Line data Source code
1 : /*
2 : * Copyright (c) 1988-1997 Sam Leffler
3 : * Copyright (c) 1991-1997 Silicon Graphics, Inc.
4 : *
5 : * Permission to use, copy, modify, distribute, and sell this software and
6 : * its documentation for any purpose is hereby granted without fee, provided
7 : * that (i) the above copyright notices and this permission notice appear in
8 : * all copies of the software and related documentation, and (ii) the names of
9 : * Sam Leffler and Silicon Graphics may not be used in any advertising or
10 : * publicity relating to the software without the specific, prior written
11 : * permission of Sam Leffler and Silicon Graphics.
12 : *
13 : * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
14 : * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
15 : * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
16 : *
17 : * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
18 : * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 : * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
20 : * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
21 : * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 : * OF THIS SOFTWARE.
23 : */
24 :
25 : #include "tiffiop.h"
26 : #ifdef PACKBITS_SUPPORT
27 : /*
28 : * TIFF Library.
29 : *
30 : * PackBits Compression Algorithm Support
31 : */
32 : #include <stdio.h>
33 :
34 : #ifndef PACKBITS_READ_ONLY
35 :
36 15 : static int PackBitsPreEncode(TIFF *tif, uint16_t s)
37 : {
38 : (void)s;
39 :
40 15 : tif->tif_data = (uint8_t *)_TIFFmallocExt(tif, sizeof(tmsize_t));
41 15 : if (tif->tif_data == NULL)
42 0 : return (0);
43 : /*
44 : * Calculate the scanline/tile-width size in bytes.
45 : */
46 15 : if (isTiled(tif))
47 7 : *(tmsize_t *)tif->tif_data = TIFFTileRowSize(tif);
48 : else
49 8 : *(tmsize_t *)tif->tif_data = TIFFScanlineSize(tif);
50 15 : return (1);
51 : }
52 :
53 15 : static int PackBitsPostEncode(TIFF *tif)
54 : {
55 15 : if (tif->tif_data)
56 15 : _TIFFfreeExt(tif, tif->tif_data);
57 15 : return (1);
58 : }
59 :
60 : /*
61 : * Encode a run of pixels.
62 : */
63 4708 : static int PackBitsEncode(TIFF *tif, uint8_t *buf, tmsize_t cc, uint16_t s)
64 : {
65 4708 : unsigned char *bp = (unsigned char *)buf;
66 : uint8_t *op;
67 : uint8_t *ep;
68 : uint8_t *lastliteral;
69 : long n, slop;
70 : int b;
71 : enum
72 : {
73 : BASE,
74 : LITERAL,
75 : RUN,
76 : LITERAL_RUN
77 : } state;
78 :
79 : (void)s;
80 4708 : op = tif->tif_rawcp;
81 4708 : ep = tif->tif_rawdata + tif->tif_rawdatasize;
82 4708 : state = BASE;
83 4708 : lastliteral = NULL;
84 76452 : while (cc > 0)
85 : {
86 : /*
87 : * Find the longest string of identical bytes.
88 : */
89 71744 : b = *bp++;
90 71744 : cc--;
91 71744 : n = 1;
92 118024 : for (; cc > 0 && b == *bp; cc--, bp++)
93 46280 : n++;
94 71744 : again:
95 72108 : if (op + 2 >= ep)
96 : { /* insure space for new data */
97 : /*
98 : * Be careful about writing the last
99 : * literal. Must write up to that point
100 : * and then copy the remainder to the
101 : * front of the buffer.
102 : */
103 0 : if (state == LITERAL || state == LITERAL_RUN)
104 : {
105 0 : slop = (long)(op - lastliteral);
106 0 : tif->tif_rawcc += (tmsize_t)(lastliteral - tif->tif_rawcp);
107 0 : if (!TIFFFlushData1(tif))
108 0 : return (0);
109 0 : op = tif->tif_rawcp;
110 0 : while (slop-- > 0)
111 0 : *op++ = *lastliteral++;
112 0 : lastliteral = tif->tif_rawcp;
113 : }
114 : else
115 : {
116 0 : tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
117 0 : if (!TIFFFlushData1(tif))
118 0 : return (0);
119 0 : op = tif->tif_rawcp;
120 : }
121 : }
122 72108 : switch (state)
123 : {
124 5172 : case BASE: /* initial state, set run/literal */
125 5172 : if (n > 1)
126 : {
127 4280 : state = RUN;
128 4280 : if (n > 128)
129 : {
130 118 : *op++ = (uint8_t)-127;
131 118 : *op++ = (uint8_t)b;
132 118 : n -= 128;
133 118 : goto again;
134 : }
135 4162 : *op++ = (uint8_t)(-(n - 1));
136 4162 : *op++ = (uint8_t)b;
137 : }
138 : else
139 : {
140 892 : lastliteral = op;
141 892 : *op++ = 0;
142 892 : *op++ = (uint8_t)b;
143 892 : state = LITERAL;
144 : }
145 5054 : break;
146 66816 : case LITERAL: /* last object was literal string */
147 66816 : if (n > 1)
148 : {
149 0 : state = LITERAL_RUN;
150 0 : if (n > 128)
151 : {
152 0 : *op++ = (uint8_t)-127;
153 0 : *op++ = (uint8_t)b;
154 0 : n -= 128;
155 0 : goto again;
156 : }
157 0 : *op++ = (uint8_t)(-(n - 1)); /* encode run */
158 0 : *op++ = (uint8_t)b;
159 : }
160 : else
161 : { /* extend literal */
162 66816 : if (++(*lastliteral) == 127)
163 464 : state = BASE;
164 66816 : *op++ = (uint8_t)b;
165 : }
166 66816 : break;
167 120 : case RUN: /* last object was run */
168 120 : if (n > 1)
169 : {
170 118 : if (n > 128)
171 : {
172 246 : *op++ = (uint8_t)-127;
173 246 : *op++ = (uint8_t)b;
174 246 : n -= 128;
175 246 : goto again;
176 : }
177 0 : *op++ = (uint8_t)(-(n - 1));
178 0 : *op++ = (uint8_t)b;
179 : }
180 : else
181 : {
182 2 : lastliteral = op;
183 2 : *op++ = 0;
184 2 : *op++ = (uint8_t)b;
185 2 : state = LITERAL;
186 : }
187 0 : break;
188 0 : case LITERAL_RUN: /* literal followed by a run */
189 : /*
190 : * Check to see if previous run should
191 : * be converted to a literal, in which
192 : * case we convert literal-run-literal
193 : * to a single literal.
194 : */
195 0 : if (n == 1 && op[-2] == (uint8_t)-1 && *lastliteral < 126)
196 : {
197 0 : state = (((*lastliteral) += 2) == 127 ? BASE : LITERAL);
198 0 : op[-2] = op[-1]; /* replicate */
199 : }
200 : else
201 0 : state = RUN;
202 0 : goto again;
203 0 : default:
204 0 : break;
205 : }
206 : }
207 4708 : tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
208 4708 : tif->tif_rawcp = op;
209 4708 : return (1);
210 : }
211 :
212 : /*
213 : * Encode a rectangular chunk of pixels. We break it up
214 : * into row-sized pieces to insure that encoded runs do
215 : * not span rows. Otherwise, there can be problems with
216 : * the decoder if data is read, for example, by scanlines
217 : * when it was encoded by strips.
218 : */
219 15 : static int PackBitsEncodeChunk(TIFF *tif, uint8_t *bp, tmsize_t cc, uint16_t s)
220 : {
221 15 : tmsize_t rowsize = *(tmsize_t *)tif->tif_data;
222 :
223 4723 : while (cc > 0)
224 : {
225 4708 : tmsize_t chunk = rowsize;
226 :
227 4708 : if (cc < chunk)
228 0 : chunk = cc;
229 :
230 4708 : if (PackBitsEncode(tif, bp, chunk, s) < 0)
231 0 : return (-1);
232 4708 : bp += chunk;
233 4708 : cc -= chunk;
234 : }
235 15 : return (1);
236 : }
237 :
238 : #endif
239 :
240 413 : static int PackBitsDecode(TIFF *tif, uint8_t *op, tmsize_t occ, uint16_t s)
241 : {
242 : static const char module[] = "PackBitsDecode";
243 : int8_t *bp;
244 : tmsize_t cc;
245 : long n;
246 : int b;
247 :
248 : (void)s;
249 413 : bp = (int8_t *)tif->tif_rawcp;
250 413 : cc = tif->tif_rawcc;
251 29259 : while (cc > 0 && occ > 0)
252 : {
253 28850 : n = (long)*bp++;
254 28850 : cc--;
255 28850 : if (n < 0)
256 : { /* replicate next byte -n+1 times */
257 23842 : if (n == -128) /* nop */
258 6 : continue;
259 23836 : n = -n + 1;
260 23836 : if (occ < (tmsize_t)n)
261 : {
262 122 : TIFFWarningExtR(tif, module,
263 : "Discarding %" TIFF_SSIZE_FORMAT
264 : " bytes to avoid buffer overrun",
265 : (tmsize_t)n - occ);
266 122 : n = (long)occ;
267 : }
268 23836 : if (cc == 0)
269 : {
270 1 : TIFFWarningExtR(
271 : tif, module,
272 : "Terminating PackBitsDecode due to lack of data.");
273 1 : break;
274 : }
275 23835 : occ -= n;
276 23835 : b = *bp++;
277 23835 : cc--;
278 1483095 : while (n-- > 0)
279 1459260 : *op++ = (uint8_t)b;
280 : }
281 : else
282 : { /* copy next n+1 bytes literally */
283 5008 : if (occ < (tmsize_t)(n + 1))
284 : {
285 88 : TIFFWarningExtR(tif, module,
286 : "Discarding %" TIFF_SSIZE_FORMAT
287 : " bytes to avoid buffer overrun",
288 88 : (tmsize_t)n - occ + 1);
289 88 : n = (long)occ - 1;
290 : }
291 5008 : if (cc < (tmsize_t)(n + 1))
292 : {
293 3 : TIFFWarningExtR(
294 : tif, module,
295 : "Terminating PackBitsDecode due to lack of data.");
296 3 : break;
297 : }
298 5005 : _TIFFmemcpy(op, bp, ++n);
299 5005 : op += n;
300 5005 : occ -= n;
301 5005 : bp += n;
302 5005 : cc -= n;
303 : }
304 : }
305 413 : tif->tif_rawcp = (uint8_t *)bp;
306 413 : tif->tif_rawcc = cc;
307 413 : if (occ > 0)
308 : {
309 6 : memset(op, 0, (size_t)occ);
310 6 : TIFFErrorExtR(tif, module, "Not enough data for scanline %" PRIu32,
311 : tif->tif_row);
312 6 : return (0);
313 : }
314 407 : return (1);
315 : }
316 :
317 113 : int TIFFInitPackBits(TIFF *tif, int scheme)
318 : {
319 : (void)scheme;
320 113 : tif->tif_decoderow = PackBitsDecode;
321 113 : tif->tif_decodestrip = PackBitsDecode;
322 113 : tif->tif_decodetile = PackBitsDecode;
323 : #ifndef PACKBITS_READ_ONLY
324 106 : tif->tif_preencode = PackBitsPreEncode;
325 106 : tif->tif_postencode = PackBitsPostEncode;
326 106 : tif->tif_encoderow = PackBitsEncode;
327 106 : tif->tif_encodestrip = PackBitsEncodeChunk;
328 106 : tif->tif_encodetile = PackBitsEncodeChunk;
329 : #endif
330 113 : return (1);
331 : }
332 : #endif /* PACKBITS_SUPPORT */
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