1/* $Id: tif_strip.c,v 1.19.2.1 2010-06-08 18:50:43 bfriesen Exp $ */
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
34static uint32
35summarize(TIFF* tif, size_t summand1, size_t summand2, const char* where)
36{
37	/*
38	 * XXX: We are using casting to uint32 here, bacause sizeof(size_t)
39	 * may be larger than sizeof(uint32) on 64-bit architectures.
40	 */
41	uint32	bytes = summand1 + summand2;
42
43	if (bytes - summand1 != summand2) {
44		TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "Integer overflow in %s", where);
45		bytes = 0;
46	}
47
48	return (bytes);
49}
50
51static uint32
52multiply(TIFF* tif, size_t nmemb, size_t elem_size, const char* where)
53{
54	uint32	bytes = nmemb * elem_size;
55
56	if (elem_size && bytes / elem_size != nmemb) {
57		TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "Integer overflow in %s", where);
58		bytes = 0;
59	}
60
61	return (bytes);
62}
63
64/*
65 * Compute which strip a (row,sample) value is in.
66 */
67tstrip_t
68TIFFComputeStrip(TIFF* tif, uint32 row, tsample_t sample)
69{
70	TIFFDirectory *td = &tif->tif_dir;
71	tstrip_t strip;
72
73	strip = row / td->td_rowsperstrip;
74	if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
75		if (sample >= td->td_samplesperpixel) {
76			TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
77			    "%lu: Sample out of range, max %lu",
78			    (unsigned long) sample, (unsigned long) td->td_samplesperpixel);
79			return ((tstrip_t) 0);
80		}
81		strip += sample*td->td_stripsperimage;
82	}
83	return (strip);
84}
85
86/*
87 * Compute how many strips are in an image.
88 */
89tstrip_t
90TIFFNumberOfStrips(TIFF* tif)
91{
92	TIFFDirectory *td = &tif->tif_dir;
93	tstrip_t nstrips;
94
95	nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 :
96	     TIFFhowmany(td->td_imagelength, td->td_rowsperstrip));
97	if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
98		nstrips = multiply(tif, nstrips, td->td_samplesperpixel,
99				   "TIFFNumberOfStrips");
100	return (nstrips);
101}
102
103/*
104 * Compute the # bytes in a variable height, row-aligned strip.
105 */
106tsize_t
107TIFFVStripSize(TIFF* tif, uint32 nrows)
108{
109	TIFFDirectory *td = &tif->tif_dir;
110
111	if (nrows == (uint32) -1)
112		nrows = td->td_imagelength;
113	if (td->td_planarconfig == PLANARCONFIG_CONTIG &&
114	    td->td_photometric == PHOTOMETRIC_YCBCR &&
115	    !isUpSampled(tif)) {
116		/*
117		 * Packed YCbCr data contain one Cb+Cr for every
118		 * HorizontalSampling*VerticalSampling Y values.
119		 * Must also roundup width and height when calculating
120		 * since images that are not a multiple of the
121		 * horizontal/vertical subsampling area include
122		 * YCbCr data for the extended image.
123		 */
124		uint16 ycbcrsubsampling[2];
125		tsize_t w, scanline, samplingarea;
126
127		TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING,
128			      ycbcrsubsampling + 0,
129			      ycbcrsubsampling + 1 );
130
131		samplingarea = ycbcrsubsampling[0]*ycbcrsubsampling[1];
132		if (samplingarea == 0) {
133			TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
134				     "Invalid YCbCr subsampling");
135			return 0;
136		}
137
138		w = TIFFroundup(td->td_imagewidth, ycbcrsubsampling[0]);
139		scanline = TIFFhowmany8(multiply(tif, w, td->td_bitspersample,
140						 "TIFFVStripSize"));
141		nrows = TIFFroundup(nrows, ycbcrsubsampling[1]);
142		/* NB: don't need TIFFhowmany here 'cuz everything is rounded */
143		scanline = multiply(tif, nrows, scanline, "TIFFVStripSize");
144		return ((tsize_t)
145		    summarize(tif, scanline,
146			      multiply(tif, 2, scanline / samplingarea,
147				       "TIFFVStripSize"), "TIFFVStripSize"));
148	} else
149		return ((tsize_t) multiply(tif, nrows, TIFFScanlineSize(tif),
150					   "TIFFVStripSize"));
151}
152
153
154/*
155 * Compute the # bytes in a raw strip.
156 */
157tsize_t
158TIFFRawStripSize(TIFF* tif, tstrip_t strip)
159{
160	TIFFDirectory* td = &tif->tif_dir;
161	tsize_t bytecount = td->td_stripbytecount[strip];
162
163	if (bytecount <= 0) {
164		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
165			  "%lu: Invalid strip byte count, strip %lu",
166			  (unsigned long) bytecount, (unsigned long) strip);
167		bytecount = (tsize_t) -1;
168	}
169
170	return bytecount;
171}
172
173/*
174 * Compute the # bytes in a (row-aligned) strip.
175 *
176 * Note that if RowsPerStrip is larger than the
177 * recorded ImageLength, then the strip size is
178 * truncated to reflect the actual space required
179 * to hold the strip.
180 */
181tsize_t
182TIFFStripSize(TIFF* tif)
183{
184	TIFFDirectory* td = &tif->tif_dir;
185	uint32 rps = td->td_rowsperstrip;
186	if (rps > td->td_imagelength)
187		rps = td->td_imagelength;
188	return (TIFFVStripSize(tif, rps));
189}
190
191/*
192 * Compute a default strip size based on the image
193 * characteristics and a requested value.  If the
194 * request is <1 then we choose a strip size according
195 * to certain heuristics.
196 */
197uint32
198TIFFDefaultStripSize(TIFF* tif, uint32 request)
199{
200	return (*tif->tif_defstripsize)(tif, request);
201}
202
203uint32
204_TIFFDefaultStripSize(TIFF* tif, uint32 s)
205{
206	if ((int32) s < 1) {
207		/*
208		 * If RowsPerStrip is unspecified, try to break the
209		 * image up into strips that are approximately
210		 * STRIP_SIZE_DEFAULT bytes long.
211		 */
212		tsize_t scanline = TIFFScanlineSize(tif);
213		s = (uint32)STRIP_SIZE_DEFAULT / (scanline == 0 ? 1 : scanline);
214		if (s == 0)		/* very wide images */
215			s = 1;
216	}
217	return (s);
218}
219
220/*
221 * Return the number of bytes to read/write in a call to
222 * one of the scanline-oriented i/o routines.  Note that
223 * this number may be 1/samples-per-pixel if data is
224 * stored as separate planes.
225 */
226tsize_t
227TIFFScanlineSize(TIFF* tif)
228{
229	TIFFDirectory *td = &tif->tif_dir;
230	tsize_t scanline;
231
232	if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
233		if (td->td_photometric == PHOTOMETRIC_YCBCR
234		    && !isUpSampled(tif)) {
235			uint16 ycbcrsubsampling[2];
236
237			TIFFGetField(tif, TIFFTAG_YCBCRSUBSAMPLING,
238				     ycbcrsubsampling + 0,
239				     ycbcrsubsampling + 1);
240
241			if (ycbcrsubsampling[0] == 0) {
242				TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
243					     "Invalid YCbCr subsampling");
244				return 0;
245			}
246
247			scanline = TIFFroundup(td->td_imagewidth,
248					       ycbcrsubsampling[0]);
249			scanline = TIFFhowmany8(multiply(tif, scanline,
250							 td->td_bitspersample,
251							 "TIFFScanlineSize"));
252			return ((tsize_t)
253				summarize(tif, scanline,
254					  multiply(tif, 2,
255						scanline / ycbcrsubsampling[0],
256						"TIFFVStripSize"),
257					  "TIFFVStripSize"));
258		} else {
259			scanline = multiply(tif, td->td_imagewidth,
260					    td->td_samplesperpixel,
261					    "TIFFScanlineSize");
262		}
263	} else
264		scanline = td->td_imagewidth;
265	return ((tsize_t) TIFFhowmany8(multiply(tif, scanline,
266						td->td_bitspersample,
267						"TIFFScanlineSize")));
268}
269
270/*
271 * Some stuff depends on this older version of TIFFScanlineSize
272 * TODO: resolve this
273 */
274tsize_t
275TIFFOldScanlineSize(TIFF* tif)
276{
277	TIFFDirectory *td = &tif->tif_dir;
278	tsize_t scanline;
279
280	scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
281			     "TIFFScanlineSize");
282	if (td->td_planarconfig == PLANARCONFIG_CONTIG)
283		scanline = multiply (tif, scanline, td->td_samplesperpixel,
284				     "TIFFScanlineSize");
285	return ((tsize_t) TIFFhowmany8(scanline));
286}
287
288/*
289 * Return the number of bytes to read/write in a call to
290 * one of the scanline-oriented i/o routines.  Note that
291 * this number may be 1/samples-per-pixel if data is
292 * stored as separate planes.
293 * The ScanlineSize in case of YCbCrSubsampling is defined as the
294 * strip size divided by the strip height, i.e. the size of a pack of vertical
295 * subsampling lines divided by vertical subsampling. It should thus make
296 * sense when multiplied by a multiple of vertical subsampling.
297 * Some stuff depends on this newer version of TIFFScanlineSize
298 * TODO: resolve this
299 */
300tsize_t
301TIFFNewScanlineSize(TIFF* tif)
302{
303	TIFFDirectory *td = &tif->tif_dir;
304	tsize_t scanline;
305
306	if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
307		if (td->td_photometric == PHOTOMETRIC_YCBCR
308		    && !isUpSampled(tif)) {
309			uint16 ycbcrsubsampling[2];
310
311			TIFFGetField(tif, TIFFTAG_YCBCRSUBSAMPLING,
312				     ycbcrsubsampling + 0,
313				     ycbcrsubsampling + 1);
314
315			if (ycbcrsubsampling[0]*ycbcrsubsampling[1] == 0) {
316				TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
317					     "Invalid YCbCr subsampling");
318				return 0;
319			}
320
321			return((tsize_t) ((((td->td_imagewidth+ycbcrsubsampling[0]-1)
322					    /ycbcrsubsampling[0])
323					   *(ycbcrsubsampling[0]*ycbcrsubsampling[1]+2)
324					   *td->td_bitspersample+7)
325					  /8)/ycbcrsubsampling[1]);
326
327		} else {
328			scanline = multiply(tif, td->td_imagewidth,
329					    td->td_samplesperpixel,
330					    "TIFFScanlineSize");
331		}
332	} else
333		scanline = td->td_imagewidth;
334	return ((tsize_t) TIFFhowmany8(multiply(tif, scanline,
335						td->td_bitspersample,
336						"TIFFScanlineSize")));
337}
338
339/*
340 * Return the number of bytes required to store a complete
341 * decoded and packed raster scanline (as opposed to the
342 * I/O size returned by TIFFScanlineSize which may be less
343 * if data is store as separate planes).
344 */
345tsize_t
346TIFFRasterScanlineSize(TIFF* tif)
347{
348	TIFFDirectory *td = &tif->tif_dir;
349	tsize_t scanline;
350
351	scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
352			     "TIFFRasterScanlineSize");
353	if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
354		scanline = multiply (tif, scanline, td->td_samplesperpixel,
355				     "TIFFRasterScanlineSize");
356		return ((tsize_t) TIFFhowmany8(scanline));
357	} else
358		return ((tsize_t) multiply (tif, TIFFhowmany8(scanline),
359					    td->td_samplesperpixel,
360					    "TIFFRasterScanlineSize"));
361}
362
363/* vim: set ts=8 sts=8 sw=8 noet: */
364/*
365 * Local Variables:
366 * mode: c
367 * c-basic-offset: 8
368 * fill-column: 78
369 * End:
370 */
371