View source for FAXX IFF Facsimile Image

= FAXX =

<pre>
FAXX (Facsimile image FORM)

IFF FORM / CHUNK DESCRIPTION
============================

Form/Chunk IDs:
    FORM:   FAXX
    Chunks: FXHD, PAGE, FLOG

Date Submitted: 11/13/91
Submitted by:   Christopher E. Darsch - Atlantis Design Group, Inc.
Revision:       1.0


FXHD Chunk
==========

    The required property chunk "FXHD" contains a FaxHeader as defined in
the following header file.  The FaxHeader contains data necessary to interpret
the data chunk "PAGE".  The pixel size of the image can be determined from the
contents of the FaxHeader structure, as well as the dimensions of the source
document.  The compression method used to encode the "PAGE" chunk is also part
of the FaxHeader.

PAGE Chunk
==========

    The required data chunk "PAGE" contains the encoded bit-packed fax image
data that is transmitted/received during phase C of a facsimile communication.
The data always begins with a fax EOL (End of line = 0x001) and ends
with a fax RTC (Return to control = six consecutive EOLs).

    A multiple-page fax can be stored variously as multiple files or, most
preferably, as an IFF LIST object with a shared FXHD chunk.

FLOG Chunk
==========

    The optional data chunk "FLOG" contains log information about a received
fax.  The specification for this chunk will be submitted at a later date.



/***************************************************************************/
/* FaxxIFF.h                                                               */
/***************************************************************************/

#define ID_FAXX     MakeID('F','A','X','X')
#define ID_FXHD     MakeID('F','X','H','D')
#define ID_PAGE     MakeID('P','A','G','E')
#define ID_FLOG     MakeID('F','L','O','G')

/* LineLength Codes */

#define FXLNGSTD    215     /* 1728 pixels along std line lng of 215mm */
#define FXLNGLONG   255     /* 2048 pixels along opt line lng of 255mm */
#define FXLNGLONGER 303     /* 2432 pixels along opt line lng of 303mm */
#define FXLNGA5     151     /* 1216/1728 pixels along opt line lng of 151mm */
#define FXLNGA6     107     /* 864/1728 pixels along opt line lng of 107mm */

/* VRes Codes */

#define FXVRESNORM  385     /* Normal resolution: 3.85 lines/mm */
#define FXVRESFINE  770     /* Fine resolution: 7.7 lines/mm */

/* Compression Codes */
/* Codes 129, 130, and 131 are reserved */

#define FXCMPNONE   0       /* No compression -- available under Group IV */
#define FXCMPMH     1       /* One-dimensional (MH) coding */
#define FXCMPMR     2       /* Two-dimensional (MR) coding */
#define FXCMPMMR    4       /* Modified Two-dimensional (MMR) coding */

typedef struct {
    UWORD Width, Height;    /* Image width and height, in pixels */
    UWORD LineLength;       /* Scan line length, in millimeters */
    UWORD VRes;             /* Vertical Resolution, in lines/100mm */
    UBYTE Compression;      /* Compression method */
    UBYTE Pad[11];          /* Room for expansion */
} FaxHeader;

==========================


Note:  You may also find "GPHD" chunks in FAXX files.   This is an
additional header used by one software producer.  See "FAXX.GPHD.doc"
</pre>


== FAXX.GPHD ==

<pre>
Additional header info for FAXX FORMs

/************************************************************************
*  			FAX_IFF.H					*
*									*
* 		Defined by R Carde - GPSoftware				*
*			21 Aloomba Rd Ashgrove Auastralia 4060		*
*			UseNet cbmvax!cbmaus!vogue!richard		*
*									*
* 		Issue  1	12.12.91				*
*		Issue  2	01.02.92				*
*									*
************************************************************************/


/************************************************************************
*	define as FAX form for any Group 3 fax 				*
************************************************************************/

#define ID_GPHD     MakeID('G','P','H','D')	/* our CHUNK */

#define	VRES_STD	0		/* standard mode 98 DPI 	*/
#define	VRES_FINE	1		/* fine res 198 DPI 		*/

#define	COMP_NONE	255		/* no compression- binary file 	*/
#define	COMP_1D		0		/* 1-D modified HUFFMAN 	*/
#define	COMP_2D		1		/* 2-D modified REED 		*/
#define	COMP_2DU	2		/* 2-D uncompressed REED 	*/
#define	COMP_2DM	3		/* 2-D modified modified REED 	*/

					/* VR-std scan time VR-fine	*/
#define	ST_0_0MS	0		/* 0ms 		  0ms 		*/
#define	ST_5_5MS	1		/* 5ms 		  5ms		*/
#define	ST_10_5MS	2		/* 10ms 	  5ms		*/
#define	ST_10_10MS	3		/* 10ms 	  10ms		*/
#define	ST_20_10MS	4		/* 20ms 	  10ms		*/
#define	ST_20_20MS	5		/* 20ms 	  20ms		*/
#define	ST_40_20MS	6		/* 40ms 	  20ms		*/
#define	ST_40_40MS	7		/* 40ms 	  40ms		*/

#define	PW_1728		0		/* 1728 pels in 215 mm 		*/
#define	PW_2048		1		/* 2048 pels in 255 mm 		*/
#define	PW_2432		2		/* 2432 pels in 303 mm 		*/
#define	PW_1216		3		/* 1216 pels in 151 mm 		*/
#define	PW_864		4		/* 864 pels in 107 mm 		*/

#define	PH_UNLIM	0		/* unlimited page length 	*/
#define	PH_A4		1		/* A4 PAGE 297 mm 		*/
#define	PH_B4		2		/* B4 PAGE 364 mm 		*/

#define	BR_2400		0		/* 2400 bits per second		*/
#define	BR_4800		1
#define	BR_7200		2
#define	BR_9600		3
#define	BR_12000	4
#define	BR_14400	5

#define	ECM_NONE	0		/* Error Correction Disabled	*/
#define	ECM_STD		1		/* Error Correction Enabled	*/ 

#define	BFT_NONE	0		/* Binary Transfer Disabled	*/
#define	BFT_STD		1		/* Binary Transfer Enabled	*/ 

struct  GPHD {
	UWORD	gp_Width;		/* width in pels 		*/
	UWORD	gp_Length;		/* length / height in pels	*/
	UWORD	gp_Page;		/* page number 			*/
	UBYTE	gp_ID[22];		/* id string 20 ch NULL term	*/

	UBYTE	gp_VRes;		/* Vertical Res dpi		*/
	UBYTE	gp_BitRate;		/* connection bit rate		*/
	UBYTE	gp_PageWidth;		/* page width 			*/
	UBYTE	gp_PageLength;		/* page length/height 		*/
	UBYTE	gp_Compression;		/* compression method 		*/
	UBYTE	gp_ErrorCorrection;	/* ECM mode			*/
	UBYTE	gp_BinaryFileTransfer;	/* binary transfer mode		*/
	UBYTE	gp_ScanTime;		/* Scan Time ms			*/

	struct	DateStamp gp_Date;	/* date sent/received 		*/
	UBYTE	gp_Pad[10];
};
</pre>