tif_fax3.c

一个国人自己实现图像库的程序（有参考价值）

		}
		bp += sp->b.rowbytes;
		cc -= sp->b.rowbytes;
		if (cc != 0)
			tif->tif_row++;
	}
	return (1);
}

static int
Fax3PostEncode(TIFF* tif)
{
	Fax3EncodeState* sp = EncoderState(tif);

	if (sp->bit != 8)
		Fax3FlushBits(tif, sp);
	return (1);
}

static void
Fax3Close(TIFF* tif)
{
	if ((Fax3State(tif)->mode & FAXMODE_NORTC) == 0) {
		Fax3EncodeState* sp = EncoderState(tif);
		u_int code = EOL;
		u_int length = 12;
		int i;

		if (is2DEncoding(sp))
			code = (code<<1) | (sp->tag == G3_1D), length++;
		for (i = 0; i < 6; i++)
			Fax3PutBits(tif, code, length);
		Fax3FlushBits(tif, sp);
	}
}

static void
Fax3Cleanup(TIFF* tif)
{
	if (tif->tif_data) {
		if (Fax3State(tif)->rw_mode == O_RDONLY) {
			Fax3DecodeState* sp = DecoderState(tif);
			if (sp->runs)
				_TIFFfree(sp->runs);
		} else {
			Fax3EncodeState* sp = EncoderState(tif);
			if (sp->refline)
				_TIFFfree(sp->refline);
		}
		if (Fax3State(tif)->subaddress)
			_TIFFfree(Fax3State(tif)->subaddress);
		_TIFFfree(tif->tif_data);
		tif->tif_data = NULL;
	}
}

#define	FIELD_BADFAXLINES	(FIELD_CODEC+0)
#define	FIELD_CLEANFAXDATA	(FIELD_CODEC+1)
#define	FIELD_BADFAXRUN		(FIELD_CODEC+2)
#define	FIELD_RECVPARAMS	(FIELD_CODEC+3)
#define	FIELD_SUBADDRESS	(FIELD_CODEC+4)
#define	FIELD_RECVTIME		(FIELD_CODEC+5)

#define	FIELD_OPTIONS		(FIELD_CODEC+6)

static const TIFFFieldInfo faxFieldInfo[] = {
    { TIFFTAG_FAXMODE,		 0, 0,	TIFF_ANY,	FIELD_PSEUDO,
      FALSE,	FALSE,	"FaxMode" },
    { TIFFTAG_FAXFILLFUNC,	 0, 0,	TIFF_ANY,	FIELD_PSEUDO,
      FALSE,	FALSE,	"FaxFillFunc" },
    { TIFFTAG_BADFAXLINES,	 1, 1,	TIFF_LONG,	FIELD_BADFAXLINES,
      TRUE,	FALSE,	"BadFaxLines" },
    { TIFFTAG_BADFAXLINES,	 1, 1,	TIFF_SHORT,	FIELD_BADFAXLINES,
      TRUE,	FALSE,	"BadFaxLines" },
    { TIFFTAG_CLEANFAXDATA,	 1, 1,	TIFF_SHORT,	FIELD_CLEANFAXDATA,
      TRUE,	FALSE,	"CleanFaxData" },
    { TIFFTAG_CONSECUTIVEBADFAXLINES,1,1, TIFF_LONG,	FIELD_BADFAXRUN,
      TRUE,	FALSE,	"ConsecutiveBadFaxLines" },
    { TIFFTAG_CONSECUTIVEBADFAXLINES,1,1, TIFF_SHORT,	FIELD_BADFAXRUN,
      TRUE,	FALSE,	"ConsecutiveBadFaxLines" },
    { TIFFTAG_FAXRECVPARAMS,	 1, 1, TIFF_LONG,	FIELD_RECVPARAMS,
      TRUE,	FALSE,	"FaxRecvParams" },
    { TIFFTAG_FAXSUBADDRESS,	-1,-1, TIFF_ASCII,	FIELD_SUBADDRESS,
      TRUE,	FALSE,	"FaxSubAddress" },
    { TIFFTAG_FAXRECVTIME,	 1, 1, TIFF_LONG,	FIELD_RECVTIME,
      TRUE,	FALSE,	"FaxRecvTime" },
};
static const TIFFFieldInfo fax3FieldInfo[] = {
    { TIFFTAG_GROUP3OPTIONS,	 1, 1,	TIFF_LONG,	FIELD_OPTIONS,
      FALSE,	FALSE,	"Group3Options" },
};
static const TIFFFieldInfo fax4FieldInfo[] = {
    { TIFFTAG_GROUP4OPTIONS,	 1, 1,	TIFF_LONG,	FIELD_OPTIONS,
      FALSE,	FALSE,	"Group4Options" },
};
#define	N(a)	(sizeof (a) / sizeof (a[0]))

static int
Fax3VSetField(TIFF* tif, ttag_t tag, va_list ap)
{
	Fax3BaseState* sp = Fax3State(tif);

	switch (tag) {
	case TIFFTAG_FAXMODE:
		sp->mode = va_arg(ap, int);
		return (1);			/* NB: pseudo tag */
	case TIFFTAG_FAXFILLFUNC:
		if (sp->rw_mode == O_RDONLY)
			DecoderState(tif)->fill = va_arg(ap, TIFFFaxFillFunc);
		return (1);			/* NB: pseudo tag */
	case TIFFTAG_GROUP3OPTIONS:
	case TIFFTAG_GROUP4OPTIONS:
		sp->groupoptions = va_arg(ap, uint32);
		break;
	case TIFFTAG_BADFAXLINES:
		sp->badfaxlines = va_arg(ap, uint32);
		break;
	case TIFFTAG_CLEANFAXDATA:
		sp->cleanfaxdata = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_CONSECUTIVEBADFAXLINES:
		sp->badfaxrun = va_arg(ap, uint32);
		break;
	case TIFFTAG_FAXRECVPARAMS:
		sp->recvparams = va_arg(ap, uint32);
		break;
	case TIFFTAG_FAXSUBADDRESS:
		_TIFFsetString(&sp->subaddress, va_arg(ap, char*));
		break;
	case TIFFTAG_FAXRECVTIME:
		sp->recvtime = va_arg(ap, uint32);
		break;
	default:
		return (*sp->vsetparent)(tif, tag, ap);
	}
	TIFFSetFieldBit(tif, _TIFFFieldWithTag(tif, tag)->field_bit);
	tif->tif_flags |= TIFF_DIRTYDIRECT;
	return (1);
}

static int
Fax3VGetField(TIFF* tif, ttag_t tag, va_list ap)
{
	Fax3BaseState* sp = Fax3State(tif);

	switch (tag) {
	case TIFFTAG_FAXMODE:
		*va_arg(ap, int*) = sp->mode;
		break;
	case TIFFTAG_FAXFILLFUNC:
		if (sp->rw_mode == O_RDONLY)
			*va_arg(ap, TIFFFaxFillFunc*) = DecoderState(tif)->fill;
		break;
	case TIFFTAG_GROUP3OPTIONS:
	case TIFFTAG_GROUP4OPTIONS:
		*va_arg(ap, uint32*) = sp->groupoptions;
		break;
	case TIFFTAG_BADFAXLINES:
		*va_arg(ap, uint32*) = sp->badfaxlines;
		break;
	case TIFFTAG_CLEANFAXDATA:
		*va_arg(ap, uint16*) = sp->cleanfaxdata;
		break;
	case TIFFTAG_CONSECUTIVEBADFAXLINES:
		*va_arg(ap, uint32*) = sp->badfaxrun;
		break;
	case TIFFTAG_FAXRECVPARAMS:
		*va_arg(ap, uint32*) = sp->recvparams;
		break;
	case TIFFTAG_FAXSUBADDRESS:
		*va_arg(ap, char**) = sp->subaddress;
		break;
	case TIFFTAG_FAXRECVTIME:
		*va_arg(ap, uint32*) = sp->recvtime;
		break;
	default:
		return (*sp->vgetparent)(tif, tag, ap);
	}
	return (1);
}

static void
Fax3PrintDir(TIFF* tif, FILE* fd, long flags)
{
	Fax3BaseState* sp = Fax3State(tif);

	(void) flags;
	if (TIFFFieldSet(tif,FIELD_OPTIONS)) {
		const char* sep = " ";
		if (tif->tif_dir.td_compression == COMPRESSION_CCITTFAX4) {
			fprintf(fd, "  Group 4 Options:");
			if (sp->groupoptions & GROUP4OPT_UNCOMPRESSED)
				fprintf(fd, "%suncompressed data", sep);
		} else {

			fprintf(fd, "  Group 3 Options:");
			if (sp->groupoptions & GROUP3OPT_2DENCODING)
				fprintf(fd, "%s2-d encoding", sep), sep = "+";
			if (sp->groupoptions & GROUP3OPT_FILLBITS)
				fprintf(fd, "%sEOL padding", sep), sep = "+";
			if (sp->groupoptions & GROUP3OPT_UNCOMPRESSED)
				fprintf(fd, "%suncompressed data", sep);
		}
		fprintf(fd, " (%lu = 0x%lx)\n",
		    (u_long) sp->groupoptions, (u_long) sp->groupoptions);
	}
	if (TIFFFieldSet(tif,FIELD_CLEANFAXDATA)) {
		fprintf(fd, "  Fax Data:");
		switch (sp->cleanfaxdata) {
		case CLEANFAXDATA_CLEAN:
			fprintf(fd, " clean");
			break;
		case CLEANFAXDATA_REGENERATED:
			fprintf(fd, " receiver regenerated");
			break;
		case CLEANFAXDATA_UNCLEAN:
			fprintf(fd, " uncorrected errors");
			break;
		}
		fprintf(fd, " (%u = 0x%x)\n",
		    sp->cleanfaxdata, sp->cleanfaxdata);
	}
	if (TIFFFieldSet(tif,FIELD_BADFAXLINES))
		fprintf(fd, "  Bad Fax Lines: %lu\n", (u_long) sp->badfaxlines);
	if (TIFFFieldSet(tif,FIELD_BADFAXRUN))
		fprintf(fd, "  Consecutive Bad Fax Lines: %lu\n",
		    (u_long) sp->badfaxrun);
	if (TIFFFieldSet(tif,FIELD_RECVPARAMS))
		fprintf(fd, "  Fax Receive Parameters: %08lx\n",
		   (u_long) sp->recvparams);
	if (TIFFFieldSet(tif,FIELD_SUBADDRESS))
		fprintf(fd, "  Fax SubAddress: %s\n", sp->subaddress);
	if (TIFFFieldSet(tif,FIELD_RECVTIME))
		fprintf(fd, "  Fax Receive Time: %lu secs\n",
		    (u_long) sp->recvtime);
}

static int
InitCCITTFax3(TIFF* tif)
{
	Fax3BaseState* sp;

	/*
	 * Allocate state block so tag methods have storage to record values.
	 */
	if (tif->tif_mode == O_RDONLY)
		tif->tif_data = (tidata_t)
                    _TIFFmalloc(sizeof (Fax3DecodeState));
	else
		tif->tif_data = (tidata_t)
                    _TIFFmalloc(sizeof (Fax3EncodeState));

	if (tif->tif_data == NULL) {
		TIFFError("TIFFInitCCITTFax3",
		    "%s: No space for state block", tif->tif_name);
		return (0);
	}

	sp = Fax3State(tif);
        sp->rw_mode = tif->tif_mode;

	/*
	 * Merge codec-specific tag information and
	 * override parent get/set field methods.
	 */
	_TIFFMergeFieldInfo(tif, faxFieldInfo, N(faxFieldInfo));
	sp->vgetparent = tif->tif_vgetfield;
	tif->tif_vgetfield = Fax3VGetField;	/* hook for codec tags */
	sp->vsetparent = tif->tif_vsetfield;
	tif->tif_vsetfield = Fax3VSetField;	/* hook for codec tags */
	tif->tif_printdir = Fax3PrintDir;	/* hook for codec tags */
	sp->groupoptions = 0;	
	sp->recvparams = 0;
	sp->subaddress = NULL;

	if (sp->rw_mode == O_RDONLY) {
		tif->tif_flags |= TIFF_NOBITREV;/* decoder does bit reversal */
		DecoderState(tif)->runs = NULL;
		TIFFSetField(tif, TIFFTAG_FAXFILLFUNC, _TIFFFax3fillruns);
	} else
		EncoderState(tif)->refline = NULL;

	/*
	 * Install codec methods.
	 */
	tif->tif_setupdecode = Fax3SetupState;
	tif->tif_predecode = Fax3PreDecode;
	tif->tif_decoderow = Fax3Decode1D;
	tif->tif_decodestrip = Fax3Decode1D;
	tif->tif_decodetile = Fax3Decode1D;
	tif->tif_setupencode = Fax3SetupState;
	tif->tif_preencode = Fax3PreEncode;
	tif->tif_postencode = Fax3PostEncode;
	tif->tif_encoderow = Fax3Encode;
	tif->tif_encodestrip = Fax3Encode;
	tif->tif_encodetile = Fax3Encode;
	tif->tif_close = Fax3Close;
	tif->tif_cleanup = Fax3Cleanup;

	return (1);
}

int
TIFFInitCCITTFax3(TIFF* tif, int scheme)
{
	if (InitCCITTFax3(tif)) {
		_TIFFMergeFieldInfo(tif, fax3FieldInfo, N(fax3FieldInfo));

		/*
		 * The default format is Class/F-style w/o RTC.
		 */
		return TIFFSetField(tif, TIFFTAG_FAXMODE, FAXMODE_CLASSF);
	} else
		return (0);
}

/*
 * CCITT Group 4 (T.6) Facsimile-compatible
 * Compression Scheme Support.
 */

#define	SWAP(t,a,b)	{ t x; x = (a); (a) = (b); (b) = x; }
/*
 * Decode the requested amount of G4-encoded data.
 */
static int
Fax4Decode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
{
	DECLARE_STATE_2D(tif, sp, "Fax4Decode");

	(void) s;
	CACHE_STATE(tif, sp);
	while ((long)occ > 0) {
		a0 = 0;
		RunLength = 0;
		pa = thisrun = sp->curruns;
		pb = sp->refruns;
		b1 = *pb++;
#ifdef FAX3_DEBUG
		printf("\nBitAcc=%08X, BitsAvail = %d\n", BitAcc, BitsAvail);
		printf("-------------------- %d\n", tif->tif_row);
		fflush(stdout);
#endif
		EXPAND2D(EOFG4);
                if (EOLcnt)
                    goto EOFG4;
		(*sp->fill)(buf, thisrun, pa, lastx);
		SETVAL(0);		/* imaginary change for reference */
		SWAP(uint32*, sp->curruns, sp->refruns);
		buf += sp->b.rowbytes;
		occ -= sp->b.rowbytes;
		if (occ != 0)
			tif->tif_row++;
		continue;
	EOFG4:
                NeedBits16( 13, BADG4 );
        BADG4:
#ifdef FAX3_DEBUG
                if( GetBits(13) != 0x1001 )
                    fputs( "Bad RTC\n", stderr );
#endif                
                ClrBits( 13 );
		(*sp->fill)(buf, thisrun, pa, lastx);
		UNCACHE_STATE(tif, sp);
		return (-1);
	}
	UNCACHE_STATE(tif, sp);
	return (1);
}
#undef	SWAP

/*
 * Encode the requested amount of data.
 */
static int
Fax4Encode(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)
{
	Fax3EncodeState *sp = EncoderState(tif);

	(void) s;
	while ((long)cc > 0) {
		if (!Fax3Encode2DRow(tif, bp, sp->refline, sp->b.rowpixels))
			return (0);
		_TIFFmemcpy(sp->refline, bp, sp->b.rowbytes);
		bp += sp->b.rowbytes;
		cc -= sp->b.rowbytes;
		if (cc != 0)
			tif->tif_row++;
	}
	return (1);
}

static int
Fax4PostEncode(TIFF* tif)
{
	Fax3EncodeState *sp = EncoderState(tif);

	/* terminate strip w/ EOFB */
	Fax3PutBits(tif, EOL, 12);
	Fax3PutBits(tif, EOL, 12);
	if (sp->bit != 8)
		Fax3FlushBits(tif, sp);
	return (1);
}

int
TIFFInitCCITTFax4(TIFF* tif, int scheme)
{
	if (InitCCITTFax3(tif)) {		/* reuse G3 support */
		_TIFFMergeFieldInfo(tif, fax4FieldInfo, N(fax4FieldInfo));

		tif->tif_decoderow = Fax4Decode;
		tif->tif_decodestrip = Fax4Decode;
		tif->tif_decodetile = Fax4Decode;
		tif->tif_encoderow = Fax4Encode;
		tif->tif_encodestrip = Fax4Encode;
		tif->tif_encodetile = Fax4Encode;
		tif->tif_postencode = Fax4PostEncode;
		/*
		 * Suppress RTC at the end of each strip.
		 */
		return TIFFSetField(tif, TIFFTAG_FAXMODE, FAXMODE_NORTC);
	} else
		return (0);
}

/*
 * CCITT Group 3 1-D Modified Huffman RLE Compression Support.
 * (Compression algorithms 2 and 32771)
 */

/*
 * Decode the requested amount of RLE-encoded data.
 */
static int
Fax3DecodeRLE(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
{
	DECLARE_STATE(tif, sp, "Fax3DecodeRLE");
	int mode = sp->b.mode;

	(void) s;
	CACHE_STATE(tif, sp);
	thisrun = sp->curruns;
	while ((long)occ > 0) {
		a0 = 0;
		RunLength = 0;
		pa = thisrun;
#ifdef FAX3_DEBUG
		printf("\nBitAcc=%08X, BitsAvail = %d\n", BitAcc, BitsAvail);
		printf("-------------------- %d\n", tif->tif_row);
		fflush(stdout);
#endif
		EXPAND1D(EOFRLE);
		(*sp->fill)(buf, thisrun, pa, lastx);
		/*
		 * Cleanup at the end of the row.
		 */
		if (mode & FAXMODE_BYTEALIGN) {
			int n = BitsAvail - (BitsAvail &~ 7);
			ClrBits(n);
		} else if (mode & FAXMODE_WORDALIGN) {
			int n = BitsAvail - (BitsAvail &~ 15);
			ClrBits(n);
			if (BitsAvail == 0 && !isAligned(cp, uint16))
			    cp++;
		}
		buf += sp->b.rowbytes;
		occ -= sp->b.rowbytes;
		if (occ != 0)
			tif->tif_row++;
		continue;
	EOFRLE:				/* premature EOF */
		(*sp->fill)(buf, thisrun, pa, lastx);
		UNCACHE_STATE(tif, sp);
		return (-1);
	}
	UNCACHE_STATE(tif, sp);
	return (1);
}

int
TIFFInitCCITTRLE(TIFF* tif, int scheme)
{
	if (InitCCITTFax3(tif)) {		/* reuse G3 support */
		tif->tif_decoderow = Fax3DecodeRLE;
		tif->tif_decodestrip = Fax3DecodeRLE;
		tif->tif_decodetile = Fax3DecodeRLE;
		/*
		 * Suppress RTC+EOLs when encoding and byte-align data.
		 */
		return TIFFSetField(tif, TIFFTAG_FAXMODE,
		    FAXMODE_NORTC|FAXMODE_NOEOL|FAXMODE_BYTEALIGN);
	} else
		return (0);
}

int
TIFFInitCCITTRLEW(TIFF* tif, int scheme)
{
	if (InitCCITTFax3(tif)) {		/* reuse G3 support */
		tif->tif_decoderow = Fax3DecodeRLE;
		tif->tif_decodestrip = Fax3DecodeRLE;
		tif->tif_decodetile = Fax3DecodeRLE;
		/*
		 * Suppress RTC+EOLs when encoding and word-align data.
		 */
		return TIFFSetField(tif, TIFFTAG_FAXMODE,
		    FAXMODE_NORTC|FAXMODE_NOEOL|FAXMODE_WORDALIGN);
	} else
		return (0);
}
#endif /* CCITT_SUPPORT */