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 NEXT_SUPPORT
27 /*
28 * TIFF Library.
29 *
30 * NeXT 2-bit Grey Scale Compression Algorithm Support
31 */
32
33 #define SETPIXEL(op, v) \
34 { \
35 switch (npixels++ & 3) \
36 { \
37 case 0: \
38 op[0] = (unsigned char)((v) << 6); \
39 break; \
40 case 1: \
41 op[0] |= (v) << 4; \
42 break; \
43 case 2: \
44 op[0] |= (v) << 2; \
45 break; \
46 case 3: \
47 *op++ |= (v); \
48 op_offset++; \
49 break; \
50 } \
51 }
52
53 #define LITERALROW 0x00
54 #define LITERALSPAN 0x40
55 #define WHITE ((1 << 2) - 1)
56
NeXTDecode(TIFF * tif,uint8_t * buf,tmsize_t occ,uint16_t s)57 static int NeXTDecode(TIFF *tif, uint8_t *buf, tmsize_t occ, uint16_t s)
58 {
59 static const char module[] = "NeXTDecode";
60 unsigned char *bp, *op;
61 tmsize_t cc;
62 uint8_t *row;
63 tmsize_t scanline, n;
64
65 (void)s;
66 /*
67 * Each scanline is assumed to start off as all
68 * white (we assume a PhotometricInterpretation
69 * of ``min-is-black'').
70 */
71 for (op = (unsigned char *)buf, cc = occ; cc-- > 0;)
72 *op++ = 0xff;
73
74 bp = (unsigned char *)tif->tif_rawcp;
75 cc = tif->tif_rawcc;
76 scanline = tif->tif_scanlinesize;
77 if (occ % scanline)
78 {
79 TIFFErrorExtR(tif, module, "Fractional scanlines cannot be read");
80 return (0);
81 }
82 for (row = buf; cc > 0 && occ > 0; occ -= scanline, row += scanline)
83 {
84 n = *bp++;
85 cc--;
86 switch (n)
87 {
88 case LITERALROW:
89 /*
90 * The entire scanline is given as literal values.
91 */
92 if (cc < scanline)
93 goto bad;
94 _TIFFmemcpy(row, bp, scanline);
95 bp += scanline;
96 cc -= scanline;
97 break;
98 case LITERALSPAN:
99 {
100 tmsize_t off;
101 /*
102 * The scanline has a literal span that begins at some
103 * offset.
104 */
105 if (cc < 4)
106 goto bad;
107 off = (bp[0] * 256) + bp[1];
108 n = (bp[2] * 256) + bp[3];
109 if (cc < 4 + n || off + n > scanline)
110 goto bad;
111 _TIFFmemcpy(row + off, bp + 4, n);
112 bp += 4 + n;
113 cc -= 4 + n;
114 break;
115 }
116 default:
117 {
118 uint32_t npixels = 0, grey;
119 tmsize_t op_offset = 0;
120 uint32_t imagewidth = tif->tif_dir.td_imagewidth;
121 if (isTiled(tif))
122 imagewidth = tif->tif_dir.td_tilewidth;
123
124 /*
125 * The scanline is composed of a sequence of constant
126 * color ``runs''. We shift into ``run mode'' and
127 * interpret bytes as codes of the form
128 * <color><npixels> until we've filled the scanline.
129 */
130 op = row;
131 for (;;)
132 {
133 grey = (uint32_t)((n >> 6) & 0x3);
134 n &= 0x3f;
135 /*
136 * Ensure the run does not exceed the scanline
137 * bounds, potentially resulting in a security
138 * issue.
139 */
140 while (n-- > 0 && npixels < imagewidth &&
141 op_offset < scanline)
142 SETPIXEL(op, grey);
143 if (npixels >= imagewidth)
144 break;
145 if (op_offset >= scanline)
146 {
147 TIFFErrorExtR(tif, module,
148 "Invalid data for scanline %" PRIu32,
149 tif->tif_row);
150 return (0);
151 }
152 if (cc == 0)
153 goto bad;
154 n = *bp++;
155 cc--;
156 }
157 break;
158 }
159 }
160 }
161 tif->tif_rawcp = (uint8_t *)bp;
162 tif->tif_rawcc = cc;
163 return (1);
164 bad:
165 TIFFErrorExtR(tif, module, "Not enough data for scanline %" PRIu32,
166 tif->tif_row);
167 return (0);
168 }
169
NeXTPreDecode(TIFF * tif,uint16_t s)170 static int NeXTPreDecode(TIFF *tif, uint16_t s)
171 {
172 static const char module[] = "NeXTPreDecode";
173 TIFFDirectory *td = &tif->tif_dir;
174 (void)s;
175
176 if (td->td_bitspersample != 2)
177 {
178 TIFFErrorExtR(tif, module, "Unsupported BitsPerSample = %" PRIu16,
179 td->td_bitspersample);
180 return (0);
181 }
182 return (1);
183 }
184
TIFFInitNeXT(TIFF * tif,int scheme)185 int TIFFInitNeXT(TIFF *tif, int scheme)
186 {
187 (void)scheme;
188 tif->tif_predecode = NeXTPreDecode;
189 tif->tif_decoderow = NeXTDecode;
190 tif->tif_decodestrip = NeXTDecode;
191 tif->tif_decodetile = NeXTDecode;
192 return (1);
193 }
194 #endif /* NEXT_SUPPORT */
195