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 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] |= (unsigned char)((v) << 4); \
42 : break; \
43 : case 2: \
44 : op[0] |= (unsigned char)((v) << 2); \
45 : break; \
46 : case 3: \
47 : *op++ |= (unsigned char)(v); \
48 : op_offset++; \
49 : break; \
50 : default: \
51 : break; \
52 : } \
53 : }
54 :
55 : #define LITERALROW 0x00
56 : #define LITERALSPAN 0x40
57 :
58 3 : static int NeXTDecode(TIFF *tif, uint8_t *buf, tmsize_t occ, uint16_t s)
59 : {
60 : static const char module[] = "NeXTDecode";
61 : unsigned char *bp, *op;
62 : tmsize_t cc;
63 : uint8_t *row;
64 : tmsize_t scanline, n;
65 :
66 : (void)s;
67 : /*
68 : * Each scanline is assumed to start off as all
69 : * white (we assume a PhotometricInterpretation
70 : * of ``min-is-black'').
71 : */
72 6 : for (op = (unsigned char *)buf, cc = occ; cc-- > 0;)
73 3 : *op++ = 0xff;
74 :
75 3 : bp = (unsigned char *)tif->tif_rawcp;
76 3 : cc = tif->tif_rawcc;
77 3 : scanline = tif->tif_dir.td_scanlinesize;
78 3 : if (occ % scanline)
79 : {
80 0 : TIFFErrorExtR(tif, module, "Fractional scanlines cannot be read");
81 0 : return (0);
82 : }
83 6 : for (row = buf; cc > 0 && occ > 0; occ -= scanline, row += scanline)
84 : {
85 3 : n = *bp++;
86 3 : cc--;
87 3 : switch (n)
88 : {
89 1 : case LITERALROW:
90 : /*
91 : * The entire scanline is given as literal values.
92 : */
93 1 : if (cc < scanline)
94 0 : goto bad;
95 1 : _TIFFmemcpy(row, bp, scanline);
96 1 : bp += scanline;
97 1 : cc -= scanline;
98 1 : break;
99 1 : case LITERALSPAN:
100 : {
101 : tmsize_t off;
102 : /*
103 : * The scanline has a literal span that begins at some
104 : * offset.
105 : */
106 1 : if (cc < 4)
107 0 : goto bad;
108 1 : off = (bp[0] * 256) + bp[1];
109 1 : n = (bp[2] * 256) + bp[3];
110 1 : if (cc < 4 + n || off + n > scanline)
111 0 : goto bad;
112 1 : _TIFFmemcpy(row + off, bp + 4, n);
113 1 : bp += 4 + n;
114 1 : cc -= 4 + n;
115 1 : break;
116 : }
117 1 : default:
118 : {
119 1 : uint32_t npixels = 0, grey;
120 1 : tmsize_t op_offset = 0;
121 1 : uint32_t imagewidth = tif->tif_dir.td_imagewidth;
122 1 : if (isTiled(tif))
123 0 : imagewidth = tif->tif_dir.td_tilewidth;
124 :
125 : /*
126 : * The scanline is composed of a sequence of constant
127 : * color ``runs''. We shift into ``run mode'' and
128 : * interpret bytes as codes of the form
129 : * <color><npixels> until we've filled the scanline.
130 : */
131 1 : op = row;
132 : for (;;)
133 : {
134 1 : grey = (uint32_t)((n >> 6) & 0x3);
135 1 : n &= 0x3f;
136 : /*
137 : * Ensure the run does not exceed the scanline
138 : * bounds, potentially resulting in a security
139 : * issue.
140 : */
141 5 : while (n-- > 0 && npixels < imagewidth &&
142 : op_offset < scanline)
143 4 : SETPIXEL(op, grey);
144 1 : if (npixels >= imagewidth)
145 1 : break;
146 0 : if (op_offset >= scanline)
147 : {
148 0 : TIFFErrorExtR(tif, module,
149 : "Invalid data for scanline %" PRIu32,
150 : tif->tif_dir.td_row);
151 0 : return (0);
152 : }
153 0 : if (cc == 0)
154 0 : goto bad;
155 0 : n = *bp++;
156 0 : cc--;
157 : }
158 1 : break;
159 : }
160 : }
161 : }
162 3 : tif->tif_rawcp = (uint8_t *)bp;
163 3 : tif->tif_rawcc = cc;
164 3 : return (1);
165 0 : bad:
166 0 : TIFFErrorExtR(tif, module, "Not enough data for scanline %" PRIu32,
167 : tif->tif_dir.td_row);
168 0 : return (0);
169 : }
170 :
171 3 : static int NeXTPreDecode(TIFF *tif, uint16_t s)
172 : {
173 : static const char module[] = "NeXTPreDecode";
174 3 : TIFFDirectory *td = &tif->tif_dir;
175 : (void)s;
176 :
177 3 : if (td->td_bitspersample != 2)
178 : {
179 0 : TIFFErrorExtR(tif, module, "Unsupported BitsPerSample = %" PRIu16,
180 0 : td->td_bitspersample);
181 0 : return (0);
182 : }
183 3 : return (1);
184 : }
185 :
186 6 : int TIFFInitNeXT(TIFF *tif, int scheme)
187 : {
188 : (void)scheme;
189 6 : tif->tif_predecode = NeXTPreDecode;
190 6 : tif->tif_decoderow = NeXTDecode;
191 6 : tif->tif_decodestrip = NeXTDecode;
192 6 : tif->tif_decodetile = NeXTDecode;
193 6 : return (1);
194 : }
195 : #endif /* NEXT_SUPPORT */
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