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source: vbox/trunk/src/libs/libpng-1.2.53/pngwrite.c@ 58639

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libpng 1.2.53 export fix
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1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.2.53 [February 26, 2015]
5 * Copyright (c) 1998-2015 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 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/* Get internal access to png.h */
15#define PNG_INTERNAL
16#define PNG_NO_PEDANTIC_WARNINGS
17#include "png.h"
18#ifdef PNG_WRITE_SUPPORTED
19
20/* Writes all the PNG information. This is the suggested way to use the
21 * library. If you have a new chunk to add, make a function to write it,
22 * and put it in the correct location here. If you want the chunk written
23 * after the image data, put it in png_write_end(). I strongly encourage
24 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
25 * the chunk, as that will keep the code from breaking if you want to just
26 * write a plain PNG file. If you have long comments, I suggest writing
27 * them in png_write_end(), and compressing them.
28 */
29void PNGAPI
30png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
31{
32 png_debug(1, "in png_write_info_before_PLTE");
33
34 if (png_ptr == NULL || info_ptr == NULL)
35 return;
36 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
37 {
38 /* Write PNG signature */
39 png_write_sig(png_ptr);
40#ifdef PNG_MNG_FEATURES_SUPPORTED
41 if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
42 (png_ptr->mng_features_permitted))
43 {
44 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
45 png_ptr->mng_features_permitted = 0;
46 }
47#endif
48 /* Write IHDR information. */
49 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
50 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
51 info_ptr->filter_type,
52#ifdef PNG_WRITE_INTERLACING_SUPPORTED
53 info_ptr->interlace_type);
54#else
55 0);
56#endif
57 /* The rest of these check to see if the valid field has the appropriate
58 * flag set, and if it does, writes the chunk.
59 */
60#ifdef PNG_WRITE_gAMA_SUPPORTED
61 if (info_ptr->valid & PNG_INFO_gAMA)
62 {
63# ifdef PNG_FLOATING_POINT_SUPPORTED
64 png_write_gAMA(png_ptr, info_ptr->gamma);
65#else
66#ifdef PNG_FIXED_POINT_SUPPORTED
67 png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
68# endif
69#endif
70 }
71#endif
72#ifdef PNG_WRITE_sRGB_SUPPORTED
73 if (info_ptr->valid & PNG_INFO_sRGB)
74 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
75#endif
76#ifdef PNG_WRITE_iCCP_SUPPORTED
77 if (info_ptr->valid & PNG_INFO_iCCP)
78 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
79 info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
80#endif
81#ifdef PNG_WRITE_sBIT_SUPPORTED
82 if (info_ptr->valid & PNG_INFO_sBIT)
83 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
84#endif
85#ifdef PNG_WRITE_cHRM_SUPPORTED
86 if (info_ptr->valid & PNG_INFO_cHRM)
87 {
88#ifdef PNG_FLOATING_POINT_SUPPORTED
89 png_write_cHRM(png_ptr,
90 info_ptr->x_white, info_ptr->y_white,
91 info_ptr->x_red, info_ptr->y_red,
92 info_ptr->x_green, info_ptr->y_green,
93 info_ptr->x_blue, info_ptr->y_blue);
94#else
95# ifdef PNG_FIXED_POINT_SUPPORTED
96 png_write_cHRM_fixed(png_ptr,
97 info_ptr->int_x_white, info_ptr->int_y_white,
98 info_ptr->int_x_red, info_ptr->int_y_red,
99 info_ptr->int_x_green, info_ptr->int_y_green,
100 info_ptr->int_x_blue, info_ptr->int_y_blue);
101# endif
102#endif
103 }
104#endif
105#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
106 if (info_ptr->unknown_chunks_num)
107 {
108 png_unknown_chunk *up;
109
110 png_debug(5, "writing extra chunks");
111
112 for (up = info_ptr->unknown_chunks;
113 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
114 up++)
115 {
116 int keep = png_handle_as_unknown(png_ptr, up->name);
117 if (keep != PNG_HANDLE_CHUNK_NEVER &&
118 up->location && !(up->location & PNG_HAVE_PLTE) &&
119 !(up->location & PNG_HAVE_IDAT) &&
120 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
121 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
122 {
123 if (up->size == 0)
124 png_warning(png_ptr, "Writing zero-length unknown chunk");
125 png_write_chunk(png_ptr, up->name, up->data, up->size);
126 }
127 }
128 }
129#endif
130 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
131 }
132}
133
134void PNGAPI
135png_write_info(png_structp png_ptr, png_infop info_ptr)
136{
137#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
138 int i;
139#endif
140
141 png_debug(1, "in png_write_info");
142
143 if (png_ptr == NULL || info_ptr == NULL)
144 return;
145
146 png_write_info_before_PLTE(png_ptr, info_ptr);
147
148 if (info_ptr->valid & PNG_INFO_PLTE)
149 png_write_PLTE(png_ptr, info_ptr->palette,
150 (png_uint_32)info_ptr->num_palette);
151 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
152 png_error(png_ptr, "Valid palette required for paletted images");
153
154#ifdef PNG_WRITE_tRNS_SUPPORTED
155 if (info_ptr->valid & PNG_INFO_tRNS)
156 {
157#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
158 /* Invert the alpha channel (in tRNS) */
159 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
160 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
161 {
162 int j;
163 for (j = 0; j<(int)info_ptr->num_trans; j++)
164 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
165 }
166#endif
167 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
168 info_ptr->num_trans, info_ptr->color_type);
169 }
170#endif
171#ifdef PNG_WRITE_bKGD_SUPPORTED
172 if (info_ptr->valid & PNG_INFO_bKGD)
173 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
174#endif
175#ifdef PNG_WRITE_hIST_SUPPORTED
176 if (info_ptr->valid & PNG_INFO_hIST)
177 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
178#endif
179#ifdef PNG_WRITE_oFFs_SUPPORTED
180 if (info_ptr->valid & PNG_INFO_oFFs)
181 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
182 info_ptr->offset_unit_type);
183#endif
184#ifdef PNG_WRITE_pCAL_SUPPORTED
185 if (info_ptr->valid & PNG_INFO_pCAL)
186 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
187 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
188 info_ptr->pcal_units, info_ptr->pcal_params);
189#endif
190
191#ifdef PNG_sCAL_SUPPORTED
192 if (info_ptr->valid & PNG_INFO_sCAL)
193#ifdef PNG_WRITE_sCAL_SUPPORTED
194#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
195 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
196 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
197#else /* !FLOATING_POINT */
198#ifdef PNG_FIXED_POINT_SUPPORTED
199 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
200 info_ptr->scal_s_width, info_ptr->scal_s_height);
201#endif /* FIXED_POINT */
202#endif /* FLOATING_POINT */
203#else /* !WRITE_sCAL */
204 png_warning(png_ptr,
205 "png_write_sCAL not supported; sCAL chunk not written.");
206#endif /* WRITE_sCAL */
207#endif /* sCAL */
208
209#ifdef PNG_WRITE_pHYs_SUPPORTED
210 if (info_ptr->valid & PNG_INFO_pHYs)
211 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
212 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
213#endif /* pHYs */
214
215#ifdef PNG_WRITE_tIME_SUPPORTED
216 if (info_ptr->valid & PNG_INFO_tIME)
217 {
218 png_write_tIME(png_ptr, &(info_ptr->mod_time));
219 png_ptr->mode |= PNG_WROTE_tIME;
220 }
221#endif /* tIME */
222
223#ifdef PNG_WRITE_sPLT_SUPPORTED
224 if (info_ptr->valid & PNG_INFO_sPLT)
225 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
226 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
227#endif /* sPLT */
228
229#ifdef PNG_WRITE_TEXT_SUPPORTED
230 /* Check to see if we need to write text chunks */
231 for (i = 0; i < info_ptr->num_text; i++)
232 {
233 png_debug2(2, "Writing header text chunk %d, type %d", i,
234 info_ptr->text[i].compression);
235 /* An internationalized chunk? */
236 if (info_ptr->text[i].compression > 0)
237 {
238#ifdef PNG_WRITE_iTXt_SUPPORTED
239 /* Write international chunk */
240 png_write_iTXt(png_ptr,
241 info_ptr->text[i].compression,
242 info_ptr->text[i].key,
243 info_ptr->text[i].lang,
244 info_ptr->text[i].lang_key,
245 info_ptr->text[i].text);
246#else
247 png_warning(png_ptr, "Unable to write international text");
248#endif
249 /* Mark this chunk as written */
250 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
251 }
252 /* If we want a compressed text chunk */
253 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
254 {
255#ifdef PNG_WRITE_zTXt_SUPPORTED
256 /* Write compressed chunk */
257 png_write_zTXt(png_ptr, info_ptr->text[i].key,
258 info_ptr->text[i].text, 0,
259 info_ptr->text[i].compression);
260#else
261 png_warning(png_ptr, "Unable to write compressed text");
262#endif
263 /* Mark this chunk as written */
264 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
265 }
266 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
267 {
268#ifdef PNG_WRITE_tEXt_SUPPORTED
269 /* Write uncompressed chunk */
270 png_write_tEXt(png_ptr, info_ptr->text[i].key,
271 info_ptr->text[i].text,
272 0);
273 /* Mark this chunk as written */
274 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
275#else
276 /* Can't get here */
277 png_warning(png_ptr, "Unable to write uncompressed text");
278#endif
279 }
280 }
281#endif /* tEXt */
282
283#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
284 if (info_ptr->unknown_chunks_num)
285 {
286 png_unknown_chunk *up;
287
288 png_debug(5, "writing extra chunks");
289
290 for (up = info_ptr->unknown_chunks;
291 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
292 up++)
293 {
294 int keep = png_handle_as_unknown(png_ptr, up->name);
295 if (keep != PNG_HANDLE_CHUNK_NEVER &&
296 up->location && (up->location & PNG_HAVE_PLTE) &&
297 !(up->location & PNG_HAVE_IDAT) &&
298 !(up->location & PNG_AFTER_IDAT) &&
299 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
300 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
301 {
302 png_write_chunk(png_ptr, up->name, up->data, up->size);
303 }
304 }
305 }
306#endif
307}
308
309/* Writes the end of the PNG file. If you don't want to write comments or
310 * time information, you can pass NULL for info. If you already wrote these
311 * in png_write_info(), do not write them again here. If you have long
312 * comments, I suggest writing them here, and compressing them.
313 */
314void PNGAPI
315png_write_end(png_structp png_ptr, png_infop info_ptr)
316{
317 png_debug(1, "in png_write_end");
318
319 if (png_ptr == NULL)
320 return;
321 if (!(png_ptr->mode & PNG_HAVE_IDAT))
322 png_error(png_ptr, "No IDATs written into file");
323
324 /* See if user wants us to write information chunks */
325 if (info_ptr != NULL)
326 {
327#ifdef PNG_WRITE_TEXT_SUPPORTED
328 int i; /* local index variable */
329#endif
330#ifdef PNG_WRITE_tIME_SUPPORTED
331 /* Check to see if user has supplied a time chunk */
332 if ((info_ptr->valid & PNG_INFO_tIME) &&
333 !(png_ptr->mode & PNG_WROTE_tIME))
334 png_write_tIME(png_ptr, &(info_ptr->mod_time));
335#endif
336#ifdef PNG_WRITE_TEXT_SUPPORTED
337 /* Loop through comment chunks */
338 for (i = 0; i < info_ptr->num_text; i++)
339 {
340 png_debug2(2, "Writing trailer text chunk %d, type %d", i,
341 info_ptr->text[i].compression);
342 /* An internationalized chunk? */
343 if (info_ptr->text[i].compression > 0)
344 {
345#ifdef PNG_WRITE_iTXt_SUPPORTED
346 /* Write international chunk */
347 png_write_iTXt(png_ptr,
348 info_ptr->text[i].compression,
349 info_ptr->text[i].key,
350 info_ptr->text[i].lang,
351 info_ptr->text[i].lang_key,
352 info_ptr->text[i].text);
353#else
354 png_warning(png_ptr, "Unable to write international text");
355#endif
356 /* Mark this chunk as written */
357 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
358 }
359 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
360 {
361#ifdef PNG_WRITE_zTXt_SUPPORTED
362 /* Write compressed chunk */
363 png_write_zTXt(png_ptr, info_ptr->text[i].key,
364 info_ptr->text[i].text, 0,
365 info_ptr->text[i].compression);
366#else
367 png_warning(png_ptr, "Unable to write compressed text");
368#endif
369 /* Mark this chunk as written */
370 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
371 }
372 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
373 {
374#ifdef PNG_WRITE_tEXt_SUPPORTED
375 /* Write uncompressed chunk */
376 png_write_tEXt(png_ptr, info_ptr->text[i].key,
377 info_ptr->text[i].text, 0);
378#else
379 png_warning(png_ptr, "Unable to write uncompressed text");
380#endif
381
382 /* Mark this chunk as written */
383 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
384 }
385 }
386#endif
387#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
388 if (info_ptr->unknown_chunks_num)
389 {
390 png_unknown_chunk *up;
391
392 png_debug(5, "writing extra chunks");
393
394 for (up = info_ptr->unknown_chunks;
395 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
396 up++)
397 {
398 int keep = png_handle_as_unknown(png_ptr, up->name);
399 if (keep != PNG_HANDLE_CHUNK_NEVER &&
400 up->location && (up->location & PNG_AFTER_IDAT) &&
401 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
402 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
403 {
404 png_write_chunk(png_ptr, up->name, up->data, up->size);
405 }
406 }
407 }
408#endif
409 }
410
411 png_ptr->mode |= PNG_AFTER_IDAT;
412
413 /* Write end of PNG file */
414 png_write_IEND(png_ptr);
415 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
416 * and restored again in libpng-1.2.30, may cause some applications that
417 * do not set png_ptr->output_flush_fn to crash. If your application
418 * experiences a problem, please try building libpng with
419 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
420 * png-mng-implement at lists.sf.net .
421 */
422#ifdef PNG_WRITE_FLUSH_SUPPORTED
423# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
424 png_flush(png_ptr);
425# endif
426#endif
427}
428
429#ifdef PNG_CONVERT_tIME_SUPPORTED
430/* "tm" structure is not supported on WindowsCE */
431void PNGAPI
432png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
433{
434 png_debug(1, "in png_convert_from_struct_tm");
435
436 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
437 ptime->month = (png_byte)(ttime->tm_mon + 1);
438 ptime->day = (png_byte)ttime->tm_mday;
439 ptime->hour = (png_byte)ttime->tm_hour;
440 ptime->minute = (png_byte)ttime->tm_min;
441 ptime->second = (png_byte)ttime->tm_sec;
442}
443
444void PNGAPI
445png_convert_from_time_t(png_timep ptime, time_t ttime)
446{
447 struct tm *tbuf;
448
449 png_debug(1, "in png_convert_from_time_t");
450
451 tbuf = gmtime(&ttime);
452 png_convert_from_struct_tm(ptime, tbuf);
453}
454#endif
455
456/* Initialize png_ptr structure, and allocate any memory needed */
457png_structp PNGAPI
458png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
459 png_error_ptr error_fn, png_error_ptr warn_fn)
460{
461#ifdef PNG_USER_MEM_SUPPORTED
462 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
463 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
464}
465
466/* Alternate initialize png_ptr structure, and allocate any memory needed */
467png_structp PNGAPI
468png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
469 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
470 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
471{
472#endif /* PNG_USER_MEM_SUPPORTED */
473#ifdef PNG_SETJMP_SUPPORTED
474 volatile
475#endif
476 png_structp png_ptr;
477#ifdef PNG_SETJMP_SUPPORTED
478#ifdef USE_FAR_KEYWORD
479 jmp_buf jmpbuf;
480#endif
481#endif
482 int i;
483
484 png_debug(1, "in png_create_write_struct");
485
486#ifdef PNG_USER_MEM_SUPPORTED
487 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
488 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
489#else
490 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
491#endif /* PNG_USER_MEM_SUPPORTED */
492 if (png_ptr == NULL)
493 return (NULL);
494
495 /* Added at libpng-1.2.6 */
496#ifdef PNG_SET_USER_LIMITS_SUPPORTED
497 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
498 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
499#endif
500
501#ifdef PNG_SETJMP_SUPPORTED
502#ifdef USE_FAR_KEYWORD
503 if (setjmp(jmpbuf))
504#else
505 if (setjmp(png_ptr->jmpbuf))
506#endif
507 {
508 png_free(png_ptr, png_ptr->zbuf);
509 png_ptr->zbuf = NULL;
510#ifdef PNG_USER_MEM_SUPPORTED
511 png_destroy_struct_2((png_voidp)png_ptr,
512 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
513#else
514 png_destroy_struct((png_voidp)png_ptr);
515#endif
516 return (NULL);
517 }
518#ifdef USE_FAR_KEYWORD
519 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
520#endif
521#endif
522
523#ifdef PNG_USER_MEM_SUPPORTED
524 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
525#endif /* PNG_USER_MEM_SUPPORTED */
526 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
527
528 if (user_png_ver != NULL)
529 {
530 int found_dots = 0;
531 i = -1;
532
533 do
534 {
535 i++;
536 if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
537 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
538 if (user_png_ver[i] == '.')
539 found_dots++;
540 } while (found_dots < 2 && user_png_ver[i] != 0 &&
541 PNG_LIBPNG_VER_STRING[i] != 0);
542 }
543 else
544 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
545
546 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
547 {
548 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
549 * we must recompile any applications that use any older library version.
550 * For versions after libpng 1.0, we will be compatible, so we need
551 * only check the first digit.
552 */
553 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
554 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
555 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
556 {
557#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
558 char msg[80];
559 if (user_png_ver)
560 {
561 png_snprintf(msg, 80,
562 "Application was compiled with png.h from libpng-%.20s",
563 user_png_ver);
564 png_warning(png_ptr, msg);
565 }
566 png_snprintf(msg, 80,
567 "Application is running with png.c from libpng-%.20s",
568 png_libpng_ver);
569 png_warning(png_ptr, msg);
570#endif
571#ifdef PNG_ERROR_NUMBERS_SUPPORTED
572 png_ptr->flags = 0;
573#endif
574 png_error(png_ptr,
575 "Incompatible libpng version in application and library");
576 }
577 }
578
579 /* Initialize zbuf - compression buffer */
580 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
581 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
582 (png_uint_32)png_ptr->zbuf_size);
583
584 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
585 png_flush_ptr_NULL);
586
587#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
588 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
589 1, png_doublep_NULL, png_doublep_NULL);
590#endif
591
592#ifdef PNG_SETJMP_SUPPORTED
593 /* Applications that neglect to set up their own setjmp() and then
594 * encounter a png_error() will longjmp here. Since the jmpbuf is
595 * then meaningless we abort instead of returning.
596 */
597#ifdef USE_FAR_KEYWORD
598 if (setjmp(jmpbuf))
599 PNG_ABORT();
600 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
601#else
602 if (setjmp(png_ptr->jmpbuf))
603 PNG_ABORT();
604#endif
605#endif
606 return (png_ptr);
607}
608
609/* Initialize png_ptr structure, and allocate any memory needed */
610#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
611/* Deprecated. */
612#undef png_write_init
613void PNGAPI
614png_write_init(png_structp png_ptr)
615{
616 /* We only come here via pre-1.0.7-compiled applications */
617 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
618}
619
620void PNGAPI
621png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
622 png_size_t png_struct_size, png_size_t png_info_size)
623{
624 /* We only come here via pre-1.0.12-compiled applications */
625 if (png_ptr == NULL) return;
626#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
627 if (png_sizeof(png_struct) > png_struct_size ||
628 png_sizeof(png_info) > png_info_size)
629 {
630 char msg[80];
631 png_ptr->warning_fn = NULL;
632 if (user_png_ver)
633 {
634 png_snprintf(msg, 80,
635 "Application was compiled with png.h from libpng-%.20s",
636 user_png_ver);
637 png_warning(png_ptr, msg);
638 }
639 png_snprintf(msg, 80,
640 "Application is running with png.c from libpng-%.20s",
641 png_libpng_ver);
642 png_warning(png_ptr, msg);
643 }
644#endif
645 if (png_sizeof(png_struct) > png_struct_size)
646 {
647 png_ptr->error_fn = NULL;
648#ifdef PNG_ERROR_NUMBERS_SUPPORTED
649 png_ptr->flags = 0;
650#endif
651 png_error(png_ptr,
652 "The png struct allocated by the application for writing is"
653 " too small.");
654 }
655 if (png_sizeof(png_info) > png_info_size)
656 {
657 png_ptr->error_fn = NULL;
658#ifdef PNG_ERROR_NUMBERS_SUPPORTED
659 png_ptr->flags = 0;
660#endif
661 png_error(png_ptr,
662 "The info struct allocated by the application for writing is"
663 " too small.");
664 }
665 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
666}
667#endif /* PNG_1_0_X || PNG_1_2_X */
668
669
670void PNGAPI
671png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
672 png_size_t png_struct_size)
673{
674 png_structp png_ptr = *ptr_ptr;
675#ifdef PNG_SETJMP_SUPPORTED
676 jmp_buf tmp_jmp; /* to save current jump buffer */
677#endif
678
679 int i = 0;
680
681 if (png_ptr == NULL)
682 return;
683
684 do
685 {
686 if (user_png_ver[i] != png_libpng_ver[i])
687 {
688#ifdef PNG_LEGACY_SUPPORTED
689 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
690#else
691 png_ptr->warning_fn = NULL;
692 png_warning(png_ptr,
693 "Application uses deprecated png_write_init() and should be recompiled.");
694#endif
695 }
696 i++;
697 } while (png_libpng_ver[i] != 0 && user_png_ver[i] != 0);
698
699 png_debug(1, "in png_write_init_3");
700
701#ifdef PNG_SETJMP_SUPPORTED
702 /* Save jump buffer and error functions */
703 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
704#endif
705
706 if (png_sizeof(png_struct) > png_struct_size)
707 {
708 png_destroy_struct(png_ptr);
709 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
710 *ptr_ptr = png_ptr;
711 }
712
713 /* Reset all variables to 0 */
714 png_memset(png_ptr, 0, png_sizeof(png_struct));
715
716 /* Added at libpng-1.2.6 */
717#ifdef PNG_SET_USER_LIMITS_SUPPORTED
718 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
719 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
720#endif
721
722#ifdef PNG_SETJMP_SUPPORTED
723 /* Restore jump buffer */
724 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
725#endif
726
727 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
728 png_flush_ptr_NULL);
729
730 /* Initialize zbuf - compression buffer */
731 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
732 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
733 (png_uint_32)png_ptr->zbuf_size);
734#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
735 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
736 1, png_doublep_NULL, png_doublep_NULL);
737#endif
738}
739
740/* Write a few rows of image data. If the image is interlaced,
741 * either you will have to write the 7 sub images, or, if you
742 * have called png_set_interlace_handling(), you will have to
743 * "write" the image seven times.
744 */
745void PNGAPI
746png_write_rows(png_structp png_ptr, png_bytepp row,
747 png_uint_32 num_rows)
748{
749 png_uint_32 i; /* row counter */
750 png_bytepp rp; /* row pointer */
751
752 png_debug(1, "in png_write_rows");
753
754 if (png_ptr == NULL)
755 return;
756
757 /* Loop through the rows */
758 for (i = 0, rp = row; i < num_rows; i++, rp++)
759 {
760 png_write_row(png_ptr, *rp);
761 }
762}
763
764/* Write the image. You only need to call this function once, even
765 * if you are writing an interlaced image.
766 */
767void PNGAPI
768png_write_image(png_structp png_ptr, png_bytepp image)
769{
770 png_uint_32 i; /* row index */
771 int pass, num_pass; /* pass variables */
772 png_bytepp rp; /* points to current row */
773
774 if (png_ptr == NULL)
775 return;
776
777 png_debug(1, "in png_write_image");
778
779#ifdef PNG_WRITE_INTERLACING_SUPPORTED
780 /* Initialize interlace handling. If image is not interlaced,
781 * this will set pass to 1
782 */
783 num_pass = png_set_interlace_handling(png_ptr);
784#else
785 num_pass = 1;
786#endif
787 /* Loop through passes */
788 for (pass = 0; pass < num_pass; pass++)
789 {
790 /* Loop through image */
791 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
792 {
793 png_write_row(png_ptr, *rp);
794 }
795 }
796}
797
798/* Called by user to write a row of image data */
799void PNGAPI
800png_write_row(png_structp png_ptr, png_bytep row)
801{
802 if (png_ptr == NULL)
803 return;
804
805 png_debug2(1, "in png_write_row (row %ld, pass %d)",
806 png_ptr->row_number, png_ptr->pass);
807
808 /* Initialize transformations and other stuff if first time */
809 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
810 {
811 /* Make sure we wrote the header info */
812 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
813 png_error(png_ptr,
814 "png_write_info was never called before png_write_row.");
815
816 /* Check for transforms that have been set but were defined out */
817#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
818 if (png_ptr->transformations & PNG_INVERT_MONO)
819 png_warning(png_ptr,
820 "PNG_WRITE_INVERT_SUPPORTED is not defined.");
821#endif
822#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
823 if (png_ptr->transformations & PNG_FILLER)
824 png_warning(png_ptr,
825 "PNG_WRITE_FILLER_SUPPORTED is not defined.");
826#endif
827#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
828 defined(PNG_READ_PACKSWAP_SUPPORTED)
829 if (png_ptr->transformations & PNG_PACKSWAP)
830 png_warning(png_ptr,
831 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
832#endif
833#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
834 if (png_ptr->transformations & PNG_PACK)
835 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
836#endif
837#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
838 if (png_ptr->transformations & PNG_SHIFT)
839 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
840#endif
841#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
842 if (png_ptr->transformations & PNG_BGR)
843 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
844#endif
845#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
846 if (png_ptr->transformations & PNG_SWAP_BYTES)
847 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
848#endif
849
850 png_write_start_row(png_ptr);
851 }
852
853#ifdef PNG_WRITE_INTERLACING_SUPPORTED
854 /* If interlaced and not interested in row, return */
855 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
856 {
857 switch (png_ptr->pass)
858 {
859 case 0:
860 if (png_ptr->row_number & 0x07)
861 {
862 png_write_finish_row(png_ptr);
863 return;
864 }
865 break;
866 case 1:
867 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
868 {
869 png_write_finish_row(png_ptr);
870 return;
871 }
872 break;
873 case 2:
874 if ((png_ptr->row_number & 0x07) != 4)
875 {
876 png_write_finish_row(png_ptr);
877 return;
878 }
879 break;
880 case 3:
881 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
882 {
883 png_write_finish_row(png_ptr);
884 return;
885 }
886 break;
887 case 4:
888 if ((png_ptr->row_number & 0x03) != 2)
889 {
890 png_write_finish_row(png_ptr);
891 return;
892 }
893 break;
894 case 5:
895 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
896 {
897 png_write_finish_row(png_ptr);
898 return;
899 }
900 break;
901 case 6:
902 if (!(png_ptr->row_number & 0x01))
903 {
904 png_write_finish_row(png_ptr);
905 return;
906 }
907 break;
908 }
909 }
910#endif
911
912 /* Set up row info for transformations */
913 png_ptr->row_info.color_type = png_ptr->color_type;
914 png_ptr->row_info.width = png_ptr->usr_width;
915 png_ptr->row_info.channels = png_ptr->usr_channels;
916 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
917 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
918 png_ptr->row_info.channels);
919
920 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
921 png_ptr->row_info.width);
922
923 png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
924 png_debug1(3, "row_info->width = %lu", png_ptr->row_info.width);
925 png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
926 png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
927 png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
928 png_debug1(3, "row_info->rowbytes = %lu", png_ptr->row_info.rowbytes);
929
930 /* Copy user's row into buffer, leaving room for filter byte. */
931 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
932 png_ptr->row_info.rowbytes);
933
934#ifdef PNG_WRITE_INTERLACING_SUPPORTED
935 /* Handle interlacing */
936 if (png_ptr->interlaced && png_ptr->pass < 6 &&
937 (png_ptr->transformations & PNG_INTERLACE))
938 {
939 png_do_write_interlace(&(png_ptr->row_info),
940 png_ptr->row_buf + 1, png_ptr->pass);
941 /* This should always get caught above, but still ... */
942 if (!(png_ptr->row_info.width))
943 {
944 png_write_finish_row(png_ptr);
945 return;
946 }
947 }
948#endif
949
950 /* Handle other transformations */
951 if (png_ptr->transformations)
952 png_do_write_transformations(png_ptr);
953
954#ifdef PNG_MNG_FEATURES_SUPPORTED
955 /* Write filter_method 64 (intrapixel differencing) only if
956 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
957 * 2. Libpng did not write a PNG signature (this filter_method is only
958 * used in PNG datastreams that are embedded in MNG datastreams) and
959 * 3. The application called png_permit_mng_features with a mask that
960 * included PNG_FLAG_MNG_FILTER_64 and
961 * 4. The filter_method is 64 and
962 * 5. The color_type is RGB or RGBA
963 */
964 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
965 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
966 {
967 /* Intrapixel differencing */
968 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
969 }
970#endif
971
972 /* Find a filter if necessary, filter the row and write it out. */
973 png_write_find_filter(png_ptr, &(png_ptr->row_info));
974
975 if (png_ptr->write_row_fn != NULL)
976 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
977}
978
979#ifdef PNG_WRITE_FLUSH_SUPPORTED
980/* Set the automatic flush interval or 0 to turn flushing off */
981void PNGAPI
982png_set_flush(png_structp png_ptr, int nrows)
983{
984 png_debug(1, "in png_set_flush");
985
986 if (png_ptr == NULL)
987 return;
988 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
989}
990
991/* Flush the current output buffers now */
992void PNGAPI
993png_write_flush(png_structp png_ptr)
994{
995 int wrote_IDAT;
996
997 png_debug(1, "in png_write_flush");
998
999 if (png_ptr == NULL)
1000 return;
1001 /* We have already written out all of the data */
1002 if (png_ptr->row_number >= png_ptr->num_rows)
1003 return;
1004
1005 do
1006 {
1007 int ret;
1008
1009 /* Compress the data */
1010 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
1011 wrote_IDAT = 0;
1012
1013 /* Check for compression errors */
1014 if (ret != Z_OK)
1015 {
1016 if (png_ptr->zstream.msg != NULL)
1017 png_error(png_ptr, png_ptr->zstream.msg);
1018 else
1019 png_error(png_ptr, "zlib error");
1020 }
1021
1022 if (!(png_ptr->zstream.avail_out))
1023 {
1024 /* Write the IDAT and reset the zlib output buffer */
1025 png_write_IDAT(png_ptr, png_ptr->zbuf,
1026 png_ptr->zbuf_size);
1027 png_ptr->zstream.next_out = png_ptr->zbuf;
1028 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1029 wrote_IDAT = 1;
1030 }
1031 } while(wrote_IDAT == 1);
1032
1033 /* If there is any data left to be output, write it into a new IDAT */
1034 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
1035 {
1036 /* Write the IDAT and reset the zlib output buffer */
1037 png_write_IDAT(png_ptr, png_ptr->zbuf,
1038 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1039 png_ptr->zstream.next_out = png_ptr->zbuf;
1040 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1041 }
1042 png_ptr->flush_rows = 0;
1043 png_flush(png_ptr);
1044}
1045#endif /* PNG_WRITE_FLUSH_SUPPORTED */
1046
1047/* Free all memory used by the write */
1048void PNGAPI
1049png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1050{
1051 png_structp png_ptr = NULL;
1052 png_infop info_ptr = NULL;
1053#ifdef PNG_USER_MEM_SUPPORTED
1054 png_free_ptr free_fn = NULL;
1055 png_voidp mem_ptr = NULL;
1056#endif
1057
1058 png_debug(1, "in png_destroy_write_struct");
1059
1060 if (png_ptr_ptr != NULL)
1061 {
1062 png_ptr = *png_ptr_ptr;
1063#ifdef PNG_USER_MEM_SUPPORTED
1064 free_fn = png_ptr->free_fn;
1065 mem_ptr = png_ptr->mem_ptr;
1066#endif
1067 }
1068
1069#ifdef PNG_USER_MEM_SUPPORTED
1070 if (png_ptr != NULL)
1071 {
1072 free_fn = png_ptr->free_fn;
1073 mem_ptr = png_ptr->mem_ptr;
1074 }
1075#endif
1076
1077 if (info_ptr_ptr != NULL)
1078 info_ptr = *info_ptr_ptr;
1079
1080 if (info_ptr != NULL)
1081 {
1082 if (png_ptr != NULL)
1083 {
1084 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1085
1086#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1087 if (png_ptr->num_chunk_list)
1088 {
1089 png_free(png_ptr, png_ptr->chunk_list);
1090 png_ptr->chunk_list = NULL;
1091 png_ptr->num_chunk_list = 0;
1092 }
1093#endif
1094 }
1095
1096#ifdef PNG_USER_MEM_SUPPORTED
1097 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1098 (png_voidp)mem_ptr);
1099#else
1100 png_destroy_struct((png_voidp)info_ptr);
1101#endif
1102 *info_ptr_ptr = NULL;
1103 }
1104
1105 if (png_ptr != NULL)
1106 {
1107 png_write_destroy(png_ptr);
1108#ifdef PNG_USER_MEM_SUPPORTED
1109 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1110 (png_voidp)mem_ptr);
1111#else
1112 png_destroy_struct((png_voidp)png_ptr);
1113#endif
1114 *png_ptr_ptr = NULL;
1115 }
1116}
1117
1118
1119/* Free any memory used in png_ptr struct (old method) */
1120void /* PRIVATE */
1121png_write_destroy(png_structp png_ptr)
1122{
1123#ifdef PNG_SETJMP_SUPPORTED
1124 jmp_buf tmp_jmp; /* Save jump buffer */
1125#endif
1126 png_error_ptr error_fn;
1127 png_error_ptr warning_fn;
1128 png_voidp error_ptr;
1129#ifdef PNG_USER_MEM_SUPPORTED
1130 png_free_ptr free_fn;
1131#endif
1132
1133 png_debug(1, "in png_write_destroy");
1134
1135 /* Free any memory zlib uses */
1136 deflateEnd(&png_ptr->zstream);
1137
1138 /* Free our memory. png_free checks NULL for us. */
1139 png_free(png_ptr, png_ptr->zbuf);
1140 png_free(png_ptr, png_ptr->row_buf);
1141#ifdef PNG_WRITE_FILTER_SUPPORTED
1142 png_free(png_ptr, png_ptr->prev_row);
1143 png_free(png_ptr, png_ptr->sub_row);
1144 png_free(png_ptr, png_ptr->up_row);
1145 png_free(png_ptr, png_ptr->avg_row);
1146 png_free(png_ptr, png_ptr->paeth_row);
1147#endif
1148
1149#ifdef PNG_TIME_RFC1123_SUPPORTED
1150 png_free(png_ptr, png_ptr->time_buffer);
1151#endif
1152
1153#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1154 png_free(png_ptr, png_ptr->prev_filters);
1155 png_free(png_ptr, png_ptr->filter_weights);
1156 png_free(png_ptr, png_ptr->inv_filter_weights);
1157 png_free(png_ptr, png_ptr->filter_costs);
1158 png_free(png_ptr, png_ptr->inv_filter_costs);
1159#endif
1160
1161#ifdef PNG_SETJMP_SUPPORTED
1162 /* Reset structure */
1163 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1164#endif
1165
1166 error_fn = png_ptr->error_fn;
1167 warning_fn = png_ptr->warning_fn;
1168 error_ptr = png_ptr->error_ptr;
1169#ifdef PNG_USER_MEM_SUPPORTED
1170 free_fn = png_ptr->free_fn;
1171#endif
1172
1173 png_memset(png_ptr, 0, png_sizeof(png_struct));
1174
1175 png_ptr->error_fn = error_fn;
1176 png_ptr->warning_fn = warning_fn;
1177 png_ptr->error_ptr = error_ptr;
1178#ifdef PNG_USER_MEM_SUPPORTED
1179 png_ptr->free_fn = free_fn;
1180#endif
1181
1182#ifdef PNG_SETJMP_SUPPORTED
1183 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1184#endif
1185}
1186
1187/* Allow the application to select one or more row filters to use. */
1188void PNGAPI
1189png_set_filter(png_structp png_ptr, int method, int filters)
1190{
1191 png_debug(1, "in png_set_filter");
1192
1193 if (png_ptr == NULL)
1194 return;
1195#ifdef PNG_MNG_FEATURES_SUPPORTED
1196 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1197 (method == PNG_INTRAPIXEL_DIFFERENCING))
1198 method = PNG_FILTER_TYPE_BASE;
1199#endif
1200 if (method == PNG_FILTER_TYPE_BASE)
1201 {
1202 switch (filters & (PNG_ALL_FILTERS | 0x07))
1203 {
1204 case PNG_FILTER_VALUE_NONE:
1205 png_ptr->do_filter = PNG_FILTER_NONE; break;
1206#ifdef PNG_WRITE_FILTER_SUPPORTED
1207 case 5:
1208 case 6:
1209 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1210 break;
1211 case PNG_FILTER_VALUE_SUB:
1212 png_ptr->do_filter = PNG_FILTER_SUB; break;
1213 case PNG_FILTER_VALUE_UP:
1214 png_ptr->do_filter = PNG_FILTER_UP; break;
1215 case PNG_FILTER_VALUE_AVG:
1216 png_ptr->do_filter = PNG_FILTER_AVG; break;
1217 case PNG_FILTER_VALUE_PAETH:
1218 png_ptr->do_filter = PNG_FILTER_PAETH; break;
1219 default: png_ptr->do_filter = (png_byte)filters; break;
1220#else
1221 default: png_warning(png_ptr, "Unknown row filter for method 0");
1222 break;
1223#endif /* PNG_WRITE_FILTER_SUPPORTED */
1224 }
1225
1226 /* If we have allocated the row_buf, this means we have already started
1227 * with the image and we should have allocated all of the filter buffers
1228 * that have been selected. If prev_row isn't already allocated, then
1229 * it is too late to start using the filters that need it, since we
1230 * will be missing the data in the previous row. If an application
1231 * wants to start and stop using particular filters during compression,
1232 * it should start out with all of the filters, and then add and
1233 * remove them after the start of compression.
1234 */
1235 if (png_ptr->row_buf != NULL)
1236 {
1237#ifdef PNG_WRITE_FILTER_SUPPORTED
1238 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1239 {
1240 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1241 (png_ptr->rowbytes + 1));
1242 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1243 }
1244
1245 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1246 {
1247 if (png_ptr->prev_row == NULL)
1248 {
1249 png_warning(png_ptr, "Can't add Up filter after starting");
1250 png_ptr->do_filter &= ~PNG_FILTER_UP;
1251 }
1252 else
1253 {
1254 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1255 (png_ptr->rowbytes + 1));
1256 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1257 }
1258 }
1259
1260 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1261 {
1262 if (png_ptr->prev_row == NULL)
1263 {
1264 png_warning(png_ptr, "Can't add Average filter after starting");
1265 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1266 }
1267 else
1268 {
1269 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1270 (png_ptr->rowbytes + 1));
1271 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1272 }
1273 }
1274
1275 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1276 png_ptr->paeth_row == NULL)
1277 {
1278 if (png_ptr->prev_row == NULL)
1279 {
1280 png_warning(png_ptr, "Can't add Paeth filter after starting");
1281 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1282 }
1283 else
1284 {
1285 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1286 (png_ptr->rowbytes + 1));
1287 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1288 }
1289 }
1290
1291 if (png_ptr->do_filter == PNG_NO_FILTERS)
1292#endif /* PNG_WRITE_FILTER_SUPPORTED */
1293 png_ptr->do_filter = PNG_FILTER_NONE;
1294 }
1295 }
1296 else
1297 png_error(png_ptr, "Unknown custom filter method");
1298}
1299
1300/* This allows us to influence the way in which libpng chooses the "best"
1301 * filter for the current scanline. While the "minimum-sum-of-absolute-
1302 * differences metric is relatively fast and effective, there is some
1303 * question as to whether it can be improved upon by trying to keep the
1304 * filtered data going to zlib more consistent, hopefully resulting in
1305 * better compression.
1306 */
1307#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
1308void PNGAPI
1309png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1310 int num_weights, png_doublep filter_weights,
1311 png_doublep filter_costs)
1312{
1313 int i;
1314
1315 png_debug(1, "in png_set_filter_heuristics");
1316
1317 if (png_ptr == NULL)
1318 return;
1319 if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1320 {
1321 png_warning(png_ptr, "Unknown filter heuristic method");
1322 return;
1323 }
1324
1325 if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1326 {
1327 heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1328 }
1329
1330 if (num_weights < 0 || filter_weights == NULL ||
1331 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1332 {
1333 num_weights = 0;
1334 }
1335
1336 png_ptr->num_prev_filters = (png_byte)num_weights;
1337 png_ptr->heuristic_method = (png_byte)heuristic_method;
1338
1339 if (num_weights > 0)
1340 {
1341 if (png_ptr->prev_filters == NULL)
1342 {
1343 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1344 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1345
1346 /* To make sure that the weighting starts out fairly */
1347 for (i = 0; i < num_weights; i++)
1348 {
1349 png_ptr->prev_filters[i] = 255;
1350 }
1351 }
1352
1353 if (png_ptr->filter_weights == NULL)
1354 {
1355 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1356 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1357
1358 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1359 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1360 for (i = 0; i < num_weights; i++)
1361 {
1362 png_ptr->inv_filter_weights[i] =
1363 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1364 }
1365 }
1366
1367 for (i = 0; i < num_weights; i++)
1368 {
1369 if (filter_weights[i] < 0.0)
1370 {
1371 png_ptr->inv_filter_weights[i] =
1372 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1373 }
1374 else
1375 {
1376 png_ptr->inv_filter_weights[i] =
1377 (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1378 png_ptr->filter_weights[i] =
1379 (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1380 }
1381 }
1382 }
1383
1384 /* If, in the future, there are other filter methods, this would
1385 * need to be based on png_ptr->filter.
1386 */
1387 if (png_ptr->filter_costs == NULL)
1388 {
1389 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1390 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1391
1392 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1393 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1394
1395 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1396 {
1397 png_ptr->inv_filter_costs[i] =
1398 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1399 }
1400 }
1401
1402 /* Here is where we set the relative costs of the different filters. We
1403 * should take the desired compression level into account when setting
1404 * the costs, so that Paeth, for instance, has a high relative cost at low
1405 * compression levels, while it has a lower relative cost at higher
1406 * compression settings. The filter types are in order of increasing
1407 * relative cost, so it would be possible to do this with an algorithm.
1408 */
1409 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1410 {
1411 if (filter_costs == NULL || filter_costs[i] < 0.0)
1412 {
1413 png_ptr->inv_filter_costs[i] =
1414 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1415 }
1416 else if (filter_costs[i] >= 1.0)
1417 {
1418 png_ptr->inv_filter_costs[i] =
1419 (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1420 png_ptr->filter_costs[i] =
1421 (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1422 }
1423 }
1424}
1425#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1426
1427void PNGAPI
1428png_set_compression_level(png_structp png_ptr, int level)
1429{
1430 png_debug(1, "in png_set_compression_level");
1431
1432 if (png_ptr == NULL)
1433 return;
1434 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1435 png_ptr->zlib_level = level;
1436}
1437
1438void PNGAPI
1439png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1440{
1441 png_debug(1, "in png_set_compression_mem_level");
1442
1443 if (png_ptr == NULL)
1444 return;
1445 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1446 png_ptr->zlib_mem_level = mem_level;
1447}
1448
1449void PNGAPI
1450png_set_compression_strategy(png_structp png_ptr, int strategy)
1451{
1452 png_debug(1, "in png_set_compression_strategy");
1453
1454 if (png_ptr == NULL)
1455 return;
1456 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1457 png_ptr->zlib_strategy = strategy;
1458}
1459
1460void PNGAPI
1461png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1462{
1463 if (png_ptr == NULL)
1464 return;
1465 if (window_bits > 15)
1466 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1467 else if (window_bits < 8)
1468 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1469#ifndef WBITS_8_OK
1470 /* Avoid libpng bug with 256-byte windows */
1471 if (window_bits == 8)
1472 {
1473 png_warning(png_ptr, "Compression window is being reset to 512");
1474 window_bits = 9;
1475 }
1476#endif
1477 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1478 png_ptr->zlib_window_bits = window_bits;
1479}
1480
1481void PNGAPI
1482png_set_compression_method(png_structp png_ptr, int method)
1483{
1484 png_debug(1, "in png_set_compression_method");
1485
1486 if (png_ptr == NULL)
1487 return;
1488 if (method != 8)
1489 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1490 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1491 png_ptr->zlib_method = method;
1492}
1493
1494void PNGAPI
1495png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1496{
1497 if (png_ptr == NULL)
1498 return;
1499 png_ptr->write_row_fn = write_row_fn;
1500}
1501
1502#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1503void PNGAPI
1504png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1505 write_user_transform_fn)
1506{
1507 png_debug(1, "in png_set_write_user_transform_fn");
1508
1509 if (png_ptr == NULL)
1510 return;
1511 png_ptr->transformations |= PNG_USER_TRANSFORM;
1512 png_ptr->write_user_transform_fn = write_user_transform_fn;
1513}
1514#endif
1515
1516
1517#ifdef PNG_INFO_IMAGE_SUPPORTED
1518void PNGAPI
1519png_write_png(png_structp png_ptr, png_infop info_ptr,
1520 int transforms, voidp params)
1521{
1522 if (png_ptr == NULL || info_ptr == NULL)
1523 return;
1524
1525 /* Write the file header information. */
1526 png_write_info(png_ptr, info_ptr);
1527
1528 /* ------ these transformations don't touch the info structure ------- */
1529
1530#ifdef PNG_WRITE_INVERT_SUPPORTED
1531 /* Invert monochrome pixels */
1532 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1533 png_set_invert_mono(png_ptr);
1534#endif
1535
1536#ifdef PNG_WRITE_SHIFT_SUPPORTED
1537 /* Shift the pixels up to a legal bit depth and fill in
1538 * as appropriate to correctly scale the image.
1539 */
1540 if ((transforms & PNG_TRANSFORM_SHIFT)
1541 && (info_ptr->valid & PNG_INFO_sBIT))
1542 png_set_shift(png_ptr, &info_ptr->sig_bit);
1543#endif
1544
1545#ifdef PNG_WRITE_PACK_SUPPORTED
1546 /* Pack pixels into bytes */
1547 if (transforms & PNG_TRANSFORM_PACKING)
1548 png_set_packing(png_ptr);
1549#endif
1550
1551#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1552 /* Swap location of alpha bytes from ARGB to RGBA */
1553 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1554 png_set_swap_alpha(png_ptr);
1555#endif
1556
1557#ifdef PNG_WRITE_FILLER_SUPPORTED
1558 /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
1559 if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1560 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1561 else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1562 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1563#endif
1564
1565#ifdef PNG_WRITE_BGR_SUPPORTED
1566 /* Flip BGR pixels to RGB */
1567 if (transforms & PNG_TRANSFORM_BGR)
1568 png_set_bgr(png_ptr);
1569#endif
1570
1571#ifdef PNG_WRITE_SWAP_SUPPORTED
1572 /* Swap bytes of 16-bit files to most significant byte first */
1573 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1574 png_set_swap(png_ptr);
1575#endif
1576
1577#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1578 /* Swap bits of 1, 2, 4 bit packed pixel formats */
1579 if (transforms & PNG_TRANSFORM_PACKSWAP)
1580 png_set_packswap(png_ptr);
1581#endif
1582
1583#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1584 /* Invert the alpha channel from opacity to transparency */
1585 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1586 png_set_invert_alpha(png_ptr);
1587#endif
1588
1589 /* ----------------------- end of transformations ------------------- */
1590
1591 /* Write the bits */
1592 if (info_ptr->valid & PNG_INFO_IDAT)
1593 png_write_image(png_ptr, info_ptr->row_pointers);
1594
1595 /* It is REQUIRED to call this to finish writing the rest of the file */
1596 png_write_end(png_ptr, info_ptr);
1597
1598 PNG_UNUSED(transforms) /* Quiet compiler warnings */
1599 PNG_UNUSED(params)
1600}
1601#endif
1602#endif /* PNG_WRITE_SUPPORTED */
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