[wxWidgets.git] / src / tiff / libtiff / tif_packbits.c

/* $Id$ */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

#include "tiffiop.h"
#ifdef PACKBITS_SUPPORT
/*
 * TIFF Library.
 *
 * PackBits Compression Algorithm Support
 */
#include <stdio.h>

static int
PackBitsPreEncode(TIFF* tif, uint16 s)
{
	(void) s;

	if (!(tif->tif_data = (uint8*)_TIFFmalloc(sizeof(tmsize_t))))
		return (0);
	/*
	 * Calculate the scanline/tile-width size in bytes.
	 */
	if (isTiled(tif))
		*(tmsize_t*)tif->tif_data = TIFFTileRowSize(tif);
	else
		*(tmsize_t*)tif->tif_data = TIFFScanlineSize(tif);
	return (1);
}

static int
PackBitsPostEncode(TIFF* tif)
{
        if (tif->tif_data)
            _TIFFfree(tif->tif_data);
	return (1);
}

/*
 * Encode a run of pixels.
 */
static int
PackBitsEncode(TIFF* tif, uint8* buf, tmsize_t cc, uint16 s)
{
	unsigned char* bp = (unsigned char*) buf;
	uint8* op;
	uint8* ep;
	uint8* lastliteral;
	long n, slop;
	int b;
	enum { BASE, LITERAL, RUN, LITERAL_RUN } state;

	(void) s;
	op = tif->tif_rawcp;
	ep = tif->tif_rawdata + tif->tif_rawdatasize;
	state = BASE;
	lastliteral = 0;
	while (cc > 0) {
		/*
		 * Find the longest string of identical bytes.
		 */
		b = *bp++, cc--, n = 1;
		for (; cc > 0 && b == *bp; cc--, bp++)
			n++;
	again:
		if (op + 2 >= ep) {		/* insure space for new data */
			/*
			 * Be careful about writing the last
			 * literal.  Must write up to that point
			 * and then copy the remainder to the
			 * front of the buffer.
			 */
			if (state == LITERAL || state == LITERAL_RUN) {
				slop = (long)(op - lastliteral);
				tif->tif_rawcc += (tmsize_t)(lastliteral - tif->tif_rawcp);
				if (!TIFFFlushData1(tif))
					return (-1);
				op = tif->tif_rawcp;
				while (slop-- > 0)
					*op++ = *lastliteral++;
				lastliteral = tif->tif_rawcp;
			} else {
				tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
				if (!TIFFFlushData1(tif))
					return (-1);
				op = tif->tif_rawcp;
			}
		}
		switch (state) {
		case BASE:		/* initial state, set run/literal */
			if (n > 1) {
				state = RUN;
				if (n > 128) {
					*op++ = (uint8) -127;
					*op++ = (uint8) b;
					n -= 128;
					goto again;
				}
				*op++ = (uint8)(-(n-1));
				*op++ = (uint8) b;
			} else {
				lastliteral = op;
				*op++ = 0;
				*op++ = (uint8) b;
				state = LITERAL;
			}
			break;
		case LITERAL:		/* last object was literal string */
			if (n > 1) {
				state = LITERAL_RUN;
				if (n > 128) {
					*op++ = (uint8) -127;
					*op++ = (uint8) b;
					n -= 128;
					goto again;
				}
				*op++ = (uint8)(-(n-1));	/* encode run */
				*op++ = (uint8) b;
			} else {			/* extend literal */
				if (++(*lastliteral) == 127)
					state = BASE;
				*op++ = (uint8) b;
			}
			break;
		case RUN:		/* last object was run */
			if (n > 1) {
				if (n > 128) {
					*op++ = (uint8) -127;
					*op++ = (uint8) b;
					n -= 128;
					goto again;
				}
				*op++ = (uint8)(-(n-1));
				*op++ = (uint8) b;
			} else {
				lastliteral = op;
				*op++ = 0;
				*op++ = (uint8) b;
				state = LITERAL;
			}
			break;
		case LITERAL_RUN:	/* literal followed by a run */
			/*
			 * Check to see if previous run should
			 * be converted to a literal, in which
			 * case we convert literal-run-literal
			 * to a single literal.
			 */
			if (n == 1 && op[-2] == (uint8) -1 &&
			    *lastliteral < 126) {
				state = (((*lastliteral) += 2) == 127 ?
				    BASE : LITERAL);
				op[-2] = op[-1];	/* replicate */
			} else
				state = RUN;
			goto again;
		}
	}
	tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
	tif->tif_rawcp = op;
	return (1);
}

/*
 * Encode a rectangular chunk of pixels.  We break it up
 * into row-sized pieces to insure that encoded runs do
 * not span rows.  Otherwise, there can be problems with
 * the decoder if data is read, for example, by scanlines
 * when it was encoded by strips.
 */
static int
PackBitsEncodeChunk(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
{
	tmsize_t rowsize = *(tmsize_t*)tif->tif_data;

	while (cc > 0) {
		tmsize_t chunk = rowsize;
		
		if( cc < chunk )
		    chunk = cc;

		if (PackBitsEncode(tif, bp, chunk, s) < 0)
		    return (-1);
		bp += chunk;
		cc -= chunk;
	}
	return (1);
}

static int
PackBitsDecode(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
{
	static const char module[] = "PackBitsDecode";
	char *bp;
	tmsize_t cc;
	long n;
	int b;

	(void) s;
	bp = (char*) tif->tif_rawcp;
	cc = tif->tif_rawcc;
	while (cc > 0 && occ > 0) {
		n = (long) *bp++, cc--;
		/*
		 * Watch out for compilers that
		 * don't sign extend chars...
		 */
		if (n >= 128)
			n -= 256;
		if (n < 0) {		/* replicate next byte -n+1 times */
			if (n == -128)	/* nop */
				continue;
			n = -n + 1;
			if( occ < (tmsize_t)n )
			{
				TIFFWarningExt(tif->tif_clientdata, module,
				    "Discarding %lu bytes to avoid buffer overrun",
				    (unsigned long) ((tmsize_t)n - occ));
				n = (long)occ;
			}
			occ -= n;
			b = *bp++, cc--;
			while (n-- > 0)
				*op++ = (uint8) b;
		} else {		/* copy next n+1 bytes literally */
			if (occ < (tmsize_t)(n + 1))
			{
				TIFFWarningExt(tif->tif_clientdata, module,
				    "Discarding %lu bytes to avoid buffer overrun",
				    (unsigned long) ((tmsize_t)n - occ + 1));
				n = (long)occ - 1;
			}
			if (cc < (tmsize_t) (n+1)) 
			{
				TIFFWarningExt(tif->tif_clientdata, module,
					       "Terminating PackBitsDecode due to lack of data.");
				break;
			}
			_TIFFmemcpy(op, bp, ++n);
			op += n; occ -= n;
			bp += n; cc -= n;
		}
	}
	tif->tif_rawcp = (uint8*) bp;
	tif->tif_rawcc = cc;
	if (occ > 0) {
		TIFFErrorExt(tif->tif_clientdata, module,
		    "Not enough data for scanline %lu",
		    (unsigned long) tif->tif_row);
		return (0);
	}
	return (1);
}

int
TIFFInitPackBits(TIFF* tif, int scheme)
{
	(void) scheme;
	tif->tif_decoderow = PackBitsDecode;
	tif->tif_decodestrip = PackBitsDecode;
	tif->tif_decodetile = PackBitsDecode;
	tif->tif_preencode = PackBitsPreEncode;
	tif->tif_postencode = PackBitsPostEncode;
	tif->tif_encoderow = PackBitsEncode;
	tif->tif_encodestrip = PackBitsEncodeChunk;
	tif->tif_encodetile = PackBitsEncodeChunk;
	return (1);
}
#endif /* PACKBITS_SUPPORT */

/* vim: set ts=8 sts=8 sw=8 noet: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */
Commit	Line	Data
8414a40c VZ	1	/* $Id$ */
	2
	3	/*
	4	* Copyright (c) 1988-1997 Sam Leffler
	5	* Copyright (c) 1991-1997 Silicon Graphics, Inc.
	6	*
	7	* Permission to use, copy, modify, distribute, and sell this software and
	8	* its documentation for any purpose is hereby granted without fee, provided
	9	* that (i) the above copyright notices and this permission notice appear in
	10	* all copies of the software and related documentation, and (ii) the names of
	11	* Sam Leffler and Silicon Graphics may not be used in any advertising or
	12	* publicity relating to the software without the specific, prior written
	13	* permission of Sam Leffler and Silicon Graphics.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	16	* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	17	* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	18	*
	19	* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	20	* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	21	* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	22	* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	23	* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	24	* OF THIS SOFTWARE.
	25	*/
	26
	27	#include "tiffiop.h"
	28	#ifdef PACKBITS_SUPPORT
	29	/*
	30	* TIFF Library.
	31	*
	32	* PackBits Compression Algorithm Support
	33	*/
	34	#include <stdio.h>
	35
	36	static int
80ed523f	37	PackBitsPreEncode(TIFF* tif, uint16 s)
8414a40c VZ	38	{
	39	(void) s;
	40
80ed523f	41	if (!(tif->tif_data = (uint8*)_TIFFmalloc(sizeof(tmsize_t))))
8414a40c VZ	42	return (0);
	43	/*
	44	* Calculate the scanline/tile-width size in bytes.
	45	*/
	46	if (isTiled(tif))
80ed523f	47	(tmsize_t)tif->tif_data = TIFFTileRowSize(tif);
8414a40c	48	else
80ed523f	49	(tmsize_t)tif->tif_data = TIFFScanlineSize(tif);
8414a40c VZ	50	return (1);
	51	}
	52
	53	static int
	54	PackBitsPostEncode(TIFF* tif)
	55	{
	56	if (tif->tif_data)
	57	_TIFFfree(tif->tif_data);
	58	return (1);
	59	}
	60
8414a40c VZ	61	/*
	62	* Encode a run of pixels.
	63	*/
	64	static int
80ed523f	65	PackBitsEncode(TIFF* tif, uint8* buf, tmsize_t cc, uint16 s)
8414a40c VZ	66	{
8414a40c VZ	67	unsigned char* bp = (unsigned char*) buf;
80ed523f VZ	68	uint8* op;
	69	uint8* ep;
	70	uint8* lastliteral;
8414a40c VZ	71	long n, slop;
	72	int b;
	73	enum { BASE, LITERAL, RUN, LITERAL_RUN } state;
	74
	75	(void) s;
	76	op = tif->tif_rawcp;
	77	ep = tif->tif_rawdata + tif->tif_rawdatasize;
	78	state = BASE;
	79	lastliteral = 0;
	80	while (cc > 0) {
	81	/*
	82	* Find the longest string of identical bytes.
	83	*/
	84	b = *bp++, cc--, n = 1;
	85	for (; cc > 0 && b == *bp; cc--, bp++)
	86	n++;
	87	again:
	88	if (op + 2 >= ep) { /* insure space for new data */
	89	/*
	90	* Be careful about writing the last
	91	* literal. Must write up to that point
	92	* and then copy the remainder to the
	93	* front of the buffer.
	94	*/
	95	if (state == LITERAL \|\| state == LITERAL_RUN) {
80ed523f VZ	96	slop = (long)(op - lastliteral);
80ed523f VZ	97	tif->tif_rawcc += (tmsize_t)(lastliteral - tif->tif_rawcp);
8414a40c VZ	98	if (!TIFFFlushData1(tif))
	99	return (-1);
	100	op = tif->tif_rawcp;
	101	while (slop-- > 0)
	102	op++ = lastliteral++;
	103	lastliteral = tif->tif_rawcp;
	104	} else {
80ed523f	105	tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
8414a40c VZ	106	if (!TIFFFlushData1(tif))
	107	return (-1);
	108	op = tif->tif_rawcp;
	109	}
	110	}
	111	switch (state) {
	112	case BASE: /* initial state, set run/literal */
	113	if (n > 1) {
	114	state = RUN;
	115	if (n > 128) {
80ed523f VZ	116	*op++ = (uint8) -127;
80ed523f VZ	117	*op++ = (uint8) b;
8414a40c VZ	118	n -= 128;
	119	goto again;
	120	}
80ed523f VZ	121	*op++ = (uint8)(-(n-1));
80ed523f VZ	122	*op++ = (uint8) b;
8414a40c VZ	123	} else {
	124	lastliteral = op;
	125	*op++ = 0;
80ed523f	126	*op++ = (uint8) b;
8414a40c VZ	127	state = LITERAL;
	128	}
	129	break;
	130	case LITERAL: /* last object was literal string */
	131	if (n > 1) {
	132	state = LITERAL_RUN;
	133	if (n > 128) {
80ed523f VZ	134	*op++ = (uint8) -127;
80ed523f VZ	135	*op++ = (uint8) b;
8414a40c VZ	136	n -= 128;
	137	goto again;
	138	}
80ed523f VZ	139	op++ = (uint8)(-(n-1)); / encode run */
80ed523f VZ	140	*op++ = (uint8) b;
8414a40c VZ	141	} else { /* extend literal */
	142	if (++(*lastliteral) == 127)
	143	state = BASE;
80ed523f	144	*op++ = (uint8) b;
8414a40c VZ	145	}
	146	break;
	147	case RUN: /* last object was run */
	148	if (n > 1) {
	149	if (n > 128) {
80ed523f VZ	150	*op++ = (uint8) -127;
80ed523f VZ	151	*op++ = (uint8) b;
8414a40c VZ	152	n -= 128;
	153	goto again;
	154	}
80ed523f VZ	155	*op++ = (uint8)(-(n-1));
80ed523f VZ	156	*op++ = (uint8) b;
8414a40c VZ	157	} else {
	158	lastliteral = op;
	159	*op++ = 0;
80ed523f	160	*op++ = (uint8) b;
8414a40c VZ	161	state = LITERAL;
	162	}
	163	break;
	164	case LITERAL_RUN: /* literal followed by a run */
	165	/*
	166	* Check to see if previous run should
	167	* be converted to a literal, in which
	168	* case we convert literal-run-literal
	169	* to a single literal.
	170	*/
80ed523f	171	if (n == 1 && op[-2] == (uint8) -1 &&
8414a40c VZ	172	*lastliteral < 126) {
	173	state = (((*lastliteral) += 2) == 127 ?
	174	BASE : LITERAL);
	175	op[-2] = op[-1]; /* replicate */
	176	} else
	177	state = RUN;
	178	goto again;
	179	}
	180	}
80ed523f	181	tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
8414a40c VZ	182	tif->tif_rawcp = op;
	183	return (1);
	184	}
	185
	186	/*
	187	* Encode a rectangular chunk of pixels. We break it up
	188	* into row-sized pieces to insure that encoded runs do
	189	* not span rows. Otherwise, there can be problems with
	190	* the decoder if data is read, for example, by scanlines
	191	* when it was encoded by strips.
	192	*/
	193	static int
80ed523f	194	PackBitsEncodeChunk(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
8414a40c	195	{
80ed523f	196	tmsize_t rowsize = (tmsize_t)tif->tif_data;
8414a40c	197
80ed523f VZ	198	while (cc > 0) {
80ed523f VZ	199	tmsize_t chunk = rowsize;
8414a40c VZ	200
	201	if( cc < chunk )
	202	chunk = cc;
	203
	204	if (PackBitsEncode(tif, bp, chunk, s) < 0)
	205	return (-1);
	206	bp += chunk;
	207	cc -= chunk;
	208	}
	209	return (1);
	210	}
	211
	212	static int
80ed523f	213	PackBitsDecode(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
8414a40c	214	{
80ed523f	215	static const char module[] = "PackBitsDecode";
8414a40c	216	char *bp;
80ed523f	217	tmsize_t cc;
8414a40c VZ	218	long n;
	219	int b;
	220
	221	(void) s;
	222	bp = (char*) tif->tif_rawcp;
	223	cc = tif->tif_rawcc;
80ed523f	224	while (cc > 0 && occ > 0) {
8414a40c VZ	225	n = (long) *bp++, cc--;
	226	/*
	227	* Watch out for compilers that
	228	* don't sign extend chars...
	229	*/
	230	if (n >= 128)
	231	n -= 256;
	232	if (n < 0) { /* replicate next byte -n+1 times */
	233	if (n == -128) /* nop */
	234	continue;
80ed523f VZ	235	n = -n + 1;
	236	if( occ < (tmsize_t)n )
	237	{
	238	TIFFWarningExt(tif->tif_clientdata, module,
	239	"Discarding %lu bytes to avoid buffer overrun",
	240	(unsigned long) ((tmsize_t)n - occ));
	241	n = (long)occ;
	242	}
8414a40c VZ	243	occ -= n;
	244	b = *bp++, cc--;
	245	while (n-- > 0)
80ed523f	246	*op++ = (uint8) b;
8414a40c	247	} else { /* copy next n+1 bytes literally */
80ed523f VZ	248	if (occ < (tmsize_t)(n + 1))
	249	{
	250	TIFFWarningExt(tif->tif_clientdata, module,
	251	"Discarding %lu bytes to avoid buffer overrun",
	252	(unsigned long) ((tmsize_t)n - occ + 1));
	253	n = (long)occ - 1;
	254	}
	255	if (cc < (tmsize_t) (n+1))
	256	{
	257	TIFFWarningExt(tif->tif_clientdata, module,
	258	"Terminating PackBitsDecode due to lack of data.");
	259	break;
	260	}
	261	_TIFFmemcpy(op, bp, ++n);
8414a40c VZ	262	op += n; occ -= n;
	263	bp += n; cc -= n;
	264	}
	265	}
80ed523f	266	tif->tif_rawcp = (uint8*) bp;
8414a40c VZ	267	tif->tif_rawcc = cc;
8414a40c VZ	268	if (occ > 0) {
80ed523f VZ	269	TIFFErrorExt(tif->tif_clientdata, module,
	270	"Not enough data for scanline %lu",
	271	(unsigned long) tif->tif_row);
8414a40c VZ	272	return (0);
	273	}
	274	return (1);
	275	}
	276
	277	int
	278	TIFFInitPackBits(TIFF* tif, int scheme)
	279	{
	280	(void) scheme;
	281	tif->tif_decoderow = PackBitsDecode;
	282	tif->tif_decodestrip = PackBitsDecode;
	283	tif->tif_decodetile = PackBitsDecode;
	284	tif->tif_preencode = PackBitsPreEncode;
80ed523f	285	tif->tif_postencode = PackBitsPostEncode;
8414a40c VZ	286	tif->tif_encoderow = PackBitsEncode;
	287	tif->tif_encodestrip = PackBitsEncodeChunk;
	288	tif->tif_encodetile = PackBitsEncodeChunk;
	289	return (1);
	290	}
	291	#endif /* PACKBITS_SUPPORT */
	292
	293	/* vim: set ts=8 sts=8 sw=8 noet: */
80ed523f VZ	294	/*
	295	* Local Variables:
	296	* mode: c
	297	* c-basic-offset: 8
	298	* fill-column: 78
	299	* End:
	300	*/