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