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 15 : static int PackBitsPreEncode(TIFF *tif, uint16_t s)
35 : {
36 : (void)s;
37 :
38 15 : tif->tif_data = (uint8_t *)_TIFFmallocExt(tif, sizeof(tmsize_t));
39 15 : if (tif->tif_data == NULL)
40 0 : return (0);
41 : /*
42 : * Calculate the scanline/tile-width size in bytes.
43 : */
44 15 : if (isTiled(tif))
45 7 : *(tmsize_t *)tif->tif_data = TIFFTileRowSize(tif);
46 : else
47 8 : *(tmsize_t *)tif->tif_data = TIFFScanlineSize(tif);
48 15 : return (1);
49 : }
50 :
51 15 : static int PackBitsPostEncode(TIFF *tif)
52 : {
53 15 : if (tif->tif_data)
54 15 : _TIFFfreeExt(tif, tif->tif_data);
55 15 : return (1);
56 : }
57 :
58 : /*
59 : * Encode a run of pixels.
60 : */
61 4708 : static int PackBitsEncode(TIFF *tif, uint8_t *buf, tmsize_t cc, uint16_t s)
62 : {
63 4708 : unsigned char *bp = (unsigned char *)buf;
64 : uint8_t *op;
65 : uint8_t *ep;
66 : uint8_t *lastliteral;
67 : long n, slop;
68 : int b;
69 : enum
70 : {
71 : BASE,
72 : LITERAL,
73 : RUN,
74 : LITERAL_RUN
75 : } state;
76 :
77 : (void)s;
78 4708 : op = tif->tif_rawcp;
79 4708 : ep = tif->tif_rawdata + tif->tif_rawdatasize;
80 4708 : state = BASE;
81 4708 : lastliteral = 0;
82 4708 : while (cc > 0)
83 : {
84 : /*
85 : * Find the longest string of identical bytes.
86 : */
87 74472 : b = *bp++;
88 74472 : cc--;
89 74472 : n = 1;
90 120752 : for (; cc > 0 && b == *bp; cc--, bp++)
91 46280 : n++;
92 74472 : again:
93 74590 : if (op + 2 >= ep)
94 : { /* insure space for new data */
95 : /*
96 : * Be careful about writing the last
97 : * literal. Must write up to that point
98 : * and then copy the remainder to the
99 : * front of the buffer.
100 : */
101 0 : if (state == LITERAL || state == LITERAL_RUN)
102 : {
103 0 : slop = (long)(op - lastliteral);
104 0 : tif->tif_rawcc += (tmsize_t)(lastliteral - tif->tif_rawcp);
105 0 : if (!TIFFFlushData1(tif))
106 0 : return (0);
107 0 : op = tif->tif_rawcp;
108 0 : while (slop-- > 0)
109 0 : *op++ = *lastliteral++;
110 0 : lastliteral = tif->tif_rawcp;
111 : }
112 : else
113 : {
114 0 : tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
115 0 : if (!TIFFFlushData1(tif))
116 0 : return (0);
117 0 : op = tif->tif_rawcp;
118 : }
119 : }
120 74590 : switch (state)
121 : {
122 5172 : case BASE: /* initial state, set run/literal */
123 5172 : if (n > 1)
124 : {
125 4280 : state = RUN;
126 4280 : if (n > 128)
127 : {
128 118 : *op++ = (uint8_t)-127;
129 118 : *op++ = (uint8_t)b;
130 118 : n -= 128;
131 118 : goto again;
132 : }
133 4162 : *op++ = (uint8_t)(-(n - 1));
134 4162 : *op++ = (uint8_t)b;
135 : }
136 : else
137 : {
138 892 : lastliteral = op;
139 892 : *op++ = 0;
140 892 : *op++ = (uint8_t)b;
141 892 : state = LITERAL;
142 : }
143 5054 : break;
144 69298 : case LITERAL: /* last object was literal string */
145 69298 : if (n > 1)
146 : {
147 0 : state = LITERAL_RUN;
148 0 : if (n > 128)
149 : {
150 0 : *op++ = (uint8_t)-127;
151 0 : *op++ = (uint8_t)b;
152 0 : n -= 128;
153 0 : goto again;
154 : }
155 0 : *op++ = (uint8_t)(-(n - 1)); /* encode run */
156 0 : *op++ = (uint8_t)b;
157 : }
158 : else
159 : { /* extend literal */
160 69298 : if (++(*lastliteral) == 127)
161 464 : state = BASE;
162 69298 : *op++ = (uint8_t)b;
163 : }
164 69298 : break;
165 120 : case RUN: /* last object was run */
166 120 : if (n > 1)
167 : {
168 118 : if (n > 128)
169 : {
170 0 : *op++ = (uint8_t)-127;
171 0 : *op++ = (uint8_t)b;
172 0 : n -= 128;
173 0 : goto again;
174 : }
175 118 : *op++ = (uint8_t)(-(n - 1));
176 118 : *op++ = (uint8_t)b;
177 : }
178 : else
179 : {
180 2 : lastliteral = op;
181 2 : *op++ = 0;
182 2 : *op++ = (uint8_t)b;
183 2 : state = LITERAL;
184 : }
185 120 : break;
186 0 : case LITERAL_RUN: /* literal followed by a run */
187 : /*
188 : * Check to see if previous run should
189 : * be converted to a literal, in which
190 : * case we convert literal-run-literal
191 : * to a single literal.
192 : */
193 0 : if (n == 1 && op[-2] == (uint8_t)-1 && *lastliteral < 126)
194 : {
195 0 : state = (((*lastliteral) += 2) == 127 ? BASE : LITERAL);
196 0 : op[-2] = op[-1]; /* replicate */
197 : }
198 : else
199 0 : state = RUN;
200 0 : goto again;
201 : }
202 79180 : }
203 4708 : tif->tif_rawcc += (tmsize_t)(op - tif->tif_rawcp);
204 4708 : tif->tif_rawcp = op;
205 4708 : return (1);
206 : }
207 :
208 : /*
209 : * Encode a rectangular chunk of pixels. We break it up
210 : * into row-sized pieces to insure that encoded runs do
211 : * not span rows. Otherwise, there can be problems with
212 : * the decoder if data is read, for example, by scanlines
213 : * when it was encoded by strips.
214 : */
215 15 : static int PackBitsEncodeChunk(TIFF *tif, uint8_t *bp, tmsize_t cc, uint16_t s)
216 : {
217 15 : tmsize_t rowsize = *(tmsize_t *)tif->tif_data;
218 :
219 4723 : while (cc > 0)
220 : {
221 4708 : tmsize_t chunk = rowsize;
222 :
223 4708 : if (cc < chunk)
224 0 : chunk = cc;
225 :
226 4708 : if (PackBitsEncode(tif, bp, chunk, s) < 0)
227 0 : return (-1);
228 4708 : bp += chunk;
229 4708 : cc -= chunk;
230 : }
231 15 : return (1);
232 : }
233 :
234 402 : static int PackBitsDecode(TIFF *tif, uint8_t *op, tmsize_t occ, uint16_t s)
235 : {
236 : static const char module[] = "PackBitsDecode";
237 : int8_t *bp;
238 : tmsize_t cc;
239 : long n;
240 : int b;
241 :
242 : (void)s;
243 402 : bp = (int8_t *)tif->tif_rawcp;
244 402 : cc = tif->tif_rawcc;
245 20102 : while (cc > 0 && occ > 0)
246 : {
247 19703 : n = (long)*bp++;
248 19703 : cc--;
249 19703 : if (n < 0)
250 : { /* replicate next byte -n+1 times */
251 15178 : if (n == -128) /* nop */
252 6 : continue;
253 15172 : n = -n + 1;
254 15172 : if (occ < (tmsize_t)n)
255 : {
256 122 : TIFFWarningExtR(tif, module,
257 : "Discarding %" TIFF_SSIZE_FORMAT
258 : " bytes to avoid buffer overrun",
259 : (tmsize_t)n - occ);
260 122 : n = (long)occ;
261 : }
262 15172 : if (cc == 0)
263 : {
264 1 : TIFFWarningExtR(
265 : tif, module,
266 : "Terminating PackBitsDecode due to lack of data.");
267 1 : break;
268 : }
269 15171 : occ -= n;
270 15171 : b = *bp++;
271 15171 : cc--;
272 700124 : while (n-- > 0)
273 684953 : *op++ = (uint8_t)b;
274 : }
275 : else
276 : { /* copy next n+1 bytes literally */
277 4525 : if (occ < (tmsize_t)(n + 1))
278 : {
279 88 : TIFFWarningExtR(tif, module,
280 : "Discarding %" TIFF_SSIZE_FORMAT
281 : " bytes to avoid buffer overrun",
282 88 : (tmsize_t)n - occ + 1);
283 88 : n = (long)occ - 1;
284 : }
285 4525 : if (cc < (tmsize_t)(n + 1))
286 : {
287 2 : TIFFWarningExtR(
288 : tif, module,
289 : "Terminating PackBitsDecode due to lack of data.");
290 2 : break;
291 : }
292 4523 : _TIFFmemcpy(op, bp, ++n);
293 4523 : op += n;
294 4523 : occ -= n;
295 4523 : bp += n;
296 4523 : cc -= n;
297 : }
298 : }
299 402 : tif->tif_rawcp = (uint8_t *)bp;
300 402 : tif->tif_rawcc = cc;
301 402 : if (occ > 0)
302 : {
303 3 : TIFFErrorExtR(tif, module, "Not enough data for scanline %" PRIu32,
304 : tif->tif_row);
305 3 : return (0);
306 : }
307 399 : return (1);
308 : }
309 :
310 105 : int TIFFInitPackBits(TIFF *tif, int scheme)
311 : {
312 : (void)scheme;
313 105 : tif->tif_decoderow = PackBitsDecode;
314 105 : tif->tif_decodestrip = PackBitsDecode;
315 105 : tif->tif_decodetile = PackBitsDecode;
316 105 : tif->tif_preencode = PackBitsPreEncode;
317 105 : tif->tif_postencode = PackBitsPostEncode;
318 105 : tif->tif_encoderow = PackBitsEncode;
319 105 : tif->tif_encodestrip = PackBitsEncodeChunk;
320 105 : tif->tif_encodetile = PackBitsEncodeChunk;
321 105 : return (1);
322 : }
323 : #endif /* PACKBITS_SUPPORT */
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