source: liacs/MIR2010/SourceCode/cximage/tiff/tif_packbits.c@ 137

Last change on this file since 137 was 95, checked in by Rick van der Zwet, 15 years ago

Bad boy, improper move of directory
File size: 7.6 KB
RevLine 
[95]1/* $Id: tif_packbits.c,v 1.13 2006/02/07 11:03:29 dron Exp $ */
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
36static int
37PackBitsPreEncode(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
53static int
54PackBitsPostEncode(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 */
66typedef unsigned char tidata;
67
68/*
69 * Encode a run of pixels.
70 */
71static int
72PackBitsEncode(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 */
198static int
199PackBitsEncodeChunk(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
217static int
218PackBitsDecode(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
277int
278TIFFInitPackBits(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: */
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