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