1 /* $Id: tif_next.c,v 1.16 2014-12-29 12:09:11 erouault 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 NEXT_SUPPORT
29 /*
30 * TIFF Library.
31 *
32 * NeXT 2-bit Grey Scale Compression Algorithm Support
33 */
34
35 #define SETPIXEL(op, v) { \
36 switch (npixels++ & 3) { \
37 case 0: op[0] = (unsigned char) ((v) << 6); break; \
38 case 1: op[0] |= (v) << 4; break; \
39 case 2: op[0] |= (v) << 2; break; \
40 case 3: *op++ |= (v); op_offset++; break; \
41 } \
42 }
43
44 #define LITERALROW 0x00
45 #define LITERALSPAN 0x40
46 #define WHITE ((1<<2)-1)
47
48 static int
NeXTDecode(TIFF * tif,uint8 * buf,tmsize_t occ,uint16 s)49 NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
50 {
51 static const char module[] = "NeXTDecode";
52 unsigned char *bp, *op;
53 tmsize_t cc;
54 uint8* row;
55 tmsize_t scanline, n;
56
57 (void) s;
58 /*
59 * Each scanline is assumed to start off as all
60 * white (we assume a PhotometricInterpretation
61 * of ``min-is-black'').
62 */
63 for (op = (unsigned char*) buf, cc = occ; cc-- > 0;)
64 *op++ = 0xff;
65
66 bp = (unsigned char *)tif->tif_rawcp;
67 cc = tif->tif_rawcc;
68 scanline = tif->tif_scanlinesize;
69 if (occ % scanline)
70 {
71 TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read");
72 return (0);
73 }
74 for (row = buf; cc > 0 && occ > 0; occ -= scanline, row += scanline) {
75 n = *bp++, cc--;
76 switch (n) {
77 case LITERALROW:
78 /*
79 * The entire scanline is given as literal values.
80 */
81 if (cc < scanline)
82 goto bad;
83 _TIFFmemcpy(row, bp, scanline);
84 bp += scanline;
85 cc -= scanline;
86 break;
87 case LITERALSPAN: {
88 tmsize_t off;
89 /*
90 * The scanline has a literal span that begins at some
91 * offset.
92 */
93 if( cc < 4 )
94 goto bad;
95 off = (bp[0] * 256) + bp[1];
96 n = (bp[2] * 256) + bp[3];
97 if (cc < 4+n || off+n > scanline)
98 goto bad;
99 _TIFFmemcpy(row+off, bp+4, n);
100 bp += 4+n;
101 cc -= 4+n;
102 break;
103 }
104 default: {
105 uint32 npixels = 0, grey;
106 uint32 imagewidth = tif->tif_dir.td_imagewidth;
107 if( isTiled(tif) )
108 imagewidth = tif->tif_dir.td_tilewidth;
109 tmsize_t op_offset = 0;
110
111 /*
112 * The scanline is composed of a sequence of constant
113 * color ``runs''. We shift into ``run mode'' and
114 * interpret bytes as codes of the form
115 * <color><npixels> until we've filled the scanline.
116 */
117 op = row;
118 for (;;) {
119 grey = (uint32)((n>>6) & 0x3);
120 n &= 0x3f;
121 /*
122 * Ensure the run does not exceed the scanline
123 * bounds, potentially resulting in a security
124 * issue.
125 */
126 while (n-- > 0 && npixels < imagewidth && op_offset < scanline)
127 SETPIXEL(op, grey);
128 if (npixels >= imagewidth)
129 break;
130 if (op_offset >= scanline ) {
131 TIFFErrorExt(tif->tif_clientdata, module, "Invalid data for scanline %ld",
132 (long) tif->tif_row);
133 return (0);
134 }
135 if (cc == 0)
136 goto bad;
137 n = *bp++, cc--;
138 }
139 break;
140 }
141 }
142 }
143 tif->tif_rawcp = (uint8*) bp;
144 tif->tif_rawcc = cc;
145 return (1);
146 bad:
147 TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld",
148 (long) tif->tif_row);
149 return (0);
150 }
151
152 static int
NeXTPreDecode(TIFF * tif,uint16 s)153 NeXTPreDecode(TIFF* tif, uint16 s)
154 {
155 static const char module[] = "NeXTPreDecode";
156 TIFFDirectory *td = &tif->tif_dir;
157 (void)s;
158
159 if( td->td_bitspersample != 2 )
160 {
161 TIFFErrorExt(tif->tif_clientdata, module, "Unsupported BitsPerSample = %d",
162 td->td_bitspersample);
163 return (0);
164 }
165 return (1);
166 }
167
168 int
TIFFInitNeXT(TIFF * tif,int scheme)169 TIFFInitNeXT(TIFF* tif, int scheme)
170 {
171 (void) scheme;
172 tif->tif_predecode = NeXTPreDecode;
173 tif->tif_decoderow = NeXTDecode;
174 tif->tif_decodestrip = NeXTDecode;
175 tif->tif_decodetile = NeXTDecode;
176 return (1);
177 }
178 #endif /* NEXT_SUPPORT */
179
180 /* vim: set ts=8 sts=8 sw=8 noet: */
181 /*
182 * Local Variables:
183 * mode: c
184 * c-basic-offset: 8
185 * fill-column: 78
186 * End:
187 */
188