VirtualBox

source: vbox/trunk/src/libs/libpng-1.6.36/pngwrite.c@ 78251

Last change on this file since 78251 was 76030, checked in by vboxsync, 6 years ago

libpng-1.6.36: properly export to OSE, and while at it fix EOL style for shell scripts

  • Property svn:eol-style set to native
File size: 74.8 KB
Line 
1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * Copyright (c) 2018 Cosmin Truta
5 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
6 * Copyright (c) 1996-1997 Andreas Dilger
7 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14#include "pngpriv.h"
15#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
16# include <errno.h>
17#endif /* SIMPLIFIED_WRITE_STDIO */
18
19#ifdef PNG_WRITE_SUPPORTED
20
21#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
22/* Write out all the unknown chunks for the current given location */
23static void
24write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
25 unsigned int where)
26{
27 if (info_ptr->unknown_chunks_num != 0)
28 {
29 png_const_unknown_chunkp up;
30
31 png_debug(5, "writing extra chunks");
32
33 for (up = info_ptr->unknown_chunks;
34 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
35 ++up)
36 if ((up->location & where) != 0)
37 {
38 /* If per-chunk unknown chunk handling is enabled use it, otherwise
39 * just write the chunks the application has set.
40 */
41#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
42 int keep = png_handle_as_unknown(png_ptr, up->name);
43
44 /* NOTE: this code is radically different from the read side in the
45 * matter of handling an ancillary unknown chunk. In the read side
46 * the default behavior is to discard it, in the code below the default
47 * behavior is to write it. Critical chunks are, however, only
48 * written if explicitly listed or if the default is set to write all
49 * unknown chunks.
50 *
51 * The default handling is also slightly weird - it is not possible to
52 * stop the writing of all unsafe-to-copy chunks!
53 *
54 * TODO: REVIEW: this would seem to be a bug.
55 */
56 if (keep != PNG_HANDLE_CHUNK_NEVER &&
57 ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
58 keep == PNG_HANDLE_CHUNK_ALWAYS ||
59 (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
60 png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
61#endif
62 {
63 /* TODO: review, what is wrong with a zero length unknown chunk? */
64 if (up->size == 0)
65 png_warning(png_ptr, "Writing zero-length unknown chunk");
66
67 png_write_chunk(png_ptr, up->name, up->data, up->size);
68 }
69 }
70 }
71}
72#endif /* WRITE_UNKNOWN_CHUNKS */
73
74/* Writes all the PNG information. This is the suggested way to use the
75 * library. If you have a new chunk to add, make a function to write it,
76 * and put it in the correct location here. If you want the chunk written
77 * after the image data, put it in png_write_end(). I strongly encourage
78 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
79 * the chunk, as that will keep the code from breaking if you want to just
80 * write a plain PNG file. If you have long comments, I suggest writing
81 * them in png_write_end(), and compressing them.
82 */
83void PNGAPI
84png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
85{
86 png_debug(1, "in png_write_info_before_PLTE");
87
88 if (png_ptr == NULL || info_ptr == NULL)
89 return;
90
91 if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
92 {
93 /* Write PNG signature */
94 png_write_sig(png_ptr);
95
96#ifdef PNG_MNG_FEATURES_SUPPORTED
97 if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \
98 png_ptr->mng_features_permitted != 0)
99 {
100 png_warning(png_ptr,
101 "MNG features are not allowed in a PNG datastream");
102 png_ptr->mng_features_permitted = 0;
103 }
104#endif
105
106 /* Write IHDR information. */
107 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
108 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
109 info_ptr->filter_type,
110#ifdef PNG_WRITE_INTERLACING_SUPPORTED
111 info_ptr->interlace_type
112#else
113 0
114#endif
115 );
116
117 /* The rest of these check to see if the valid field has the appropriate
118 * flag set, and if it does, writes the chunk.
119 *
120 * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
121 * the chunks will be written if the WRITE routine is there and
122 * information * is available in the COLORSPACE. (See
123 * png_colorspace_sync_info in png.c for where the valid flags get set.)
124 *
125 * Under certain circumstances the colorspace can be invalidated without
126 * syncing the info_struct 'valid' flags; this happens if libpng detects
127 * an error and calls png_error while the color space is being set, yet
128 * the application continues writing the PNG. So check the 'invalid'
129 * flag here too.
130 */
131#ifdef PNG_GAMMA_SUPPORTED
132# ifdef PNG_WRITE_gAMA_SUPPORTED
133 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
134 (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 &&
135 (info_ptr->valid & PNG_INFO_gAMA) != 0)
136 png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
137# endif
138#endif
139
140#ifdef PNG_COLORSPACE_SUPPORTED
141 /* Write only one of sRGB or an ICC profile. If a profile was supplied
142 * and it matches one of the known sRGB ones issue a warning.
143 */
144# ifdef PNG_WRITE_iCCP_SUPPORTED
145 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
146 (info_ptr->valid & PNG_INFO_iCCP) != 0)
147 {
148# ifdef PNG_WRITE_sRGB_SUPPORTED
149 if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
150 png_app_warning(png_ptr,
151 "profile matches sRGB but writing iCCP instead");
152# endif
153
154 png_write_iCCP(png_ptr, info_ptr->iccp_name,
155 info_ptr->iccp_profile);
156 }
157# ifdef PNG_WRITE_sRGB_SUPPORTED
158 else
159# endif
160# endif
161
162# ifdef PNG_WRITE_sRGB_SUPPORTED
163 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
164 (info_ptr->valid & PNG_INFO_sRGB) != 0)
165 png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
166# endif /* WRITE_sRGB */
167#endif /* COLORSPACE */
168
169#ifdef PNG_WRITE_sBIT_SUPPORTED
170 if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
171 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
172#endif
173
174#ifdef PNG_COLORSPACE_SUPPORTED
175# ifdef PNG_WRITE_cHRM_SUPPORTED
176 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
177 (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 &&
178 (info_ptr->valid & PNG_INFO_cHRM) != 0)
179 png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
180# endif
181#endif
182
183#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
184 write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
185#endif
186
187 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
188 }
189}
190
191void PNGAPI
192png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
193{
194#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
195 int i;
196#endif
197
198 png_debug(1, "in png_write_info");
199
200 if (png_ptr == NULL || info_ptr == NULL)
201 return;
202
203 png_write_info_before_PLTE(png_ptr, info_ptr);
204
205 if ((info_ptr->valid & PNG_INFO_PLTE) != 0)
206 png_write_PLTE(png_ptr, info_ptr->palette,
207 (png_uint_32)info_ptr->num_palette);
208
209 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
210 png_error(png_ptr, "Valid palette required for paletted images");
211
212#ifdef PNG_WRITE_tRNS_SUPPORTED
213 if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
214 {
215#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
216 /* Invert the alpha channel (in tRNS) */
217 if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 &&
218 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
219 {
220 int j, jend;
221
222 jend = info_ptr->num_trans;
223 if (jend > PNG_MAX_PALETTE_LENGTH)
224 jend = PNG_MAX_PALETTE_LENGTH;
225
226 for (j = 0; j<jend; ++j)
227 info_ptr->trans_alpha[j] =
228 (png_byte)(255 - info_ptr->trans_alpha[j]);
229 }
230#endif
231 png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
232 info_ptr->num_trans, info_ptr->color_type);
233 }
234#endif
235#ifdef PNG_WRITE_bKGD_SUPPORTED
236 if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
237 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
238#endif
239
240#ifdef PNG_WRITE_eXIf_SUPPORTED
241 if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
242 png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
243#endif
244
245#ifdef PNG_WRITE_hIST_SUPPORTED
246 if ((info_ptr->valid & PNG_INFO_hIST) != 0)
247 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
248#endif
249
250#ifdef PNG_WRITE_oFFs_SUPPORTED
251 if ((info_ptr->valid & PNG_INFO_oFFs) != 0)
252 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
253 info_ptr->offset_unit_type);
254#endif
255
256#ifdef PNG_WRITE_pCAL_SUPPORTED
257 if ((info_ptr->valid & PNG_INFO_pCAL) != 0)
258 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
259 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
260 info_ptr->pcal_units, info_ptr->pcal_params);
261#endif
262
263#ifdef PNG_WRITE_sCAL_SUPPORTED
264 if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
265 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
266 info_ptr->scal_s_width, info_ptr->scal_s_height);
267#endif /* sCAL */
268
269#ifdef PNG_WRITE_pHYs_SUPPORTED
270 if ((info_ptr->valid & PNG_INFO_pHYs) != 0)
271 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
272 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
273#endif /* pHYs */
274
275#ifdef PNG_WRITE_tIME_SUPPORTED
276 if ((info_ptr->valid & PNG_INFO_tIME) != 0)
277 {
278 png_write_tIME(png_ptr, &(info_ptr->mod_time));
279 png_ptr->mode |= PNG_WROTE_tIME;
280 }
281#endif /* tIME */
282
283#ifdef PNG_WRITE_sPLT_SUPPORTED
284 if ((info_ptr->valid & PNG_INFO_sPLT) != 0)
285 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
286 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
287#endif /* sPLT */
288
289#ifdef PNG_WRITE_TEXT_SUPPORTED
290 /* Check to see if we need to write text chunks */
291 for (i = 0; i < info_ptr->num_text; i++)
292 {
293 png_debug2(2, "Writing header text chunk %d, type %d", i,
294 info_ptr->text[i].compression);
295 /* An internationalized chunk? */
296 if (info_ptr->text[i].compression > 0)
297 {
298#ifdef PNG_WRITE_iTXt_SUPPORTED
299 /* Write international chunk */
300 png_write_iTXt(png_ptr,
301 info_ptr->text[i].compression,
302 info_ptr->text[i].key,
303 info_ptr->text[i].lang,
304 info_ptr->text[i].lang_key,
305 info_ptr->text[i].text);
306 /* Mark this chunk as written */
307 if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
308 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
309 else
310 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
311#else
312 png_warning(png_ptr, "Unable to write international text");
313#endif
314 }
315
316 /* If we want a compressed text chunk */
317 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
318 {
319#ifdef PNG_WRITE_zTXt_SUPPORTED
320 /* Write compressed chunk */
321 png_write_zTXt(png_ptr, info_ptr->text[i].key,
322 info_ptr->text[i].text, info_ptr->text[i].compression);
323 /* Mark this chunk as written */
324 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
325#else
326 png_warning(png_ptr, "Unable to write compressed text");
327#endif
328 }
329
330 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
331 {
332#ifdef PNG_WRITE_tEXt_SUPPORTED
333 /* Write uncompressed chunk */
334 png_write_tEXt(png_ptr, info_ptr->text[i].key,
335 info_ptr->text[i].text,
336 0);
337 /* Mark this chunk as written */
338 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
339#else
340 /* Can't get here */
341 png_warning(png_ptr, "Unable to write uncompressed text");
342#endif
343 }
344 }
345#endif /* tEXt */
346
347#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
348 write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
349#endif
350}
351
352/* Writes the end of the PNG file. If you don't want to write comments or
353 * time information, you can pass NULL for info. If you already wrote these
354 * in png_write_info(), do not write them again here. If you have long
355 * comments, I suggest writing them here, and compressing them.
356 */
357void PNGAPI
358png_write_end(png_structrp png_ptr, png_inforp info_ptr)
359{
360 png_debug(1, "in png_write_end");
361
362 if (png_ptr == NULL)
363 return;
364
365 if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
366 png_error(png_ptr, "No IDATs written into file");
367
368#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
369 if (png_ptr->num_palette_max > png_ptr->num_palette)
370 png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
371#endif
372
373 /* See if user wants us to write information chunks */
374 if (info_ptr != NULL)
375 {
376#ifdef PNG_WRITE_TEXT_SUPPORTED
377 int i; /* local index variable */
378#endif
379#ifdef PNG_WRITE_tIME_SUPPORTED
380 /* Check to see if user has supplied a time chunk */
381 if ((info_ptr->valid & PNG_INFO_tIME) != 0 &&
382 (png_ptr->mode & PNG_WROTE_tIME) == 0)
383 png_write_tIME(png_ptr, &(info_ptr->mod_time));
384
385#endif
386#ifdef PNG_WRITE_TEXT_SUPPORTED
387 /* Loop through comment chunks */
388 for (i = 0; i < info_ptr->num_text; i++)
389 {
390 png_debug2(2, "Writing trailer text chunk %d, type %d", i,
391 info_ptr->text[i].compression);
392 /* An internationalized chunk? */
393 if (info_ptr->text[i].compression > 0)
394 {
395#ifdef PNG_WRITE_iTXt_SUPPORTED
396 /* Write international chunk */
397 png_write_iTXt(png_ptr,
398 info_ptr->text[i].compression,
399 info_ptr->text[i].key,
400 info_ptr->text[i].lang,
401 info_ptr->text[i].lang_key,
402 info_ptr->text[i].text);
403 /* Mark this chunk as written */
404 if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
405 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
406 else
407 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
408#else
409 png_warning(png_ptr, "Unable to write international text");
410#endif
411 }
412
413 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
414 {
415#ifdef PNG_WRITE_zTXt_SUPPORTED
416 /* Write compressed chunk */
417 png_write_zTXt(png_ptr, info_ptr->text[i].key,
418 info_ptr->text[i].text, info_ptr->text[i].compression);
419 /* Mark this chunk as written */
420 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
421#else
422 png_warning(png_ptr, "Unable to write compressed text");
423#endif
424 }
425
426 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
427 {
428#ifdef PNG_WRITE_tEXt_SUPPORTED
429 /* Write uncompressed chunk */
430 png_write_tEXt(png_ptr, info_ptr->text[i].key,
431 info_ptr->text[i].text, 0);
432 /* Mark this chunk as written */
433 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
434#else
435 png_warning(png_ptr, "Unable to write uncompressed text");
436#endif
437 }
438 }
439#endif
440
441#ifdef PNG_WRITE_eXIf_SUPPORTED
442 if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
443 png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
444#endif
445
446#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
447 write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
448#endif
449 }
450
451 png_ptr->mode |= PNG_AFTER_IDAT;
452
453 /* Write end of PNG file */
454 png_write_IEND(png_ptr);
455
456 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
457 * and restored again in libpng-1.2.30, may cause some applications that
458 * do not set png_ptr->output_flush_fn to crash. If your application
459 * experiences a problem, please try building libpng with
460 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
461 * png-mng-implement at lists.sf.net .
462 */
463#ifdef PNG_WRITE_FLUSH_SUPPORTED
464# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
465 png_flush(png_ptr);
466# endif
467#endif
468}
469
470#ifdef PNG_CONVERT_tIME_SUPPORTED
471void PNGAPI
472png_convert_from_struct_tm(png_timep ptime, const struct tm * ttime)
473{
474 png_debug(1, "in png_convert_from_struct_tm");
475
476 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
477 ptime->month = (png_byte)(ttime->tm_mon + 1);
478 ptime->day = (png_byte)ttime->tm_mday;
479 ptime->hour = (png_byte)ttime->tm_hour;
480 ptime->minute = (png_byte)ttime->tm_min;
481 ptime->second = (png_byte)ttime->tm_sec;
482}
483
484void PNGAPI
485png_convert_from_time_t(png_timep ptime, time_t ttime)
486{
487 struct tm *tbuf;
488
489 png_debug(1, "in png_convert_from_time_t");
490
491 tbuf = gmtime(&ttime);
492 png_convert_from_struct_tm(ptime, tbuf);
493}
494#endif
495
496/* Initialize png_ptr structure, and allocate any memory needed */
497PNG_FUNCTION(png_structp,PNGAPI
498png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
499 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
500{
501#ifndef PNG_USER_MEM_SUPPORTED
502 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
503 error_fn, warn_fn, NULL, NULL, NULL);
504#else
505 return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
506 warn_fn, NULL, NULL, NULL);
507}
508
509/* Alternate initialize png_ptr structure, and allocate any memory needed */
510PNG_FUNCTION(png_structp,PNGAPI
511png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
512 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
513 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
514{
515 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
516 error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
517#endif /* USER_MEM */
518 if (png_ptr != NULL)
519 {
520 /* Set the zlib control values to defaults; they can be overridden by the
521 * application after the struct has been created.
522 */
523 png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
524
525 /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
526 * pngwutil.c defaults it according to whether or not filters will be
527 * used, and ignores this setting.
528 */
529 png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
530 png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
531 png_ptr->zlib_mem_level = 8;
532 png_ptr->zlib_window_bits = 15;
533 png_ptr->zlib_method = 8;
534
535#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
536 png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
537 png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
538 png_ptr->zlib_text_mem_level = 8;
539 png_ptr->zlib_text_window_bits = 15;
540 png_ptr->zlib_text_method = 8;
541#endif /* WRITE_COMPRESSED_TEXT */
542
543 /* This is a highly dubious configuration option; by default it is off,
544 * but it may be appropriate for private builds that are testing
545 * extensions not conformant to the current specification, or of
546 * applications that must not fail to write at all costs!
547 */
548#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
549 /* In stable builds only warn if an application error can be completely
550 * handled.
551 */
552 png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
553#endif
554
555 /* App warnings are warnings in release (or release candidate) builds but
556 * are errors during development.
557 */
558#if PNG_RELEASE_BUILD
559 png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
560#endif
561
562 /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
563 * do it itself) avoiding setting the default function if it is not
564 * required.
565 */
566 png_set_write_fn(png_ptr, NULL, NULL, NULL);
567 }
568
569 return png_ptr;
570}
571
572
573/* Write a few rows of image data. If the image is interlaced,
574 * either you will have to write the 7 sub images, or, if you
575 * have called png_set_interlace_handling(), you will have to
576 * "write" the image seven times.
577 */
578void PNGAPI
579png_write_rows(png_structrp png_ptr, png_bytepp row,
580 png_uint_32 num_rows)
581{
582 png_uint_32 i; /* row counter */
583 png_bytepp rp; /* row pointer */
584
585 png_debug(1, "in png_write_rows");
586
587 if (png_ptr == NULL)
588 return;
589
590 /* Loop through the rows */
591 for (i = 0, rp = row; i < num_rows; i++, rp++)
592 {
593 png_write_row(png_ptr, *rp);
594 }
595}
596
597/* Write the image. You only need to call this function once, even
598 * if you are writing an interlaced image.
599 */
600void PNGAPI
601png_write_image(png_structrp png_ptr, png_bytepp image)
602{
603 png_uint_32 i; /* row index */
604 int pass, num_pass; /* pass variables */
605 png_bytepp rp; /* points to current row */
606
607 if (png_ptr == NULL)
608 return;
609
610 png_debug(1, "in png_write_image");
611
612#ifdef PNG_WRITE_INTERLACING_SUPPORTED
613 /* Initialize interlace handling. If image is not interlaced,
614 * this will set pass to 1
615 */
616 num_pass = png_set_interlace_handling(png_ptr);
617#else
618 num_pass = 1;
619#endif
620 /* Loop through passes */
621 for (pass = 0; pass < num_pass; pass++)
622 {
623 /* Loop through image */
624 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
625 {
626 png_write_row(png_ptr, *rp);
627 }
628 }
629}
630
631#ifdef PNG_MNG_FEATURES_SUPPORTED
632/* Performs intrapixel differencing */
633static void
634png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
635{
636 png_debug(1, "in png_do_write_intrapixel");
637
638 if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
639 {
640 int bytes_per_pixel;
641 png_uint_32 row_width = row_info->width;
642 if (row_info->bit_depth == 8)
643 {
644 png_bytep rp;
645 png_uint_32 i;
646
647 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
648 bytes_per_pixel = 3;
649
650 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
651 bytes_per_pixel = 4;
652
653 else
654 return;
655
656 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
657 {
658 *(rp) = (png_byte)(*rp - *(rp + 1));
659 *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1));
660 }
661 }
662
663#ifdef PNG_WRITE_16BIT_SUPPORTED
664 else if (row_info->bit_depth == 16)
665 {
666 png_bytep rp;
667 png_uint_32 i;
668
669 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
670 bytes_per_pixel = 6;
671
672 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
673 bytes_per_pixel = 8;
674
675 else
676 return;
677
678 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
679 {
680 png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1);
681 png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3);
682 png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5);
683 png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
684 png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
685 *(rp ) = (png_byte)(red >> 8);
686 *(rp + 1) = (png_byte)red;
687 *(rp + 4) = (png_byte)(blue >> 8);
688 *(rp + 5) = (png_byte)blue;
689 }
690 }
691#endif /* WRITE_16BIT */
692 }
693}
694#endif /* MNG_FEATURES */
695
696/* Called by user to write a row of image data */
697void PNGAPI
698png_write_row(png_structrp png_ptr, png_const_bytep row)
699{
700 /* 1.5.6: moved from png_struct to be a local structure: */
701 png_row_info row_info;
702
703 if (png_ptr == NULL)
704 return;
705
706 png_debug2(1, "in png_write_row (row %u, pass %d)",
707 png_ptr->row_number, png_ptr->pass);
708
709 /* Initialize transformations and other stuff if first time */
710 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
711 {
712 /* Make sure we wrote the header info */
713 if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
714 png_error(png_ptr,
715 "png_write_info was never called before png_write_row");
716
717 /* Check for transforms that have been set but were defined out */
718#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
719 if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
720 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
721#endif
722
723#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
724 if ((png_ptr->transformations & PNG_FILLER) != 0)
725 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
726#endif
727#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
728 defined(PNG_READ_PACKSWAP_SUPPORTED)
729 if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
730 png_warning(png_ptr,
731 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
732#endif
733
734#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
735 if ((png_ptr->transformations & PNG_PACK) != 0)
736 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
737#endif
738
739#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
740 if ((png_ptr->transformations & PNG_SHIFT) != 0)
741 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
742#endif
743
744#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
745 if ((png_ptr->transformations & PNG_BGR) != 0)
746 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
747#endif
748
749#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
750 if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
751 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
752#endif
753
754 png_write_start_row(png_ptr);
755 }
756
757#ifdef PNG_WRITE_INTERLACING_SUPPORTED
758 /* If interlaced and not interested in row, return */
759 if (png_ptr->interlaced != 0 &&
760 (png_ptr->transformations & PNG_INTERLACE) != 0)
761 {
762 switch (png_ptr->pass)
763 {
764 case 0:
765 if ((png_ptr->row_number & 0x07) != 0)
766 {
767 png_write_finish_row(png_ptr);
768 return;
769 }
770 break;
771
772 case 1:
773 if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5)
774 {
775 png_write_finish_row(png_ptr);
776 return;
777 }
778 break;
779
780 case 2:
781 if ((png_ptr->row_number & 0x07) != 4)
782 {
783 png_write_finish_row(png_ptr);
784 return;
785 }
786 break;
787
788 case 3:
789 if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3)
790 {
791 png_write_finish_row(png_ptr);
792 return;
793 }
794 break;
795
796 case 4:
797 if ((png_ptr->row_number & 0x03) != 2)
798 {
799 png_write_finish_row(png_ptr);
800 return;
801 }
802 break;
803
804 case 5:
805 if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2)
806 {
807 png_write_finish_row(png_ptr);
808 return;
809 }
810 break;
811
812 case 6:
813 if ((png_ptr->row_number & 0x01) == 0)
814 {
815 png_write_finish_row(png_ptr);
816 return;
817 }
818 break;
819
820 default: /* error: ignore it */
821 break;
822 }
823 }
824#endif
825
826 /* Set up row info for transformations */
827 row_info.color_type = png_ptr->color_type;
828 row_info.width = png_ptr->usr_width;
829 row_info.channels = png_ptr->usr_channels;
830 row_info.bit_depth = png_ptr->usr_bit_depth;
831 row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
832 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
833
834 png_debug1(3, "row_info->color_type = %d", row_info.color_type);
835 png_debug1(3, "row_info->width = %u", row_info.width);
836 png_debug1(3, "row_info->channels = %d", row_info.channels);
837 png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
838 png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
839 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
840
841 /* Copy user's row into buffer, leaving room for filter byte. */
842 memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
843
844#ifdef PNG_WRITE_INTERLACING_SUPPORTED
845 /* Handle interlacing */
846 if (png_ptr->interlaced && png_ptr->pass < 6 &&
847 (png_ptr->transformations & PNG_INTERLACE) != 0)
848 {
849 png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
850 /* This should always get caught above, but still ... */
851 if (row_info.width == 0)
852 {
853 png_write_finish_row(png_ptr);
854 return;
855 }
856 }
857#endif
858
859#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
860 /* Handle other transformations */
861 if (png_ptr->transformations != 0)
862 png_do_write_transformations(png_ptr, &row_info);
863#endif
864
865 /* At this point the row_info pixel depth must match the 'transformed' depth,
866 * which is also the output depth.
867 */
868 if (row_info.pixel_depth != png_ptr->pixel_depth ||
869 row_info.pixel_depth != png_ptr->transformed_pixel_depth)
870 png_error(png_ptr, "internal write transform logic error");
871
872#ifdef PNG_MNG_FEATURES_SUPPORTED
873 /* Write filter_method 64 (intrapixel differencing) only if
874 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
875 * 2. Libpng did not write a PNG signature (this filter_method is only
876 * used in PNG datastreams that are embedded in MNG datastreams) and
877 * 3. The application called png_permit_mng_features with a mask that
878 * included PNG_FLAG_MNG_FILTER_64 and
879 * 4. The filter_method is 64 and
880 * 5. The color_type is RGB or RGBA
881 */
882 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
883 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
884 {
885 /* Intrapixel differencing */
886 png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
887 }
888#endif
889
890/* Added at libpng-1.5.10 */
891#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
892 /* Check for out-of-range palette index */
893 if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
894 png_ptr->num_palette_max >= 0)
895 png_do_check_palette_indexes(png_ptr, &row_info);
896#endif
897
898 /* Find a filter if necessary, filter the row and write it out. */
899 png_write_find_filter(png_ptr, &row_info);
900
901 if (png_ptr->write_row_fn != NULL)
902 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
903}
904
905#ifdef PNG_WRITE_FLUSH_SUPPORTED
906/* Set the automatic flush interval or 0 to turn flushing off */
907void PNGAPI
908png_set_flush(png_structrp png_ptr, int nrows)
909{
910 png_debug(1, "in png_set_flush");
911
912 if (png_ptr == NULL)
913 return;
914
915 png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows);
916}
917
918/* Flush the current output buffers now */
919void PNGAPI
920png_write_flush(png_structrp png_ptr)
921{
922 png_debug(1, "in png_write_flush");
923
924 if (png_ptr == NULL)
925 return;
926
927 /* We have already written out all of the data */
928 if (png_ptr->row_number >= png_ptr->num_rows)
929 return;
930
931 png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
932 png_ptr->flush_rows = 0;
933 png_flush(png_ptr);
934}
935#endif /* WRITE_FLUSH */
936
937/* Free any memory used in png_ptr struct without freeing the struct itself. */
938static void
939png_write_destroy(png_structrp png_ptr)
940{
941 png_debug(1, "in png_write_destroy");
942
943 /* Free any memory zlib uses */
944 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
945 deflateEnd(&png_ptr->zstream);
946
947 /* Free our memory. png_free checks NULL for us. */
948 png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
949 png_free(png_ptr, png_ptr->row_buf);
950 png_ptr->row_buf = NULL;
951#ifdef PNG_READ_EXPANDED_SUPPORTED
952 png_free(png_ptr, png_ptr->riffled_palette);
953 png_ptr->riffled_palette = NULL;
954#endif
955#ifdef PNG_WRITE_FILTER_SUPPORTED
956 png_free(png_ptr, png_ptr->prev_row);
957 png_free(png_ptr, png_ptr->try_row);
958 png_free(png_ptr, png_ptr->tst_row);
959 png_ptr->prev_row = NULL;
960 png_ptr->try_row = NULL;
961 png_ptr->tst_row = NULL;
962#endif
963
964#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
965 png_free(png_ptr, png_ptr->chunk_list);
966 png_ptr->chunk_list = NULL;
967#endif
968
969 /* The error handling and memory handling information is left intact at this
970 * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
971 * for how this happens.
972 */
973}
974
975/* Free all memory used by the write.
976 * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
977 * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
978 * the passed in info_structs but it would quietly fail to free any of the data
979 * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
980 * has no png_ptr.)
981 */
982void PNGAPI
983png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
984{
985 png_debug(1, "in png_destroy_write_struct");
986
987 if (png_ptr_ptr != NULL)
988 {
989 png_structrp png_ptr = *png_ptr_ptr;
990
991 if (png_ptr != NULL) /* added in libpng 1.6.0 */
992 {
993 png_destroy_info_struct(png_ptr, info_ptr_ptr);
994
995 *png_ptr_ptr = NULL;
996 png_write_destroy(png_ptr);
997 png_destroy_png_struct(png_ptr);
998 }
999 }
1000}
1001
1002/* Allow the application to select one or more row filters to use. */
1003void PNGAPI
1004png_set_filter(png_structrp png_ptr, int method, int filters)
1005{
1006 png_debug(1, "in png_set_filter");
1007
1008 if (png_ptr == NULL)
1009 return;
1010
1011#ifdef PNG_MNG_FEATURES_SUPPORTED
1012 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
1013 (method == PNG_INTRAPIXEL_DIFFERENCING))
1014 method = PNG_FILTER_TYPE_BASE;
1015
1016#endif
1017 if (method == PNG_FILTER_TYPE_BASE)
1018 {
1019 switch (filters & (PNG_ALL_FILTERS | 0x07))
1020 {
1021#ifdef PNG_WRITE_FILTER_SUPPORTED
1022 case 5:
1023 case 6:
1024 case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
1025#endif /* WRITE_FILTER */
1026 /* FALLTHROUGH */
1027 case PNG_FILTER_VALUE_NONE:
1028 png_ptr->do_filter = PNG_FILTER_NONE; break;
1029
1030#ifdef PNG_WRITE_FILTER_SUPPORTED
1031 case PNG_FILTER_VALUE_SUB:
1032 png_ptr->do_filter = PNG_FILTER_SUB; break;
1033
1034 case PNG_FILTER_VALUE_UP:
1035 png_ptr->do_filter = PNG_FILTER_UP; break;
1036
1037 case PNG_FILTER_VALUE_AVG:
1038 png_ptr->do_filter = PNG_FILTER_AVG; break;
1039
1040 case PNG_FILTER_VALUE_PAETH:
1041 png_ptr->do_filter = PNG_FILTER_PAETH; break;
1042
1043 default:
1044 png_ptr->do_filter = (png_byte)filters; break;
1045#else
1046 default:
1047 png_app_error(png_ptr, "Unknown row filter for method 0");
1048#endif /* WRITE_FILTER */
1049 }
1050
1051#ifdef PNG_WRITE_FILTER_SUPPORTED
1052 /* If we have allocated the row_buf, this means we have already started
1053 * with the image and we should have allocated all of the filter buffers
1054 * that have been selected. If prev_row isn't already allocated, then
1055 * it is too late to start using the filters that need it, since we
1056 * will be missing the data in the previous row. If an application
1057 * wants to start and stop using particular filters during compression,
1058 * it should start out with all of the filters, and then remove them
1059 * or add them back after the start of compression.
1060 *
1061 * NOTE: this is a nasty constraint on the code, because it means that the
1062 * prev_row buffer must be maintained even if there are currently no
1063 * 'prev_row' requiring filters active.
1064 */
1065 if (png_ptr->row_buf != NULL)
1066 {
1067 int num_filters;
1068 png_alloc_size_t buf_size;
1069
1070 /* Repeat the checks in png_write_start_row; 1 pixel high or wide
1071 * images cannot benefit from certain filters. If this isn't done here
1072 * the check below will fire on 1 pixel high images.
1073 */
1074 if (png_ptr->height == 1)
1075 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
1076
1077 if (png_ptr->width == 1)
1078 filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
1079
1080 if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
1081 && png_ptr->prev_row == NULL)
1082 {
1083 /* This is the error case, however it is benign - the previous row
1084 * is not available so the filter can't be used. Just warn here.
1085 */
1086 png_app_warning(png_ptr,
1087 "png_set_filter: UP/AVG/PAETH cannot be added after start");
1088 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
1089 }
1090
1091 num_filters = 0;
1092
1093 if (filters & PNG_FILTER_SUB)
1094 num_filters++;
1095
1096 if (filters & PNG_FILTER_UP)
1097 num_filters++;
1098
1099 if (filters & PNG_FILTER_AVG)
1100 num_filters++;
1101
1102 if (filters & PNG_FILTER_PAETH)
1103 num_filters++;
1104
1105 /* Allocate needed row buffers if they have not already been
1106 * allocated.
1107 */
1108 buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth,
1109 png_ptr->width) + 1;
1110
1111 if (png_ptr->try_row == NULL)
1112 png_ptr->try_row = png_voidcast(png_bytep,
1113 png_malloc(png_ptr, buf_size));
1114
1115 if (num_filters > 1)
1116 {
1117 if (png_ptr->tst_row == NULL)
1118 png_ptr->tst_row = png_voidcast(png_bytep,
1119 png_malloc(png_ptr, buf_size));
1120 }
1121 }
1122 png_ptr->do_filter = (png_byte)filters;
1123#endif
1124 }
1125 else
1126 png_error(png_ptr, "Unknown custom filter method");
1127}
1128
1129#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1130/* Provide floating and fixed point APIs */
1131#ifdef PNG_FLOATING_POINT_SUPPORTED
1132void PNGAPI
1133png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
1134 int num_weights, png_const_doublep filter_weights,
1135 png_const_doublep filter_costs)
1136{
1137 PNG_UNUSED(png_ptr)
1138 PNG_UNUSED(heuristic_method)
1139 PNG_UNUSED(num_weights)
1140 PNG_UNUSED(filter_weights)
1141 PNG_UNUSED(filter_costs)
1142}
1143#endif /* FLOATING_POINT */
1144
1145#ifdef PNG_FIXED_POINT_SUPPORTED
1146void PNGAPI
1147png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
1148 int num_weights, png_const_fixed_point_p filter_weights,
1149 png_const_fixed_point_p filter_costs)
1150{
1151 PNG_UNUSED(png_ptr)
1152 PNG_UNUSED(heuristic_method)
1153 PNG_UNUSED(num_weights)
1154 PNG_UNUSED(filter_weights)
1155 PNG_UNUSED(filter_costs)
1156}
1157#endif /* FIXED_POINT */
1158#endif /* WRITE_WEIGHTED_FILTER */
1159
1160#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1161void PNGAPI
1162png_set_compression_level(png_structrp png_ptr, int level)
1163{
1164 png_debug(1, "in png_set_compression_level");
1165
1166 if (png_ptr == NULL)
1167 return;
1168
1169 png_ptr->zlib_level = level;
1170}
1171
1172void PNGAPI
1173png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
1174{
1175 png_debug(1, "in png_set_compression_mem_level");
1176
1177 if (png_ptr == NULL)
1178 return;
1179
1180 png_ptr->zlib_mem_level = mem_level;
1181}
1182
1183void PNGAPI
1184png_set_compression_strategy(png_structrp png_ptr, int strategy)
1185{
1186 png_debug(1, "in png_set_compression_strategy");
1187
1188 if (png_ptr == NULL)
1189 return;
1190
1191 /* The flag setting here prevents the libpng dynamic selection of strategy.
1192 */
1193 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1194 png_ptr->zlib_strategy = strategy;
1195}
1196
1197/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1198 * smaller value of window_bits if it can do so safely.
1199 */
1200void PNGAPI
1201png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
1202{
1203 if (png_ptr == NULL)
1204 return;
1205
1206 /* Prior to 1.6.0 this would warn but then set the window_bits value. This
1207 * meant that negative window bits values could be selected that would cause
1208 * libpng to write a non-standard PNG file with raw deflate or gzip
1209 * compressed IDAT or ancillary chunks. Such files can be read and there is
1210 * no warning on read, so this seems like a very bad idea.
1211 */
1212 if (window_bits > 15)
1213 {
1214 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1215 window_bits = 15;
1216 }
1217
1218 else if (window_bits < 8)
1219 {
1220 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1221 window_bits = 8;
1222 }
1223
1224 png_ptr->zlib_window_bits = window_bits;
1225}
1226
1227void PNGAPI
1228png_set_compression_method(png_structrp png_ptr, int method)
1229{
1230 png_debug(1, "in png_set_compression_method");
1231
1232 if (png_ptr == NULL)
1233 return;
1234
1235 /* This would produce an invalid PNG file if it worked, but it doesn't and
1236 * deflate will fault it, so it is harmless to just warn here.
1237 */
1238 if (method != 8)
1239 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1240
1241 png_ptr->zlib_method = method;
1242}
1243#endif /* WRITE_CUSTOMIZE_COMPRESSION */
1244
1245/* The following were added to libpng-1.5.4 */
1246#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1247void PNGAPI
1248png_set_text_compression_level(png_structrp png_ptr, int level)
1249{
1250 png_debug(1, "in png_set_text_compression_level");
1251
1252 if (png_ptr == NULL)
1253 return;
1254
1255 png_ptr->zlib_text_level = level;
1256}
1257
1258void PNGAPI
1259png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
1260{
1261 png_debug(1, "in png_set_text_compression_mem_level");
1262
1263 if (png_ptr == NULL)
1264 return;
1265
1266 png_ptr->zlib_text_mem_level = mem_level;
1267}
1268
1269void PNGAPI
1270png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
1271{
1272 png_debug(1, "in png_set_text_compression_strategy");
1273
1274 if (png_ptr == NULL)
1275 return;
1276
1277 png_ptr->zlib_text_strategy = strategy;
1278}
1279
1280/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1281 * smaller value of window_bits if it can do so safely.
1282 */
1283void PNGAPI
1284png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
1285{
1286 if (png_ptr == NULL)
1287 return;
1288
1289 if (window_bits > 15)
1290 {
1291 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1292 window_bits = 15;
1293 }
1294
1295 else if (window_bits < 8)
1296 {
1297 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1298 window_bits = 8;
1299 }
1300
1301 png_ptr->zlib_text_window_bits = window_bits;
1302}
1303
1304void PNGAPI
1305png_set_text_compression_method(png_structrp png_ptr, int method)
1306{
1307 png_debug(1, "in png_set_text_compression_method");
1308
1309 if (png_ptr == NULL)
1310 return;
1311
1312 if (method != 8)
1313 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1314
1315 png_ptr->zlib_text_method = method;
1316}
1317#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1318/* end of API added to libpng-1.5.4 */
1319
1320void PNGAPI
1321png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
1322{
1323 if (png_ptr == NULL)
1324 return;
1325
1326 png_ptr->write_row_fn = write_row_fn;
1327}
1328
1329#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1330void PNGAPI
1331png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
1332 write_user_transform_fn)
1333{
1334 png_debug(1, "in png_set_write_user_transform_fn");
1335
1336 if (png_ptr == NULL)
1337 return;
1338
1339 png_ptr->transformations |= PNG_USER_TRANSFORM;
1340 png_ptr->write_user_transform_fn = write_user_transform_fn;
1341}
1342#endif
1343
1344
1345#ifdef PNG_INFO_IMAGE_SUPPORTED
1346void PNGAPI
1347png_write_png(png_structrp png_ptr, png_inforp info_ptr,
1348 int transforms, voidp params)
1349{
1350 if (png_ptr == NULL || info_ptr == NULL)
1351 return;
1352
1353 if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
1354 {
1355 png_app_error(png_ptr, "no rows for png_write_image to write");
1356 return;
1357 }
1358
1359 /* Write the file header information. */
1360 png_write_info(png_ptr, info_ptr);
1361
1362 /* ------ these transformations don't touch the info structure ------- */
1363
1364 /* Invert monochrome pixels */
1365 if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
1366#ifdef PNG_WRITE_INVERT_SUPPORTED
1367 png_set_invert_mono(png_ptr);
1368#else
1369 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
1370#endif
1371
1372 /* Shift the pixels up to a legal bit depth and fill in
1373 * as appropriate to correctly scale the image.
1374 */
1375 if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
1376#ifdef PNG_WRITE_SHIFT_SUPPORTED
1377 if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
1378 png_set_shift(png_ptr, &info_ptr->sig_bit);
1379#else
1380 png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
1381#endif
1382
1383 /* Pack pixels into bytes */
1384 if ((transforms & PNG_TRANSFORM_PACKING) != 0)
1385#ifdef PNG_WRITE_PACK_SUPPORTED
1386 png_set_packing(png_ptr);
1387#else
1388 png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
1389#endif
1390
1391 /* Swap location of alpha bytes from ARGB to RGBA */
1392 if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
1393#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1394 png_set_swap_alpha(png_ptr);
1395#else
1396 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
1397#endif
1398
1399 /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
1400 * RGB, note that the code expects the input color type to be G or RGB; no
1401 * alpha channel.
1402 */
1403 if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER|
1404 PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0)
1405 {
1406#ifdef PNG_WRITE_FILLER_SUPPORTED
1407 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0)
1408 {
1409 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
1410 png_app_error(png_ptr,
1411 "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
1412
1413 /* Continue if ignored - this is the pre-1.6.10 behavior */
1414 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1415 }
1416
1417 else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
1418 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1419#else
1420 png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
1421#endif
1422 }
1423
1424 /* Flip BGR pixels to RGB */
1425 if ((transforms & PNG_TRANSFORM_BGR) != 0)
1426#ifdef PNG_WRITE_BGR_SUPPORTED
1427 png_set_bgr(png_ptr);
1428#else
1429 png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
1430#endif
1431
1432 /* Swap bytes of 16-bit files to most significant byte first */
1433 if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
1434#ifdef PNG_WRITE_SWAP_SUPPORTED
1435 png_set_swap(png_ptr);
1436#else
1437 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
1438#endif
1439
1440 /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */
1441 if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
1442#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1443 png_set_packswap(png_ptr);
1444#else
1445 png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
1446#endif
1447
1448 /* Invert the alpha channel from opacity to transparency */
1449 if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
1450#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1451 png_set_invert_alpha(png_ptr);
1452#else
1453 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
1454#endif
1455
1456 /* ----------------------- end of transformations ------------------- */
1457
1458 /* Write the bits */
1459 png_write_image(png_ptr, info_ptr->row_pointers);
1460
1461 /* It is REQUIRED to call this to finish writing the rest of the file */
1462 png_write_end(png_ptr, info_ptr);
1463
1464 PNG_UNUSED(params)
1465}
1466#endif
1467
1468
1469#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
1470/* Initialize the write structure - general purpose utility. */
1471static int
1472png_image_write_init(png_imagep image)
1473{
1474 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
1475 png_safe_error, png_safe_warning);
1476
1477 if (png_ptr != NULL)
1478 {
1479 png_infop info_ptr = png_create_info_struct(png_ptr);
1480
1481 if (info_ptr != NULL)
1482 {
1483 png_controlp control = png_voidcast(png_controlp,
1484 png_malloc_warn(png_ptr, (sizeof *control)));
1485
1486 if (control != NULL)
1487 {
1488 memset(control, 0, (sizeof *control));
1489
1490 control->png_ptr = png_ptr;
1491 control->info_ptr = info_ptr;
1492 control->for_write = 1;
1493
1494 image->opaque = control;
1495 return 1;
1496 }
1497
1498 /* Error clean up */
1499 png_destroy_info_struct(png_ptr, &info_ptr);
1500 }
1501
1502 png_destroy_write_struct(&png_ptr, NULL);
1503 }
1504
1505 return png_image_error(image, "png_image_write_: out of memory");
1506}
1507
1508/* Arguments to png_image_write_main: */
1509typedef struct
1510{
1511 /* Arguments: */
1512 png_imagep image;
1513 png_const_voidp buffer;
1514 png_int_32 row_stride;
1515 png_const_voidp colormap;
1516 int convert_to_8bit;
1517 /* Local variables: */
1518 png_const_voidp first_row;
1519 ptrdiff_t row_bytes;
1520 png_voidp local_row;
1521 /* Byte count for memory writing */
1522 png_bytep memory;
1523 png_alloc_size_t memory_bytes; /* not used for STDIO */
1524 png_alloc_size_t output_bytes; /* running total */
1525} png_image_write_control;
1526
1527/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
1528 * do any necessary byte swapping. The component order is defined by the
1529 * png_image format value.
1530 */
1531static int
1532png_write_image_16bit(png_voidp argument)
1533{
1534 png_image_write_control *display = png_voidcast(png_image_write_control*,
1535 argument);
1536 png_imagep image = display->image;
1537 png_structrp png_ptr = image->opaque->png_ptr;
1538
1539 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
1540 display->first_row);
1541 png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
1542 png_uint_16p row_end;
1543 unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
1544 3 : 1;
1545 int aindex = 0;
1546 png_uint_32 y = image->height;
1547
1548 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
1549 {
1550# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
1551 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
1552 {
1553 aindex = -1;
1554 ++input_row; /* To point to the first component */
1555 ++output_row;
1556 }
1557 else
1558 aindex = (int)channels;
1559# else
1560 aindex = (int)channels;
1561# endif
1562 }
1563
1564 else
1565 png_error(png_ptr, "png_write_image: internal call error");
1566
1567 /* Work out the output row end and count over this, note that the increment
1568 * above to 'row' means that row_end can actually be beyond the end of the
1569 * row; this is correct.
1570 */
1571 row_end = output_row + image->width * (channels+1);
1572
1573 for (; y > 0; --y)
1574 {
1575 png_const_uint_16p in_ptr = input_row;
1576 png_uint_16p out_ptr = output_row;
1577
1578 while (out_ptr < row_end)
1579 {
1580 png_uint_16 alpha = in_ptr[aindex];
1581 png_uint_32 reciprocal = 0;
1582 int c;
1583
1584 out_ptr[aindex] = alpha;
1585
1586 /* Calculate a reciprocal. The correct calculation is simply
1587 * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
1588 * allows correct rounding by adding .5 before the shift. 'reciprocal'
1589 * is only initialized when required.
1590 */
1591 if (alpha > 0 && alpha < 65535)
1592 reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
1593
1594 c = (int)channels;
1595 do /* always at least one channel */
1596 {
1597 png_uint_16 component = *in_ptr++;
1598
1599 /* The following gives 65535 for an alpha of 0, which is fine,
1600 * otherwise if 0/0 is represented as some other value there is more
1601 * likely to be a discontinuity which will probably damage
1602 * compression when moving from a fully transparent area to a
1603 * nearly transparent one. (The assumption here is that opaque
1604 * areas tend not to be 0 intensity.)
1605 */
1606 if (component >= alpha)
1607 component = 65535;
1608
1609 /* component<alpha, so component/alpha is less than one and
1610 * component*reciprocal is less than 2^31.
1611 */
1612 else if (component > 0 && alpha < 65535)
1613 {
1614 png_uint_32 calc = component * reciprocal;
1615 calc += 16384; /* round to nearest */
1616 component = (png_uint_16)(calc >> 15);
1617 }
1618
1619 *out_ptr++ = component;
1620 }
1621 while (--c > 0);
1622
1623 /* Skip to next component (skip the intervening alpha channel) */
1624 ++in_ptr;
1625 ++out_ptr;
1626 }
1627
1628 png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
1629 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
1630 }
1631
1632 return 1;
1633}
1634
1635/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
1636 * is present it must be removed from the components, the components are then
1637 * written in sRGB encoding. No components are added or removed.
1638 *
1639 * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
1640 * calculation can be done to 15 bits of accuracy; however, the output needs to
1641 * be scaled in the range 0..255*65535, so include that scaling here.
1642 */
1643# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+((alpha)>>1))/(alpha))
1644
1645static png_byte
1646png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
1647 png_uint_32 reciprocal/*from the above macro*/)
1648{
1649 /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
1650 * is represented as some other value there is more likely to be a
1651 * discontinuity which will probably damage compression when moving from a
1652 * fully transparent area to a nearly transparent one. (The assumption here
1653 * is that opaque areas tend not to be 0 intensity.)
1654 *
1655 * There is a rounding problem here; if alpha is less than 128 it will end up
1656 * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
1657 * output change for this too.
1658 */
1659 if (component >= alpha || alpha < 128)
1660 return 255;
1661
1662 /* component<alpha, so component/alpha is less than one and
1663 * component*reciprocal is less than 2^31.
1664 */
1665 else if (component > 0)
1666 {
1667 /* The test is that alpha/257 (rounded) is less than 255, the first value
1668 * that becomes 255 is 65407.
1669 * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
1670 * be exact!) [Could also test reciprocal != 0]
1671 */
1672 if (alpha < 65407)
1673 {
1674 component *= reciprocal;
1675 component += 64; /* round to nearest */
1676 component >>= 7;
1677 }
1678
1679 else
1680 component *= 255;
1681
1682 /* Convert the component to sRGB. */
1683 return (png_byte)PNG_sRGB_FROM_LINEAR(component);
1684 }
1685
1686 else
1687 return 0;
1688}
1689
1690static int
1691png_write_image_8bit(png_voidp argument)
1692{
1693 png_image_write_control *display = png_voidcast(png_image_write_control*,
1694 argument);
1695 png_imagep image = display->image;
1696 png_structrp png_ptr = image->opaque->png_ptr;
1697
1698 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
1699 display->first_row);
1700 png_bytep output_row = png_voidcast(png_bytep, display->local_row);
1701 png_uint_32 y = image->height;
1702 unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
1703 3 : 1;
1704
1705 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
1706 {
1707 png_bytep row_end;
1708 int aindex;
1709
1710# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
1711 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
1712 {
1713 aindex = -1;
1714 ++input_row; /* To point to the first component */
1715 ++output_row;
1716 }
1717
1718 else
1719# endif
1720 aindex = (int)channels;
1721
1722 /* Use row_end in place of a loop counter: */
1723 row_end = output_row + image->width * (channels+1);
1724
1725 for (; y > 0; --y)
1726 {
1727 png_const_uint_16p in_ptr = input_row;
1728 png_bytep out_ptr = output_row;
1729
1730 while (out_ptr < row_end)
1731 {
1732 png_uint_16 alpha = in_ptr[aindex];
1733 png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
1734 png_uint_32 reciprocal = 0;
1735 int c;
1736
1737 /* Scale and write the alpha channel. */
1738 out_ptr[aindex] = alphabyte;
1739
1740 if (alphabyte > 0 && alphabyte < 255)
1741 reciprocal = UNP_RECIPROCAL(alpha);
1742
1743 c = (int)channels;
1744 do /* always at least one channel */
1745 *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
1746 while (--c > 0);
1747
1748 /* Skip to next component (skip the intervening alpha channel) */
1749 ++in_ptr;
1750 ++out_ptr;
1751 } /* while out_ptr < row_end */
1752
1753 png_write_row(png_ptr, png_voidcast(png_const_bytep,
1754 display->local_row));
1755 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
1756 } /* while y */
1757 }
1758
1759 else
1760 {
1761 /* No alpha channel, so the row_end really is the end of the row and it
1762 * is sufficient to loop over the components one by one.
1763 */
1764 png_bytep row_end = output_row + image->width * channels;
1765
1766 for (; y > 0; --y)
1767 {
1768 png_const_uint_16p in_ptr = input_row;
1769 png_bytep out_ptr = output_row;
1770
1771 while (out_ptr < row_end)
1772 {
1773 png_uint_32 component = *in_ptr++;
1774
1775 component *= 255;
1776 *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
1777 }
1778
1779 png_write_row(png_ptr, output_row);
1780 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
1781 }
1782 }
1783
1784 return 1;
1785}
1786
1787static void
1788png_image_set_PLTE(png_image_write_control *display)
1789{
1790 png_imagep image = display->image;
1791 const void *cmap = display->colormap;
1792 int entries = image->colormap_entries > 256 ? 256 :
1793 (int)image->colormap_entries;
1794
1795 /* NOTE: the caller must check for cmap != NULL and entries != 0 */
1796 png_uint_32 format = image->format;
1797 unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
1798
1799# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
1800 defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
1801 int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
1802 (format & PNG_FORMAT_FLAG_ALPHA) != 0;
1803# else
1804# define afirst 0
1805# endif
1806
1807# ifdef PNG_FORMAT_BGR_SUPPORTED
1808 int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
1809# else
1810# define bgr 0
1811# endif
1812
1813 int i, num_trans;
1814 png_color palette[256];
1815 png_byte tRNS[256];
1816
1817 memset(tRNS, 255, (sizeof tRNS));
1818 memset(palette, 0, (sizeof palette));
1819
1820 for (i=num_trans=0; i<entries; ++i)
1821 {
1822 /* This gets automatically converted to sRGB with reversal of the
1823 * pre-multiplication if the color-map has an alpha channel.
1824 */
1825 if ((format & PNG_FORMAT_FLAG_LINEAR) != 0)
1826 {
1827 png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
1828
1829 entry += (unsigned int)i * channels;
1830
1831 if ((channels & 1) != 0) /* no alpha */
1832 {
1833 if (channels >= 3) /* RGB */
1834 {
1835 palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
1836 entry[(2 ^ bgr)]);
1837 palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
1838 entry[1]);
1839 palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
1840 entry[bgr]);
1841 }
1842
1843 else /* Gray */
1844 palette[i].blue = palette[i].red = palette[i].green =
1845 (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
1846 }
1847
1848 else /* alpha */
1849 {
1850 png_uint_16 alpha = entry[afirst ? 0 : channels-1];
1851 png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
1852 png_uint_32 reciprocal = 0;
1853
1854 /* Calculate a reciprocal, as in the png_write_image_8bit code above
1855 * this is designed to produce a value scaled to 255*65535 when
1856 * divided by 128 (i.e. asr 7).
1857 */
1858 if (alphabyte > 0 && alphabyte < 255)
1859 reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
1860
1861 tRNS[i] = alphabyte;
1862 if (alphabyte < 255)
1863 num_trans = i+1;
1864
1865 if (channels >= 3) /* RGB */
1866 {
1867 palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
1868 alpha, reciprocal);
1869 palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
1870 reciprocal);
1871 palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
1872 reciprocal);
1873 }
1874
1875 else /* gray */
1876 palette[i].blue = palette[i].red = palette[i].green =
1877 png_unpremultiply(entry[afirst], alpha, reciprocal);
1878 }
1879 }
1880
1881 else /* Color-map has sRGB values */
1882 {
1883 png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
1884
1885 entry += (unsigned int)i * channels;
1886
1887 switch (channels)
1888 {
1889 case 4:
1890 tRNS[i] = entry[afirst ? 0 : 3];
1891 if (tRNS[i] < 255)
1892 num_trans = i+1;
1893 /* FALLTHROUGH */
1894 case 3:
1895 palette[i].blue = entry[afirst + (2 ^ bgr)];
1896 palette[i].green = entry[afirst + 1];
1897 palette[i].red = entry[afirst + bgr];
1898 break;
1899
1900 case 2:
1901 tRNS[i] = entry[1 ^ afirst];
1902 if (tRNS[i] < 255)
1903 num_trans = i+1;
1904 /* FALLTHROUGH */
1905 case 1:
1906 palette[i].blue = palette[i].red = palette[i].green =
1907 entry[afirst];
1908 break;
1909
1910 default:
1911 break;
1912 }
1913 }
1914 }
1915
1916# ifdef afirst
1917# undef afirst
1918# endif
1919# ifdef bgr
1920# undef bgr
1921# endif
1922
1923 png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
1924 entries);
1925
1926 if (num_trans > 0)
1927 png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
1928 num_trans, NULL);
1929
1930 image->colormap_entries = (png_uint_32)entries;
1931}
1932
1933static int
1934png_image_write_main(png_voidp argument)
1935{
1936 png_image_write_control *display = png_voidcast(png_image_write_control*,
1937 argument);
1938 png_imagep image = display->image;
1939 png_structrp png_ptr = image->opaque->png_ptr;
1940 png_inforp info_ptr = image->opaque->info_ptr;
1941 png_uint_32 format = image->format;
1942
1943 /* The following four ints are actually booleans */
1944 int colormap = (format & PNG_FORMAT_FLAG_COLORMAP);
1945 int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */
1946 int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA);
1947 int write_16bit = linear && (display->convert_to_8bit == 0);
1948
1949# ifdef PNG_BENIGN_ERRORS_SUPPORTED
1950 /* Make sure we error out on any bad situation */
1951 png_set_benign_errors(png_ptr, 0/*error*/);
1952# endif
1953
1954 /* Default the 'row_stride' parameter if required, also check the row stride
1955 * and total image size to ensure that they are within the system limits.
1956 */
1957 {
1958 unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
1959
1960 if (image->width <= 0x7fffffffU/channels) /* no overflow */
1961 {
1962 png_uint_32 check;
1963 png_uint_32 png_row_stride = image->width * channels;
1964
1965 if (display->row_stride == 0)
1966 display->row_stride = (png_int_32)/*SAFE*/png_row_stride;
1967
1968 if (display->row_stride < 0)
1969 check = (png_uint_32)(-display->row_stride);
1970
1971 else
1972 check = (png_uint_32)display->row_stride;
1973
1974 if (check >= png_row_stride)
1975 {
1976 /* Now check for overflow of the image buffer calculation; this
1977 * limits the whole image size to 32 bits for API compatibility with
1978 * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
1979 */
1980 if (image->height > 0xffffffffU/png_row_stride)
1981 png_error(image->opaque->png_ptr, "memory image too large");
1982 }
1983
1984 else
1985 png_error(image->opaque->png_ptr, "supplied row stride too small");
1986 }
1987
1988 else
1989 png_error(image->opaque->png_ptr, "image row stride too large");
1990 }
1991
1992 /* Set the required transforms then write the rows in the correct order. */
1993 if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0)
1994 {
1995 if (display->colormap != NULL && image->colormap_entries > 0)
1996 {
1997 png_uint_32 entries = image->colormap_entries;
1998
1999 png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
2000 entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
2001 PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
2002 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
2003
2004 png_image_set_PLTE(display);
2005 }
2006
2007 else
2008 png_error(image->opaque->png_ptr,
2009 "no color-map for color-mapped image");
2010 }
2011
2012 else
2013 png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
2014 write_16bit ? 16 : 8,
2015 ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
2016 ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
2017 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
2018
2019 /* Counter-intuitively the data transformations must be called *after*
2020 * png_write_info, not before as in the read code, but the 'set' functions
2021 * must still be called before. Just set the color space information, never
2022 * write an interlaced image.
2023 */
2024
2025 if (write_16bit != 0)
2026 {
2027 /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
2028 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
2029
2030 if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
2031 png_set_cHRM_fixed(png_ptr, info_ptr,
2032 /* color x y */
2033 /* white */ 31270, 32900,
2034 /* red */ 64000, 33000,
2035 /* green */ 30000, 60000,
2036 /* blue */ 15000, 6000
2037 );
2038 }
2039
2040 else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
2041 png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
2042
2043 /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
2044 * space must still be gamma encoded.
2045 */
2046 else
2047 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
2048
2049 /* Write the file header. */
2050 png_write_info(png_ptr, info_ptr);
2051
2052 /* Now set up the data transformations (*after* the header is written),
2053 * remove the handled transformations from the 'format' flags for checking.
2054 *
2055 * First check for a little endian system if writing 16-bit files.
2056 */
2057 if (write_16bit != 0)
2058 {
2059 png_uint_16 le = 0x0001;
2060
2061 if ((*(png_const_bytep) & le) != 0)
2062 png_set_swap(png_ptr);
2063 }
2064
2065# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
2066 if ((format & PNG_FORMAT_FLAG_BGR) != 0)
2067 {
2068 if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0)
2069 png_set_bgr(png_ptr);
2070 format &= ~PNG_FORMAT_FLAG_BGR;
2071 }
2072# endif
2073
2074# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
2075 if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
2076 {
2077 if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
2078 png_set_swap_alpha(png_ptr);
2079 format &= ~PNG_FORMAT_FLAG_AFIRST;
2080 }
2081# endif
2082
2083 /* If there are 16 or fewer color-map entries we wrote a lower bit depth
2084 * above, but the application data is still byte packed.
2085 */
2086 if (colormap != 0 && image->colormap_entries <= 16)
2087 png_set_packing(png_ptr);
2088
2089 /* That should have handled all (both) the transforms. */
2090 if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
2091 PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
2092 png_error(png_ptr, "png_write_image: unsupported transformation");
2093
2094 {
2095 png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
2096 ptrdiff_t row_bytes = display->row_stride;
2097
2098 if (linear != 0)
2099 row_bytes *= (sizeof (png_uint_16));
2100
2101 if (row_bytes < 0)
2102 row += (image->height-1) * (-row_bytes);
2103
2104 display->first_row = row;
2105 display->row_bytes = row_bytes;
2106 }
2107
2108 /* Apply 'fast' options if the flag is set. */
2109 if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
2110 {
2111 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
2112 /* NOTE: determined by experiment using pngstest, this reflects some
2113 * balance between the time to write the image once and the time to read
2114 * it about 50 times. The speed-up in pngstest was about 10-20% of the
2115 * total (user) time on a heavily loaded system.
2116 */
2117# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
2118 png_set_compression_level(png_ptr, 3);
2119# endif
2120 }
2121
2122 /* Check for the cases that currently require a pre-transform on the row
2123 * before it is written. This only applies when the input is 16-bit and
2124 * either there is an alpha channel or it is converted to 8-bit.
2125 */
2126 if ((linear != 0 && alpha != 0 ) ||
2127 (colormap == 0 && display->convert_to_8bit != 0))
2128 {
2129 png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
2130 png_get_rowbytes(png_ptr, info_ptr)));
2131 int result;
2132
2133 display->local_row = row;
2134 if (write_16bit != 0)
2135 result = png_safe_execute(image, png_write_image_16bit, display);
2136 else
2137 result = png_safe_execute(image, png_write_image_8bit, display);
2138 display->local_row = NULL;
2139
2140 png_free(png_ptr, row);
2141
2142 /* Skip the 'write_end' on error: */
2143 if (result == 0)
2144 return 0;
2145 }
2146
2147 /* Otherwise this is the case where the input is in a format currently
2148 * supported by the rest of the libpng write code; call it directly.
2149 */
2150 else
2151 {
2152 png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
2153 ptrdiff_t row_bytes = display->row_bytes;
2154 png_uint_32 y = image->height;
2155
2156 for (; y > 0; --y)
2157 {
2158 png_write_row(png_ptr, row);
2159 row += row_bytes;
2160 }
2161 }
2162
2163 png_write_end(png_ptr, info_ptr);
2164 return 1;
2165}
2166
2167
2168static void (PNGCBAPI
2169image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, size_t size)
2170{
2171 png_image_write_control *display = png_voidcast(png_image_write_control*,
2172 png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/);
2173 png_alloc_size_t ob = display->output_bytes;
2174
2175 /* Check for overflow; this should never happen: */
2176 if (size <= ((png_alloc_size_t)-1) - ob)
2177 {
2178 /* I don't think libpng ever does this, but just in case: */
2179 if (size > 0)
2180 {
2181 if (display->memory_bytes >= ob+size) /* writing */
2182 memcpy(display->memory+ob, data, size);
2183
2184 /* Always update the size: */
2185 display->output_bytes = ob+size;
2186 }
2187 }
2188
2189 else
2190 png_error(png_ptr, "png_image_write_to_memory: PNG too big");
2191}
2192
2193static void (PNGCBAPI
2194image_memory_flush)(png_structp png_ptr)
2195{
2196 PNG_UNUSED(png_ptr)
2197}
2198
2199static int
2200png_image_write_memory(png_voidp argument)
2201{
2202 png_image_write_control *display = png_voidcast(png_image_write_control*,
2203 argument);
2204
2205 /* The rest of the memory-specific init and write_main in an error protected
2206 * environment. This case needs to use callbacks for the write operations
2207 * since libpng has no built in support for writing to memory.
2208 */
2209 png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/,
2210 image_memory_write, image_memory_flush);
2211
2212 return png_image_write_main(display);
2213}
2214
2215int PNGAPI
2216png_image_write_to_memory(png_imagep image, void *memory,
2217 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit,
2218 const void *buffer, png_int_32 row_stride, const void *colormap)
2219{
2220 /* Write the image to the given buffer, or count the bytes if it is NULL */
2221 if (image != NULL && image->version == PNG_IMAGE_VERSION)
2222 {
2223 if (memory_bytes != NULL && buffer != NULL)
2224 {
2225 /* This is to give the caller an easier error detection in the NULL
2226 * case and guard against uninitialized variable problems:
2227 */
2228 if (memory == NULL)
2229 *memory_bytes = 0;
2230
2231 if (png_image_write_init(image) != 0)
2232 {
2233 png_image_write_control display;
2234 int result;
2235
2236 memset(&display, 0, (sizeof display));
2237 display.image = image;
2238 display.buffer = buffer;
2239 display.row_stride = row_stride;
2240 display.colormap = colormap;
2241 display.convert_to_8bit = convert_to_8bit;
2242 display.memory = png_voidcast(png_bytep, memory);
2243 display.memory_bytes = *memory_bytes;
2244 display.output_bytes = 0;
2245
2246 result = png_safe_execute(image, png_image_write_memory, &display);
2247 png_image_free(image);
2248
2249 /* write_memory returns true even if we ran out of buffer. */
2250 if (result)
2251 {
2252 /* On out-of-buffer this function returns '0' but still updates
2253 * memory_bytes:
2254 */
2255 if (memory != NULL && display.output_bytes > *memory_bytes)
2256 result = 0;
2257
2258 *memory_bytes = display.output_bytes;
2259 }
2260
2261 return result;
2262 }
2263
2264 else
2265 return 0;
2266 }
2267
2268 else
2269 return png_image_error(image,
2270 "png_image_write_to_memory: invalid argument");
2271 }
2272
2273 else if (image != NULL)
2274 return png_image_error(image,
2275 "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION");
2276
2277 else
2278 return 0;
2279}
2280
2281#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
2282int PNGAPI
2283png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
2284 const void *buffer, png_int_32 row_stride, const void *colormap)
2285{
2286 /* Write the image to the given (FILE*). */
2287 if (image != NULL && image->version == PNG_IMAGE_VERSION)
2288 {
2289 if (file != NULL && buffer != NULL)
2290 {
2291 if (png_image_write_init(image) != 0)
2292 {
2293 png_image_write_control display;
2294 int result;
2295
2296 /* This is slightly evil, but png_init_io doesn't do anything other
2297 * than this and we haven't changed the standard IO functions so
2298 * this saves a 'safe' function.
2299 */
2300 image->opaque->png_ptr->io_ptr = file;
2301
2302 memset(&display, 0, (sizeof display));
2303 display.image = image;
2304 display.buffer = buffer;
2305 display.row_stride = row_stride;
2306 display.colormap = colormap;
2307 display.convert_to_8bit = convert_to_8bit;
2308
2309 result = png_safe_execute(image, png_image_write_main, &display);
2310 png_image_free(image);
2311 return result;
2312 }
2313
2314 else
2315 return 0;
2316 }
2317
2318 else
2319 return png_image_error(image,
2320 "png_image_write_to_stdio: invalid argument");
2321 }
2322
2323 else if (image != NULL)
2324 return png_image_error(image,
2325 "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
2326
2327 else
2328 return 0;
2329}
2330
2331int PNGAPI
2332png_image_write_to_file(png_imagep image, const char *file_name,
2333 int convert_to_8bit, const void *buffer, png_int_32 row_stride,
2334 const void *colormap)
2335{
2336 /* Write the image to the named file. */
2337 if (image != NULL && image->version == PNG_IMAGE_VERSION)
2338 {
2339 if (file_name != NULL && buffer != NULL)
2340 {
2341 FILE *fp = fopen(file_name, "wb");
2342
2343 if (fp != NULL)
2344 {
2345 if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
2346 row_stride, colormap) != 0)
2347 {
2348 int error; /* from fflush/fclose */
2349
2350 /* Make sure the file is flushed correctly. */
2351 if (fflush(fp) == 0 && ferror(fp) == 0)
2352 {
2353 if (fclose(fp) == 0)
2354 return 1;
2355
2356 error = errno; /* from fclose */
2357 }
2358
2359 else
2360 {
2361 error = errno; /* from fflush or ferror */
2362 (void)fclose(fp);
2363 }
2364
2365 (void)remove(file_name);
2366 /* The image has already been cleaned up; this is just used to
2367 * set the error (because the original write succeeded).
2368 */
2369 return png_image_error(image, strerror(error));
2370 }
2371
2372 else
2373 {
2374 /* Clean up: just the opened file. */
2375 (void)fclose(fp);
2376 (void)remove(file_name);
2377 return 0;
2378 }
2379 }
2380
2381 else
2382 return png_image_error(image, strerror(errno));
2383 }
2384
2385 else
2386 return png_image_error(image,
2387 "png_image_write_to_file: invalid argument");
2388 }
2389
2390 else if (image != NULL)
2391 return png_image_error(image,
2392 "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
2393
2394 else
2395 return 0;
2396}
2397#endif /* SIMPLIFIED_WRITE_STDIO */
2398#endif /* SIMPLIFIED_WRITE */
2399#endif /* WRITE */
Note: See TracBrowser for help on using the repository browser.

© 2024 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette