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1/* $Header$ */
2
3/*
4 * Copyright (c) 1991-1997 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/*
28 * TIFF Library.
29 *
30 * Strip-organized Image Support Routines.
31 */
32#include "tiffiop.h"
33
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34static uint32
35summarize(TIFF* tif, size_t summand1, size_t summand2, const char* where)
36{
37 uint32 bytes = summand1 + summand2;
38
39 if (bytes - summand1 != summand2) {
40 TIFFError(tif->tif_name, "Integer overflow in %s", where);
41 bytes = 0;
42 }
43
44 return (bytes);
45}
46
47static uint32
48multiply(TIFF* tif, size_t nmemb, size_t elem_size, const char* where)
49{
50 uint32 bytes = nmemb * elem_size;
51
52 if (elem_size && bytes / elem_size != nmemb) {
53 TIFFError(tif->tif_name, "Integer overflow in %s", where);
54 bytes = 0;
55 }
56
57 return (bytes);
58}
59
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60/*
61 * Compute which strip a (row,sample) value is in.
62 */
63tstrip_t
64TIFFComputeStrip(TIFF* tif, uint32 row, tsample_t sample)
65{
66 TIFFDirectory *td = &tif->tif_dir;
67 tstrip_t strip;
68
69 strip = row / td->td_rowsperstrip;
70 if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
71 if (sample >= td->td_samplesperpixel) {
72 TIFFError(tif->tif_name,
73 "%u: Sample out of range, max %u",
74 sample, td->td_samplesperpixel);
75 return ((tstrip_t) 0);
76 }
77 strip += sample*td->td_stripsperimage;
78 }
79 return (strip);
80}
81
82/*
83 * Compute how many strips are in an image.
84 */
85tstrip_t
86TIFFNumberOfStrips(TIFF* tif)
87{
88 TIFFDirectory *td = &tif->tif_dir;
89 tstrip_t nstrips;
90
91 nstrips = (td->td_rowsperstrip == (uint32) -1 ?
92 (td->td_imagelength != 0 ? 1 : 0) :
93 TIFFhowmany(td->td_imagelength, td->td_rowsperstrip));
94 if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
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95 nstrips = multiply(tif, nstrips, td->td_samplesperpixel,
96 "TIFFNumberOfStrips");
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97 return (nstrips);
98}
99
100/*
101 * Compute the # bytes in a variable height, row-aligned strip.
102 */
103tsize_t
104TIFFVStripSize(TIFF* tif, uint32 nrows)
105{
106 TIFFDirectory *td = &tif->tif_dir;
107
108 if (nrows == (uint32) -1)
109 nrows = td->td_imagelength;
110#ifdef YCBCR_SUPPORT
111 if (td->td_planarconfig == PLANARCONFIG_CONTIG &&
112 td->td_photometric == PHOTOMETRIC_YCBCR &&
113 !isUpSampled(tif)) {
114 /*
115 * Packed YCbCr data contain one Cb+Cr for every
116 * HorizontalSampling*VerticalSampling Y values.
117 * Must also roundup width and height when calculating
118 * since images that are not a multiple of the
119 * horizontal/vertical subsampling area include
120 * YCbCr data for the extended image.
121 */
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122 uint16 ycbcrsubsampling[2];
123 tsize_t w, scanline, samplingarea;
124
125 TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING,
126 ycbcrsubsampling + 0,
127 ycbcrsubsampling + 1 );
128
129 w = TIFFroundup(td->td_imagewidth, ycbcrsubsampling[0]);
130 scanline = TIFFhowmany8(multiply(tif, w, td->td_bitspersample,
131 "TIFFVStripSize"));
132 samplingarea = ycbcrsubsampling[0]*ycbcrsubsampling[1];
133 nrows = TIFFroundup(nrows, ycbcrsubsampling[1]);
b47c832e 134 /* NB: don't need TIFFhowmany here 'cuz everything is rounded */
00cb87b4 135 scanline = multiply(tif, nrows, scanline, "TIFFVStripSize");
b47c832e 136 return ((tsize_t)
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137 summarize(tif, scanline,
138 multiply(tif, 2, scanline / samplingarea,
139 "TIFFVStripSize"), "TIFFVStripSize"));
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140 } else
141#endif
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142 return ((tsize_t) multiply(tif, nrows, TIFFScanlineSize(tif),
143 "TIFFVStripSize"));
144}
145
146
147/*
148 * Compute the # bytes in a raw strip.
149 */
150tsize_t
151TIFFRawStripSize(TIFF* tif, tstrip_t strip)
152{
153 TIFFDirectory* td = &tif->tif_dir;
154 tsize_t bytecount = td->td_stripbytecount[strip];
155
156 if (bytecount <= 0) {
157 TIFFError(tif->tif_name,
158 "%lu: Invalid strip byte count, strip %lu",
159 (u_long) bytecount, (u_long) strip);
160 bytecount = (tsize_t) -1;
161 }
162
163 return bytecount;
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164}
165
166/*
167 * Compute the # bytes in a (row-aligned) strip.
168 *
169 * Note that if RowsPerStrip is larger than the
170 * recorded ImageLength, then the strip size is
171 * truncated to reflect the actual space required
172 * to hold the strip.
173 */
174tsize_t
175TIFFStripSize(TIFF* tif)
176{
177 TIFFDirectory* td = &tif->tif_dir;
178 uint32 rps = td->td_rowsperstrip;
179 if (rps > td->td_imagelength)
180 rps = td->td_imagelength;
181 return (TIFFVStripSize(tif, rps));
182}
183
184/*
185 * Compute a default strip size based on the image
186 * characteristics and a requested value. If the
187 * request is <1 then we choose a strip size according
188 * to certain heuristics.
189 */
190uint32
191TIFFDefaultStripSize(TIFF* tif, uint32 request)
192{
193 return (*tif->tif_defstripsize)(tif, request);
194}
195
196uint32
197_TIFFDefaultStripSize(TIFF* tif, uint32 s)
198{
199 if ((int32) s < 1) {
200 /*
201 * If RowsPerStrip is unspecified, try to break the
202 * image up into strips that are approximately 8Kbytes.
203 */
204 tsize_t scanline = TIFFScanlineSize(tif);
205 s = (uint32)(8*1024) / (scanline == 0 ? 1 : scanline);
206 if (s == 0) /* very wide images */
207 s = 1;
208 }
209 return (s);
210}
211
212/*
213 * Return the number of bytes to read/write in a call to
214 * one of the scanline-oriented i/o routines. Note that
215 * this number may be 1/samples-per-pixel if data is
216 * stored as separate planes.
217 */
218tsize_t
219TIFFScanlineSize(TIFF* tif)
220{
221 TIFFDirectory *td = &tif->tif_dir;
222 tsize_t scanline;
223
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224 scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
225 "TIFFScanlineSize");
b47c832e 226 if (td->td_planarconfig == PLANARCONFIG_CONTIG)
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227 scanline = multiply (tif, scanline, td->td_samplesperpixel,
228 "TIFFScanlineSize");
229 return ((tsize_t) TIFFhowmany8(scanline));
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230}
231
232/*
233 * Return the number of bytes required to store a complete
234 * decoded and packed raster scanline (as opposed to the
235 * I/O size returned by TIFFScanlineSize which may be less
236 * if data is store as separate planes).
237 */
238tsize_t
239TIFFRasterScanlineSize(TIFF* tif)
240{
241 TIFFDirectory *td = &tif->tif_dir;
242 tsize_t scanline;
243
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244 scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
245 "TIFFRasterScanlineSize");
b47c832e 246 if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
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247 scanline = multiply (tif, scanline, td->td_samplesperpixel,
248 "TIFFRasterScanlineSize");
249 return ((tsize_t) TIFFhowmany8(scanline));
b47c832e 250 } else
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251 return ((tsize_t) multiply (tif, TIFFhowmany8(scanline),
252 td->td_samplesperpixel,
253 "TIFFRasterScanlineSize"));
b47c832e 254}