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, tsample_t s)
{
	(void) s;

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

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

/*
 * NB: tidata is the type representing *(tidata_t);
 *     if tidata_t is made signed then this type must
 *     be adjusted accordingly.
 */
typedef unsigned char tidata;

/*
 * Encode a run of pixels.
 */
static int
PackBitsEncode(TIFF* tif, tidata_t buf, tsize_t cc, tsample_t s)
{
	unsigned char* bp = (unsigned char*) buf;
	tidata_t op, ep, 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 = op - lastliteral;
				tif->tif_rawcc += 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 += 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++ = (tidata) -127;
					*op++ = (tidataval_t) b;
					n -= 128;
					goto again;
				}
				*op++ = (tidataval_t)(-(n-1));
				*op++ = (tidataval_t) b;
			} else {
				lastliteral = op;
				*op++ = 0;
				*op++ = (tidataval_t) b;
				state = LITERAL;
			}
			break;
		case LITERAL:		/* last object was literal string */
			if (n > 1) {
				state = LITERAL_RUN;
				if (n > 128) {
					*op++ = (tidata) -127;
					*op++ = (tidataval_t) b;
					n -= 128;
					goto again;
				}
				*op++ = (tidataval_t)(-(n-1));	/* encode run */
				*op++ = (tidataval_t) b;
			} else {			/* extend literal */
				if (++(*lastliteral) == 127)
					state = BASE;
				*op++ = (tidataval_t) b;
			}
			break;
		case RUN:		/* last object was run */
			if (n > 1) {
				if (n > 128) {
					*op++ = (tidata) -127;
					*op++ = (tidataval_t) b;
					n -= 128;
					goto again;
				}
				*op++ = (tidataval_t)(-(n-1));
				*op++ = (tidataval_t) b;
			} else {
				lastliteral = op;
				*op++ = 0;
				*op++ = (tidataval_t) 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] == (tidata) -1 &&
			    *lastliteral < 126) {
				state = (((*lastliteral) += 2) == 127 ?
				    BASE : LITERAL);
				op[-2] = op[-1];	/* replicate */
			} else
				state = RUN;
			goto again;
		}
	}
	tif->tif_rawcc += 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, tidata_t bp, tsize_t cc, tsample_t s)
{
	tsize_t rowsize = *(tsize_t*)tif->tif_data;

	while ((long)cc > 0) {
		int	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, tidata_t op, tsize_t occ, tsample_t s)
{
	char *bp;
	tsize_t cc;
	long n;
	int b;

	(void) s;
	bp = (char*) tif->tif_rawcp;
	cc = tif->tif_rawcc;
	while (cc > 0 && (long)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 < n )
                        {
							TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
                                        "PackBitsDecode: discarding %d bytes "
                                        "to avoid buffer overrun",
                                        n - occ);
                            n = occ;
                        }
			occ -= n;
			b = *bp++, cc--;
			while (n-- > 0)
				*op++ = (tidataval_t) b;
		} else {		/* copy next n+1 bytes literally */
			if (occ < n + 1)
                        {
                            TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
                                        "PackBitsDecode: discarding %d bytes "
                                        "to avoid buffer overrun",
                                        n - occ + 1);
                            n = occ - 1;
                        }
                        _TIFFmemcpy(op, bp, ++n);
			op += n; occ -= n;
			bp += n; cc -= n;
		}
	}
	tif->tif_rawcp = (tidata_t) bp;
	tif->tif_rawcc = cc;
	if (occ > 0) {
		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
		    "PackBitsDecode: Not enough data for scanline %ld",
		    (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: */
Commit	Line	Data
	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
	37	PackBitsPreEncode(TIFF* tif, tsample_t s)
	38	{
	39	(void) s;
	40
	41	if (!(tif->tif_data = (tidata_t)_TIFFmalloc(sizeof(tsize_t))))
	42	return (0);
	43	/*
	44	* Calculate the scanline/tile-width size in bytes.
	45	*/
	46	if (isTiled(tif))
	47	(tsize_t)tif->tif_data = TIFFTileRowSize(tif);
	48	else
	49	(tsize_t)tif->tif_data = TIFFScanlineSize(tif);
	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
	61	/*
	62	* NB: tidata is the type representing *(tidata_t);
	63	* if tidata_t is made signed then this type must
	64	* be adjusted accordingly.
	65	*/
	66	typedef unsigned char tidata;
	67
	68	/*
	69	* Encode a run of pixels.
	70	*/
	71	static int
	72	PackBitsEncode(TIFF* tif, tidata_t buf, tsize_t cc, tsample_t s)
	73	{
	74	unsigned char* bp = (unsigned char*) buf;
	75	tidata_t op, ep, lastliteral;
	76	long n, slop;
	77	int b;
	78	enum { BASE, LITERAL, RUN, LITERAL_RUN } state;
	79
	80	(void) s;
	81	op = tif->tif_rawcp;
	82	ep = tif->tif_rawdata + tif->tif_rawdatasize;
	83	state = BASE;
	84	lastliteral = 0;
	85	while (cc > 0) {
	86	/*
	87	* Find the longest string of identical bytes.
	88	*/
	89	b = *bp++, cc--, n = 1;
	90	for (; cc > 0 && b == *bp; cc--, bp++)
	91	n++;
	92	again:
	93	if (op + 2 >= ep) { /* insure space for new data */
	94	/*
	95	* Be careful about writing the last
	96	* literal. Must write up to that point
	97	* and then copy the remainder to the
	98	* front of the buffer.
	99	*/
	100	if (state == LITERAL \|\| state == LITERAL_RUN) {
	101	slop = op - lastliteral;
	102	tif->tif_rawcc += lastliteral - tif->tif_rawcp;
	103	if (!TIFFFlushData1(tif))
	104	return (-1);
	105	op = tif->tif_rawcp;
	106	while (slop-- > 0)
	107	op++ = lastliteral++;
	108	lastliteral = tif->tif_rawcp;
	109	} else {
	110	tif->tif_rawcc += op - tif->tif_rawcp;
	111	if (!TIFFFlushData1(tif))
	112	return (-1);
	113	op = tif->tif_rawcp;
	114	}
	115	}
	116	switch (state) {
	117	case BASE: /* initial state, set run/literal */
	118	if (n > 1) {
	119	state = RUN;
	120	if (n > 128) {
	121	*op++ = (tidata) -127;
	122	*op++ = (tidataval_t) b;
	123	n -= 128;
	124	goto again;
	125	}
	126	*op++ = (tidataval_t)(-(n-1));
	127	*op++ = (tidataval_t) b;
	128	} else {
	129	lastliteral = op;
	130	*op++ = 0;
	131	*op++ = (tidataval_t) b;
	132	state = LITERAL;
	133	}
	134	break;
	135	case LITERAL: /* last object was literal string */
	136	if (n > 1) {
	137	state = LITERAL_RUN;
	138	if (n > 128) {
	139	*op++ = (tidata) -127;
	140	*op++ = (tidataval_t) b;
	141	n -= 128;
	142	goto again;
	143	}
	144	op++ = (tidataval_t)(-(n-1)); / encode run */
	145	*op++ = (tidataval_t) b;
	146	} else { /* extend literal */
	147	if (++(*lastliteral) == 127)
	148	state = BASE;
	149	*op++ = (tidataval_t) b;
	150	}
	151	break;
	152	case RUN: /* last object was run */
	153	if (n > 1) {
	154	if (n > 128) {
	155	*op++ = (tidata) -127;
	156	*op++ = (tidataval_t) b;
	157	n -= 128;
	158	goto again;
	159	}
	160	*op++ = (tidataval_t)(-(n-1));
	161	*op++ = (tidataval_t) b;
	162	} else {
	163	lastliteral = op;
	164	*op++ = 0;
	165	*op++ = (tidataval_t) b;
	166	state = LITERAL;
	167	}
	168	break;
	169	case LITERAL_RUN: /* literal followed by a run */
	170	/*
	171	* Check to see if previous run should
	172	* be converted to a literal, in which
	173	* case we convert literal-run-literal
	174	* to a single literal.
	175	*/
	176	if (n == 1 && op[-2] == (tidata) -1 &&
	177	*lastliteral < 126) {
	178	state = (((*lastliteral) += 2) == 127 ?
	179	BASE : LITERAL);
	180	op[-2] = op[-1]; /* replicate */
	181	} else
	182	state = RUN;
	183	goto again;
	184	}
	185	}
	186	tif->tif_rawcc += op - tif->tif_rawcp;
	187	tif->tif_rawcp = op;
	188	return (1);
	189	}
	190
	191	/*
	192	* Encode a rectangular chunk of pixels. We break it up
	193	* into row-sized pieces to insure that encoded runs do
	194	* not span rows. Otherwise, there can be problems with
	195	* the decoder if data is read, for example, by scanlines
	196	* when it was encoded by strips.
	197	*/
	198	static int
	199	PackBitsEncodeChunk(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)
	200	{
	201	tsize_t rowsize = (tsize_t)tif->tif_data;
	202
	203	while ((long)cc > 0) {
	204	int chunk = rowsize;
	205
	206	if( cc < chunk )
	207	chunk = cc;
	208
	209	if (PackBitsEncode(tif, bp, chunk, s) < 0)
	210	return (-1);
	211	bp += chunk;
	212	cc -= chunk;
	213	}
	214	return (1);
	215	}
	216
	217	static int
	218	PackBitsDecode(TIFF* tif, tidata_t op, tsize_t occ, tsample_t s)
	219	{
	220	char *bp;
	221	tsize_t cc;
	222	long n;
	223	int b;
	224
	225	(void) s;
	226	bp = (char*) tif->tif_rawcp;
	227	cc = tif->tif_rawcc;
	228	while (cc > 0 && (long)occ > 0) {
	229	n = (long) *bp++, cc--;
	230	/*
	231	* Watch out for compilers that
	232	* don't sign extend chars...
	233	*/
	234	if (n >= 128)
	235	n -= 256;
	236	if (n < 0) { /* replicate next byte -n+1 times */
	237	if (n == -128) /* nop */
	238	continue;
	239	n = -n + 1;
	240	if( occ < n )
	241	{
	242	TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
	243	"PackBitsDecode: discarding %d bytes "
	244	"to avoid buffer overrun",
	245	n - occ);
	246	n = occ;
	247	}
	248	occ -= n;
	249	b = *bp++, cc--;
	250	while (n-- > 0)
	251	*op++ = (tidataval_t) b;
	252	} else { /* copy next n+1 bytes literally */
	253	if (occ < n + 1)
	254	{
	255	TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
	256	"PackBitsDecode: discarding %d bytes "
	257	"to avoid buffer overrun",
	258	n - occ + 1);
	259	n = occ - 1;
	260	}
	261	_TIFFmemcpy(op, bp, ++n);
	262	op += n; occ -= n;
	263	bp += n; cc -= n;
	264	}
	265	}
	266	tif->tif_rawcp = (tidata_t) bp;
	267	tif->tif_rawcc = cc;
	268	if (occ > 0) {
	269	TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
	270	"PackBitsDecode: Not enough data for scanline %ld",
	271	(long) tif->tif_row);
	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;
	285	tif->tif_postencode = PackBitsPostEncode;
	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: */