &quot;CAMG&quot; is followed by the 32-bit chunk length, and then the 32-bit Amiga Viewmode flags.
-HAM pics with a 16-bit CAMG will have the 0x800 bit set in CAMG ViewModes. HALBRITE pics will have the 0x80 bit set.
-To transport a HAM or HALFBRITE picture to another machine, you must understand how HAM and HALFBRITE work on the Amiga.
-==== How Amiga HAM mode works ====
-Amiga HAM (Hold and Modify) mode lets the Amiga display all 4096 RGB values. In HAM mode, the bits in the two last planes describe an R G or B modification to the color of the previous pixel on the line to create the color of the current pixel. So a 6-plane HAM picture has 4 planes for specifying absolute color pixels giving up to 16 absolute colors which would be specified in the ILBM CMAP chunk. The bits in the last two planes are color modification bits which cause the Amiga, in HAM mode, to take the RGB value of the previous pixel (Hold and), substitute the 4 bits in planes 0-3 for the previous color’s R G or B component (Modify) and display the result for the current pixel. If the first pixel of a scan line is a modification pixel, it modifies the RGB value of the border color (register 0). The color modification bits in the last two planes (planes 4 and 5) are interpreted as follows:
-<pre>   00 - no modification.  Use planes 0-3 as normal color register index
-- hold previous, replacing Blue component with bits from planes 0-3
-- hold previous, replacing Red component with bits from planes 0-3
-- hold previous. replacing Green component with bits from planes 0-3</pre>
-==== How Amiga HALFBRITE mode works ====
-This one is simpler. In HALFBRITE mode, the Amiga interprets the bit in the last plane as HALFBRITE modification. The bits in the other planes are treated as normal color register numbers (RGB values for each color register is specified in the CMAP chunk). If the bit in the last plane is set (1), then that pixel is displayed at half brightness. This can provide up to 64 absolute colors.
-=== Other Notes ===
-Amiga ILBMs images must be a even number of bytes wide. Smaller images (such as brushes) are padded to an even byte width.
-ILBMs created with Electronic Arts IBM and Amiga “DPaintII” packages are compatible (though you may have to use a ’.lbm’ filename extension on an IBM). The ILBM graphic files may be transferred between the machines (or between the Amiga and IBM sides your Amiga if you have a CBM Bridgeboard card installed) and loaded into either package.