2
/* pngwrite.c - general routines to write a PNG file
4
* Last changed in libpng 1.2.37 [June 4, 2009]
5
* Copyright (c) 1998-2009 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.)
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
14
/* Get internal access to png.h */
17
#ifdef PNG_WRITE_SUPPORTED
19
/* Writes all the PNG information. This is the suggested way to use the
20
* library. If you have a new chunk to add, make a function to write it,
21
* and put it in the correct location here. If you want the chunk written
22
* after the image data, put it in png_write_end(). I strongly encourage
23
* you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
24
* the chunk, as that will keep the code from breaking if you want to just
25
* write a plain PNG file. If you have long comments, I suggest writing
26
* them in png_write_end(), and compressing them.
29
png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
31
png_debug(1, "in png_write_info_before_PLTE");
32
if (png_ptr == NULL || info_ptr == NULL)
34
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
36
png_write_sig(png_ptr); /* Write PNG signature */
37
#if defined(PNG_MNG_FEATURES_SUPPORTED)
38
if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
40
png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
41
png_ptr->mng_features_permitted=0;
44
/* Write IHDR information. */
45
png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
46
info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
47
info_ptr->filter_type,
48
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
49
info_ptr->interlace_type);
53
/* The rest of these check to see if the valid field has the appropriate
54
* flag set, and if it does, writes the chunk.
56
#if defined(PNG_WRITE_gAMA_SUPPORTED)
57
if (info_ptr->valid & PNG_INFO_gAMA)
59
# ifdef PNG_FLOATING_POINT_SUPPORTED
60
png_write_gAMA(png_ptr, info_ptr->gamma);
62
#ifdef PNG_FIXED_POINT_SUPPORTED
63
png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
68
#if defined(PNG_WRITE_sRGB_SUPPORTED)
69
if (info_ptr->valid & PNG_INFO_sRGB)
70
png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
72
#if defined(PNG_WRITE_iCCP_SUPPORTED)
73
if (info_ptr->valid & PNG_INFO_iCCP)
74
png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
75
info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
77
#if defined(PNG_WRITE_sBIT_SUPPORTED)
78
if (info_ptr->valid & PNG_INFO_sBIT)
79
png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
81
#if defined(PNG_WRITE_cHRM_SUPPORTED)
82
if (info_ptr->valid & PNG_INFO_cHRM)
84
#ifdef PNG_FLOATING_POINT_SUPPORTED
85
png_write_cHRM(png_ptr,
86
info_ptr->x_white, info_ptr->y_white,
87
info_ptr->x_red, info_ptr->y_red,
88
info_ptr->x_green, info_ptr->y_green,
89
info_ptr->x_blue, info_ptr->y_blue);
91
# ifdef PNG_FIXED_POINT_SUPPORTED
92
png_write_cHRM_fixed(png_ptr,
93
info_ptr->int_x_white, info_ptr->int_y_white,
94
info_ptr->int_x_red, info_ptr->int_y_red,
95
info_ptr->int_x_green, info_ptr->int_y_green,
96
info_ptr->int_x_blue, info_ptr->int_y_blue);
101
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
102
if (info_ptr->unknown_chunks_num)
104
png_unknown_chunk *up;
106
png_debug(5, "writing extra chunks");
108
for (up = info_ptr->unknown_chunks;
109
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
112
int keep=png_handle_as_unknown(png_ptr, up->name);
113
if (keep != PNG_HANDLE_CHUNK_NEVER &&
114
up->location && !(up->location & PNG_HAVE_PLTE) &&
115
!(up->location & PNG_HAVE_IDAT) &&
116
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
117
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
120
png_warning(png_ptr, "Writing zero-length unknown chunk");
121
png_write_chunk(png_ptr, up->name, up->data, up->size);
126
png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
131
png_write_info(png_structp png_ptr, png_infop info_ptr)
133
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
137
png_debug(1, "in png_write_info");
139
if (png_ptr == NULL || info_ptr == NULL)
142
png_write_info_before_PLTE(png_ptr, info_ptr);
144
if (info_ptr->valid & PNG_INFO_PLTE)
145
png_write_PLTE(png_ptr, info_ptr->palette,
146
(png_uint_32)info_ptr->num_palette);
147
else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
148
png_error(png_ptr, "Valid palette required for paletted images");
150
#if defined(PNG_WRITE_tRNS_SUPPORTED)
151
if (info_ptr->valid & PNG_INFO_tRNS)
153
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
154
/* Invert the alpha channel (in tRNS) */
155
if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
156
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
159
for (j=0; j<(int)info_ptr->num_trans; j++)
160
info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
163
png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
164
info_ptr->num_trans, info_ptr->color_type);
167
#if defined(PNG_WRITE_bKGD_SUPPORTED)
168
if (info_ptr->valid & PNG_INFO_bKGD)
169
png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
171
#if defined(PNG_WRITE_hIST_SUPPORTED)
172
if (info_ptr->valid & PNG_INFO_hIST)
173
png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
175
#if defined(PNG_WRITE_oFFs_SUPPORTED)
176
if (info_ptr->valid & PNG_INFO_oFFs)
177
png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
178
info_ptr->offset_unit_type);
180
#if defined(PNG_WRITE_pCAL_SUPPORTED)
181
if (info_ptr->valid & PNG_INFO_pCAL)
182
png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
183
info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
184
info_ptr->pcal_units, info_ptr->pcal_params);
187
#if defined(PNG_sCAL_SUPPORTED)
188
if (info_ptr->valid & PNG_INFO_sCAL)
189
#if defined(PNG_WRITE_sCAL_SUPPORTED)
190
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
191
png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
192
info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
193
#else /* !FLOATING_POINT */
194
#ifdef PNG_FIXED_POINT_SUPPORTED
195
png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
196
info_ptr->scal_s_width, info_ptr->scal_s_height);
197
#endif /* FIXED_POINT */
198
#endif /* FLOATING_POINT */
199
#else /* !WRITE_sCAL */
201
"png_write_sCAL not supported; sCAL chunk not written.");
202
#endif /* WRITE_sCAL */
205
#if defined(PNG_WRITE_pHYs_SUPPORTED)
206
if (info_ptr->valid & PNG_INFO_pHYs)
207
png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
208
info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
211
#if defined(PNG_WRITE_tIME_SUPPORTED)
212
if (info_ptr->valid & PNG_INFO_tIME)
214
png_write_tIME(png_ptr, &(info_ptr->mod_time));
215
png_ptr->mode |= PNG_WROTE_tIME;
219
#if defined(PNG_WRITE_sPLT_SUPPORTED)
220
if (info_ptr->valid & PNG_INFO_sPLT)
221
for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
222
png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
225
#if defined(PNG_WRITE_TEXT_SUPPORTED)
226
/* Check to see if we need to write text chunks */
227
for (i = 0; i < info_ptr->num_text; i++)
229
png_debug2(2, "Writing header text chunk %d, type %d", i,
230
info_ptr->text[i].compression);
231
/* An internationalized chunk? */
232
if (info_ptr->text[i].compression > 0)
234
#if defined(PNG_WRITE_iTXt_SUPPORTED)
235
/* Write international chunk */
236
png_write_iTXt(png_ptr,
237
info_ptr->text[i].compression,
238
info_ptr->text[i].key,
239
info_ptr->text[i].lang,
240
info_ptr->text[i].lang_key,
241
info_ptr->text[i].text);
243
png_warning(png_ptr, "Unable to write international text");
245
/* Mark this chunk as written */
246
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
248
/* If we want a compressed text chunk */
249
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
251
#if defined(PNG_WRITE_zTXt_SUPPORTED)
252
/* Write compressed chunk */
253
png_write_zTXt(png_ptr, info_ptr->text[i].key,
254
info_ptr->text[i].text, 0,
255
info_ptr->text[i].compression);
257
png_warning(png_ptr, "Unable to write compressed text");
259
/* Mark this chunk as written */
260
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
262
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
264
#if defined(PNG_WRITE_tEXt_SUPPORTED)
265
/* Write uncompressed chunk */
266
png_write_tEXt(png_ptr, info_ptr->text[i].key,
267
info_ptr->text[i].text,
269
/* Mark this chunk as written */
270
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
273
png_warning(png_ptr, "Unable to write uncompressed text");
279
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
280
if (info_ptr->unknown_chunks_num)
282
png_unknown_chunk *up;
284
png_debug(5, "writing extra chunks");
286
for (up = info_ptr->unknown_chunks;
287
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
290
int keep=png_handle_as_unknown(png_ptr, up->name);
291
if (keep != PNG_HANDLE_CHUNK_NEVER &&
292
up->location && (up->location & PNG_HAVE_PLTE) &&
293
!(up->location & PNG_HAVE_IDAT) &&
294
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
295
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
297
png_write_chunk(png_ptr, up->name, up->data, up->size);
304
/* Writes the end of the PNG file. If you don't want to write comments or
305
* time information, you can pass NULL for info. If you already wrote these
306
* in png_write_info(), do not write them again here. If you have long
307
* comments, I suggest writing them here, and compressing them.
310
png_write_end(png_structp png_ptr, png_infop info_ptr)
312
png_debug(1, "in png_write_end");
315
if (!(png_ptr->mode & PNG_HAVE_IDAT))
316
png_error(png_ptr, "No IDATs written into file");
318
/* See if user wants us to write information chunks */
319
if (info_ptr != NULL)
321
#if defined(PNG_WRITE_TEXT_SUPPORTED)
322
int i; /* Local index variable */
324
#if defined(PNG_WRITE_tIME_SUPPORTED)
325
/* Check to see if user has supplied a time chunk */
326
if ((info_ptr->valid & PNG_INFO_tIME) &&
327
!(png_ptr->mode & PNG_WROTE_tIME))
328
png_write_tIME(png_ptr, &(info_ptr->mod_time));
330
#if defined(PNG_WRITE_TEXT_SUPPORTED)
331
/* Loop through comment chunks */
332
for (i = 0; i < info_ptr->num_text; i++)
334
png_debug2(2, "Writing trailer text chunk %d, type %d", i,
335
info_ptr->text[i].compression);
336
/* An internationalized chunk? */
337
if (info_ptr->text[i].compression > 0)
339
#if defined(PNG_WRITE_iTXt_SUPPORTED)
340
/* Write international chunk */
341
png_write_iTXt(png_ptr,
342
info_ptr->text[i].compression,
343
info_ptr->text[i].key,
344
info_ptr->text[i].lang,
345
info_ptr->text[i].lang_key,
346
info_ptr->text[i].text);
348
png_warning(png_ptr, "Unable to write international text");
350
/* Mark this chunk as written */
351
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
353
else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
355
#if defined(PNG_WRITE_zTXt_SUPPORTED)
356
/* Write compressed chunk */
357
png_write_zTXt(png_ptr, info_ptr->text[i].key,
358
info_ptr->text[i].text, 0,
359
info_ptr->text[i].compression);
361
png_warning(png_ptr, "Unable to write compressed text");
363
/* Mark this chunk as written */
364
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
366
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
368
#if defined(PNG_WRITE_tEXt_SUPPORTED)
369
/* Write uncompressed chunk */
370
png_write_tEXt(png_ptr, info_ptr->text[i].key,
371
info_ptr->text[i].text, 0);
373
png_warning(png_ptr, "Unable to write uncompressed text");
376
/* Mark this chunk as written */
377
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
381
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
382
if (info_ptr->unknown_chunks_num)
384
png_unknown_chunk *up;
386
png_debug(5, "writing extra chunks");
388
for (up = info_ptr->unknown_chunks;
389
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
392
int keep=png_handle_as_unknown(png_ptr, up->name);
393
if (keep != PNG_HANDLE_CHUNK_NEVER &&
394
up->location && (up->location & PNG_AFTER_IDAT) &&
395
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
396
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
398
png_write_chunk(png_ptr, up->name, up->data, up->size);
405
png_ptr->mode |= PNG_AFTER_IDAT;
407
/* Write end of PNG file */
408
png_write_IEND(png_ptr);
409
/* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
410
* and restored again in libpng-1.2.30, may cause some applications that
411
* do not set png_ptr->output_flush_fn to crash. If your application
412
* experiences a problem, please try building libpng with
413
* PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
414
* png-mng-implement at lists.sf.net . This kludge will be removed
417
#if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
418
defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
423
#if defined(PNG_WRITE_tIME_SUPPORTED)
424
#if !defined(_WIN32_WCE)
425
/* "time.h" functions are not supported on WindowsCE */
427
png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
429
png_debug(1, "in png_convert_from_struct_tm");
430
ptime->year = (png_uint_16)(1900 + ttime->tm_year);
431
ptime->month = (png_byte)(ttime->tm_mon + 1);
432
ptime->day = (png_byte)ttime->tm_mday;
433
ptime->hour = (png_byte)ttime->tm_hour;
434
ptime->minute = (png_byte)ttime->tm_min;
435
ptime->second = (png_byte)ttime->tm_sec;
439
png_convert_from_time_t(png_timep ptime, time_t ttime)
443
png_debug(1, "in png_convert_from_time_t");
444
tbuf = gmtime(&ttime);
445
png_convert_from_struct_tm(ptime, tbuf);
450
/* Initialize png_ptr structure, and allocate any memory needed */
452
png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
453
png_error_ptr error_fn, png_error_ptr warn_fn)
455
#ifdef PNG_USER_MEM_SUPPORTED
456
return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
457
warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
460
/* Alternate initialize png_ptr structure, and allocate any memory needed */
462
png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
463
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
464
png_malloc_ptr malloc_fn, png_free_ptr free_fn)
466
#endif /* PNG_USER_MEM_SUPPORTED */
467
#ifdef PNG_SETJMP_SUPPORTED
471
#ifdef PNG_SETJMP_SUPPORTED
472
#ifdef USE_FAR_KEYWORD
477
png_debug(1, "in png_create_write_struct");
478
#ifdef PNG_USER_MEM_SUPPORTED
479
png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
480
(png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
482
png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
483
#endif /* PNG_USER_MEM_SUPPORTED */
487
/* Added at libpng-1.2.6 */
488
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
489
png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
490
png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
493
#ifdef PNG_SETJMP_SUPPORTED
494
#ifdef USE_FAR_KEYWORD
497
if (setjmp(png_ptr->jmpbuf))
500
png_free(png_ptr, png_ptr->zbuf);
502
png_destroy_struct(png_ptr);
505
#ifdef USE_FAR_KEYWORD
506
png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
510
#ifdef PNG_USER_MEM_SUPPORTED
511
png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
512
#endif /* PNG_USER_MEM_SUPPORTED */
513
png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
520
if (user_png_ver[i] != png_libpng_ver[i])
521
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
522
} while (png_libpng_ver[i++]);
525
if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
527
/* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
528
* we must recompile any applications that use any older library version.
529
* For versions after libpng 1.0, we will be compatible, so we need
530
* only check the first digit.
532
if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
533
(user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
534
(user_png_ver[0] == '0' && user_png_ver[2] < '9'))
536
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
540
png_snprintf(msg, 80,
541
"Application was compiled with png.h from libpng-%.20s",
543
png_warning(png_ptr, msg);
545
png_snprintf(msg, 80,
546
"Application is running with png.c from libpng-%.20s",
548
png_warning(png_ptr, msg);
550
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
554
"Incompatible libpng version in application and library");
558
/* Initialize zbuf - compression buffer */
559
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
560
png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
561
(png_uint_32)png_ptr->zbuf_size);
563
png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
566
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
567
png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
568
1, png_doublep_NULL, png_doublep_NULL);
571
#ifdef PNG_SETJMP_SUPPORTED
572
/* Applications that neglect to set up their own setjmp() and then encounter
573
a png_error() will longjmp here. Since the jmpbuf is then meaningless we
574
abort instead of returning. */
575
#ifdef USE_FAR_KEYWORD
578
png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
580
if (setjmp(png_ptr->jmpbuf))
587
/* Initialize png_ptr structure, and allocate any memory needed */
588
#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
590
#undef png_write_init
592
png_write_init(png_structp png_ptr)
594
/* We only come here via pre-1.0.7-compiled applications */
595
png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
599
png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
600
png_size_t png_struct_size, png_size_t png_info_size)
602
/* We only come here via pre-1.0.12-compiled applications */
603
if (png_ptr == NULL) return;
604
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
605
if (png_sizeof(png_struct) > png_struct_size ||
606
png_sizeof(png_info) > png_info_size)
609
png_ptr->warning_fn=NULL;
612
png_snprintf(msg, 80,
613
"Application was compiled with png.h from libpng-%.20s",
615
png_warning(png_ptr, msg);
617
png_snprintf(msg, 80,
618
"Application is running with png.c from libpng-%.20s",
620
png_warning(png_ptr, msg);
623
if (png_sizeof(png_struct) > png_struct_size)
625
png_ptr->error_fn=NULL;
626
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
630
"The png struct allocated by the application for writing is too small.");
632
if (png_sizeof(png_info) > png_info_size)
634
png_ptr->error_fn=NULL;
635
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
639
"The info struct allocated by the application for writing is too small.");
641
png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
643
#endif /* PNG_1_0_X || PNG_1_2_X */
647
png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
648
png_size_t png_struct_size)
650
png_structp png_ptr=*ptr_ptr;
651
#ifdef PNG_SETJMP_SUPPORTED
652
jmp_buf tmp_jmp; /* To save current jump buffer */
662
if (user_png_ver[i] != png_libpng_ver[i])
664
#ifdef PNG_LEGACY_SUPPORTED
665
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
667
png_ptr->warning_fn=NULL;
669
"Application uses deprecated png_write_init() and should be recompiled.");
673
} while (png_libpng_ver[i++]);
675
png_debug(1, "in png_write_init_3");
677
#ifdef PNG_SETJMP_SUPPORTED
678
/* Save jump buffer and error functions */
679
png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
682
if (png_sizeof(png_struct) > png_struct_size)
684
png_destroy_struct(png_ptr);
685
png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
689
/* Reset all variables to 0 */
690
png_memset(png_ptr, 0, png_sizeof(png_struct));
692
/* Added at libpng-1.2.6 */
693
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
694
png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
695
png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
698
#ifdef PNG_SETJMP_SUPPORTED
699
/* Restore jump buffer */
700
png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
703
png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
706
/* Initialize zbuf - compression buffer */
707
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
708
png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
709
(png_uint_32)png_ptr->zbuf_size);
711
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
712
png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
713
1, png_doublep_NULL, png_doublep_NULL);
717
/* Write a few rows of image data. If the image is interlaced,
718
* either you will have to write the 7 sub images, or, if you
719
* have called png_set_interlace_handling(), you will have to
720
* "write" the image seven times.
723
png_write_rows(png_structp png_ptr, png_bytepp row,
724
png_uint_32 num_rows)
726
png_uint_32 i; /* Row counter */
727
png_bytepp rp; /* Row pointer */
729
png_debug(1, "in png_write_rows");
734
/* Loop through the rows */
735
for (i = 0, rp = row; i < num_rows; i++, rp++)
737
png_write_row(png_ptr, *rp);
741
/* Write the image. You only need to call this function once, even
742
* if you are writing an interlaced image.
745
png_write_image(png_structp png_ptr, png_bytepp image)
747
png_uint_32 i; /* Row index */
748
int pass, num_pass; /* Pass variables */
749
png_bytepp rp; /* Points to current row */
754
png_debug(1, "in png_write_image");
755
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
756
/* Initialize interlace handling. If image is not interlaced,
757
* this will set pass to 1
759
num_pass = png_set_interlace_handling(png_ptr);
763
/* Loop through passes */
764
for (pass = 0; pass < num_pass; pass++)
766
/* Loop through image */
767
for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
769
png_write_row(png_ptr, *rp);
774
/* Called by user to write a row of image data */
776
png_write_row(png_structp png_ptr, png_bytep row)
780
png_debug2(1, "in png_write_row (row %ld, pass %d)",
781
png_ptr->row_number, png_ptr->pass);
783
/* Initialize transformations and other stuff if first time */
784
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
786
/* Make sure we wrote the header info */
787
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
789
"png_write_info was never called before png_write_row.");
791
/* Check for transforms that have been set but were defined out */
792
#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
793
if (png_ptr->transformations & PNG_INVERT_MONO)
794
png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
796
#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
797
if (png_ptr->transformations & PNG_FILLER)
798
png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
800
#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
801
if (png_ptr->transformations & PNG_PACKSWAP)
802
png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
804
#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
805
if (png_ptr->transformations & PNG_PACK)
806
png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
808
#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
809
if (png_ptr->transformations & PNG_SHIFT)
810
png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
812
#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
813
if (png_ptr->transformations & PNG_BGR)
814
png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
816
#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
817
if (png_ptr->transformations & PNG_SWAP_BYTES)
818
png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
821
png_write_start_row(png_ptr);
824
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
825
/* If interlaced and not interested in row, return */
826
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
828
switch (png_ptr->pass)
831
if (png_ptr->row_number & 0x07)
833
png_write_finish_row(png_ptr);
838
if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
840
png_write_finish_row(png_ptr);
845
if ((png_ptr->row_number & 0x07) != 4)
847
png_write_finish_row(png_ptr);
852
if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
854
png_write_finish_row(png_ptr);
859
if ((png_ptr->row_number & 0x03) != 2)
861
png_write_finish_row(png_ptr);
866
if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
868
png_write_finish_row(png_ptr);
873
if (!(png_ptr->row_number & 0x01))
875
png_write_finish_row(png_ptr);
883
/* Set up row info for transformations */
884
png_ptr->row_info.color_type = png_ptr->color_type;
885
png_ptr->row_info.width = png_ptr->usr_width;
886
png_ptr->row_info.channels = png_ptr->usr_channels;
887
png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
888
png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
889
png_ptr->row_info.channels);
891
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
892
png_ptr->row_info.width);
894
png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
895
png_debug1(3, "row_info->width = %lu", png_ptr->row_info.width);
896
png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
897
png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
898
png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
899
png_debug1(3, "row_info->rowbytes = %lu", png_ptr->row_info.rowbytes);
901
/* Copy user's row into buffer, leaving room for filter byte. */
902
png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
903
png_ptr->row_info.rowbytes);
905
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
906
/* Handle interlacing */
907
if (png_ptr->interlaced && png_ptr->pass < 6 &&
908
(png_ptr->transformations & PNG_INTERLACE))
910
png_do_write_interlace(&(png_ptr->row_info),
911
png_ptr->row_buf + 1, png_ptr->pass);
912
/* This should always get caught above, but still ... */
913
if (!(png_ptr->row_info.width))
915
png_write_finish_row(png_ptr);
921
/* Handle other transformations */
922
if (png_ptr->transformations)
923
png_do_write_transformations(png_ptr);
925
#if defined(PNG_MNG_FEATURES_SUPPORTED)
926
/* Write filter_method 64 (intrapixel differencing) only if
927
* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
928
* 2. Libpng did not write a PNG signature (this filter_method is only
929
* used in PNG datastreams that are embedded in MNG datastreams) and
930
* 3. The application called png_permit_mng_features with a mask that
931
* included PNG_FLAG_MNG_FILTER_64 and
932
* 4. The filter_method is 64 and
933
* 5. The color_type is RGB or RGBA
935
if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
936
(png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
938
/* Intrapixel differencing */
939
png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
943
/* Find a filter if necessary, filter the row and write it out. */
944
png_write_find_filter(png_ptr, &(png_ptr->row_info));
946
if (png_ptr->write_row_fn != NULL)
947
(*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
950
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
951
/* Set the automatic flush interval or 0 to turn flushing off */
953
png_set_flush(png_structp png_ptr, int nrows)
955
png_debug(1, "in png_set_flush");
958
png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
961
/* Flush the current output buffers now */
963
png_write_flush(png_structp png_ptr)
967
png_debug(1, "in png_write_flush");
970
/* We have already written out all of the data */
971
if (png_ptr->row_number >= png_ptr->num_rows)
978
/* Compress the data */
979
ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
982
/* Check for compression errors */
985
if (png_ptr->zstream.msg != NULL)
986
png_error(png_ptr, png_ptr->zstream.msg);
988
png_error(png_ptr, "zlib error");
991
if (!(png_ptr->zstream.avail_out))
993
/* Write the IDAT and reset the zlib output buffer */
994
png_write_IDAT(png_ptr, png_ptr->zbuf,
996
png_ptr->zstream.next_out = png_ptr->zbuf;
997
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1000
} while(wrote_IDAT == 1);
1002
/* If there is any data left to be output, write it into a new IDAT */
1003
if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
1005
/* Write the IDAT and reset the zlib output buffer */
1006
png_write_IDAT(png_ptr, png_ptr->zbuf,
1007
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1008
png_ptr->zstream.next_out = png_ptr->zbuf;
1009
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1011
png_ptr->flush_rows = 0;
1014
#endif /* PNG_WRITE_FLUSH_SUPPORTED */
1016
/* Free all memory used by the write */
1018
png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1020
png_structp png_ptr = NULL;
1021
png_infop info_ptr = NULL;
1022
#ifdef PNG_USER_MEM_SUPPORTED
1023
png_free_ptr free_fn = NULL;
1024
png_voidp mem_ptr = NULL;
1027
png_debug(1, "in png_destroy_write_struct");
1028
if (png_ptr_ptr != NULL)
1030
png_ptr = *png_ptr_ptr;
1031
#ifdef PNG_USER_MEM_SUPPORTED
1032
free_fn = png_ptr->free_fn;
1033
mem_ptr = png_ptr->mem_ptr;
1037
#ifdef PNG_USER_MEM_SUPPORTED
1038
if (png_ptr != NULL)
1040
free_fn = png_ptr->free_fn;
1041
mem_ptr = png_ptr->mem_ptr;
1045
if (info_ptr_ptr != NULL)
1046
info_ptr = *info_ptr_ptr;
1048
if (info_ptr != NULL)
1050
if (png_ptr != NULL)
1052
png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1054
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1055
if (png_ptr->num_chunk_list)
1057
png_free(png_ptr, png_ptr->chunk_list);
1058
png_ptr->chunk_list=NULL;
1059
png_ptr->num_chunk_list = 0;
1064
#ifdef PNG_USER_MEM_SUPPORTED
1065
png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1066
(png_voidp)mem_ptr);
1068
png_destroy_struct((png_voidp)info_ptr);
1070
*info_ptr_ptr = NULL;
1073
if (png_ptr != NULL)
1075
png_write_destroy(png_ptr);
1076
#ifdef PNG_USER_MEM_SUPPORTED
1077
png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1078
(png_voidp)mem_ptr);
1080
png_destroy_struct((png_voidp)png_ptr);
1082
*png_ptr_ptr = NULL;
1087
/* Free any memory used in png_ptr struct (old method) */
1089
png_write_destroy(png_structp png_ptr)
1091
#ifdef PNG_SETJMP_SUPPORTED
1092
jmp_buf tmp_jmp; /* Save jump buffer */
1094
png_error_ptr error_fn;
1095
png_error_ptr warning_fn;
1096
png_voidp error_ptr;
1097
#ifdef PNG_USER_MEM_SUPPORTED
1098
png_free_ptr free_fn;
1101
png_debug(1, "in png_write_destroy");
1102
/* Free any memory zlib uses */
1103
deflateEnd(&png_ptr->zstream);
1105
/* Free our memory. png_free checks NULL for us. */
1106
png_free(png_ptr, png_ptr->zbuf);
1107
png_free(png_ptr, png_ptr->row_buf);
1108
#ifndef PNG_NO_WRITE_FILTER
1109
png_free(png_ptr, png_ptr->prev_row);
1110
png_free(png_ptr, png_ptr->sub_row);
1111
png_free(png_ptr, png_ptr->up_row);
1112
png_free(png_ptr, png_ptr->avg_row);
1113
png_free(png_ptr, png_ptr->paeth_row);
1116
#if defined(PNG_TIME_RFC1123_SUPPORTED)
1117
png_free(png_ptr, png_ptr->time_buffer);
1120
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1121
png_free(png_ptr, png_ptr->prev_filters);
1122
png_free(png_ptr, png_ptr->filter_weights);
1123
png_free(png_ptr, png_ptr->inv_filter_weights);
1124
png_free(png_ptr, png_ptr->filter_costs);
1125
png_free(png_ptr, png_ptr->inv_filter_costs);
1128
#ifdef PNG_SETJMP_SUPPORTED
1129
/* Reset structure */
1130
png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1133
error_fn = png_ptr->error_fn;
1134
warning_fn = png_ptr->warning_fn;
1135
error_ptr = png_ptr->error_ptr;
1136
#ifdef PNG_USER_MEM_SUPPORTED
1137
free_fn = png_ptr->free_fn;
1140
png_memset(png_ptr, 0, png_sizeof(png_struct));
1142
png_ptr->error_fn = error_fn;
1143
png_ptr->warning_fn = warning_fn;
1144
png_ptr->error_ptr = error_ptr;
1145
#ifdef PNG_USER_MEM_SUPPORTED
1146
png_ptr->free_fn = free_fn;
1149
#ifdef PNG_SETJMP_SUPPORTED
1150
png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1154
/* Allow the application to select one or more row filters to use. */
1156
png_set_filter(png_structp png_ptr, int method, int filters)
1158
png_debug(1, "in png_set_filter");
1159
if (png_ptr == NULL)
1161
#if defined(PNG_MNG_FEATURES_SUPPORTED)
1162
if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1163
(method == PNG_INTRAPIXEL_DIFFERENCING))
1164
method = PNG_FILTER_TYPE_BASE;
1166
if (method == PNG_FILTER_TYPE_BASE)
1168
switch (filters & (PNG_ALL_FILTERS | 0x07))
1170
#ifndef PNG_NO_WRITE_FILTER
1173
case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1174
#endif /* PNG_NO_WRITE_FILTER */
1175
case PNG_FILTER_VALUE_NONE:
1176
png_ptr->do_filter=PNG_FILTER_NONE; break;
1177
#ifndef PNG_NO_WRITE_FILTER
1178
case PNG_FILTER_VALUE_SUB:
1179
png_ptr->do_filter=PNG_FILTER_SUB; break;
1180
case PNG_FILTER_VALUE_UP:
1181
png_ptr->do_filter=PNG_FILTER_UP; break;
1182
case PNG_FILTER_VALUE_AVG:
1183
png_ptr->do_filter=PNG_FILTER_AVG; break;
1184
case PNG_FILTER_VALUE_PAETH:
1185
png_ptr->do_filter=PNG_FILTER_PAETH; break;
1186
default: png_ptr->do_filter = (png_byte)filters; break;
1188
default: png_warning(png_ptr, "Unknown row filter for method 0");
1189
#endif /* PNG_NO_WRITE_FILTER */
1192
/* If we have allocated the row_buf, this means we have already started
1193
* with the image and we should have allocated all of the filter buffers
1194
* that have been selected. If prev_row isn't already allocated, then
1195
* it is too late to start using the filters that need it, since we
1196
* will be missing the data in the previous row. If an application
1197
* wants to start and stop using particular filters during compression,
1198
* it should start out with all of the filters, and then add and
1199
* remove them after the start of compression.
1201
if (png_ptr->row_buf != NULL)
1203
#ifndef PNG_NO_WRITE_FILTER
1204
if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1206
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1207
(png_ptr->rowbytes + 1));
1208
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1211
if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1213
if (png_ptr->prev_row == NULL)
1215
png_warning(png_ptr, "Can't add Up filter after starting");
1216
png_ptr->do_filter &= ~PNG_FILTER_UP;
1220
png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1221
(png_ptr->rowbytes + 1));
1222
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1226
if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1228
if (png_ptr->prev_row == NULL)
1230
png_warning(png_ptr, "Can't add Average filter after starting");
1231
png_ptr->do_filter &= ~PNG_FILTER_AVG;
1235
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1236
(png_ptr->rowbytes + 1));
1237
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1241
if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1242
png_ptr->paeth_row == NULL)
1244
if (png_ptr->prev_row == NULL)
1246
png_warning(png_ptr, "Can't add Paeth filter after starting");
1247
png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1251
png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1252
(png_ptr->rowbytes + 1));
1253
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1257
if (png_ptr->do_filter == PNG_NO_FILTERS)
1258
#endif /* PNG_NO_WRITE_FILTER */
1259
png_ptr->do_filter = PNG_FILTER_NONE;
1263
png_error(png_ptr, "Unknown custom filter method");
1266
/* This allows us to influence the way in which libpng chooses the "best"
1267
* filter for the current scanline. While the "minimum-sum-of-absolute-
1268
* differences metric is relatively fast and effective, there is some
1269
* question as to whether it can be improved upon by trying to keep the
1270
* filtered data going to zlib more consistent, hopefully resulting in
1271
* better compression.
1273
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1275
png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1276
int num_weights, png_doublep filter_weights,
1277
png_doublep filter_costs)
1281
png_debug(1, "in png_set_filter_heuristics");
1282
if (png_ptr == NULL)
1284
if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1286
png_warning(png_ptr, "Unknown filter heuristic method");
1290
if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1292
heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1295
if (num_weights < 0 || filter_weights == NULL ||
1296
heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1301
png_ptr->num_prev_filters = (png_byte)num_weights;
1302
png_ptr->heuristic_method = (png_byte)heuristic_method;
1304
if (num_weights > 0)
1306
if (png_ptr->prev_filters == NULL)
1308
png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1309
(png_uint_32)(png_sizeof(png_byte) * num_weights));
1311
/* To make sure that the weighting starts out fairly */
1312
for (i = 0; i < num_weights; i++)
1314
png_ptr->prev_filters[i] = 255;
1318
if (png_ptr->filter_weights == NULL)
1320
png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1321
(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1323
png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1324
(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1325
for (i = 0; i < num_weights; i++)
1327
png_ptr->inv_filter_weights[i] =
1328
png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1332
for (i = 0; i < num_weights; i++)
1334
if (filter_weights[i] < 0.0)
1336
png_ptr->inv_filter_weights[i] =
1337
png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1341
png_ptr->inv_filter_weights[i] =
1342
(png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1343
png_ptr->filter_weights[i] =
1344
(png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1349
/* If, in the future, there are other filter methods, this would
1350
* need to be based on png_ptr->filter.
1352
if (png_ptr->filter_costs == NULL)
1354
png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1355
(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1357
png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1358
(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1360
for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1362
png_ptr->inv_filter_costs[i] =
1363
png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1367
/* Here is where we set the relative costs of the different filters. We
1368
* should take the desired compression level into account when setting
1369
* the costs, so that Paeth, for instance, has a high relative cost at low
1370
* compression levels, while it has a lower relative cost at higher
1371
* compression settings. The filter types are in order of increasing
1372
* relative cost, so it would be possible to do this with an algorithm.
1374
for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1376
if (filter_costs == NULL || filter_costs[i] < 0.0)
1378
png_ptr->inv_filter_costs[i] =
1379
png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1381
else if (filter_costs[i] >= 1.0)
1383
png_ptr->inv_filter_costs[i] =
1384
(png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1385
png_ptr->filter_costs[i] =
1386
(png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1390
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1393
png_set_compression_level(png_structp png_ptr, int level)
1395
png_debug(1, "in png_set_compression_level");
1396
if (png_ptr == NULL)
1398
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1399
png_ptr->zlib_level = level;
1403
png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1405
png_debug(1, "in png_set_compression_mem_level");
1406
if (png_ptr == NULL)
1408
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1409
png_ptr->zlib_mem_level = mem_level;
1413
png_set_compression_strategy(png_structp png_ptr, int strategy)
1415
png_debug(1, "in png_set_compression_strategy");
1416
if (png_ptr == NULL)
1418
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1419
png_ptr->zlib_strategy = strategy;
1423
png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1425
if (png_ptr == NULL)
1427
if (window_bits > 15)
1428
png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1429
else if (window_bits < 8)
1430
png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1432
/* Avoid libpng bug with 256-byte windows */
1433
if (window_bits == 8)
1435
png_warning(png_ptr, "Compression window is being reset to 512");
1439
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1440
png_ptr->zlib_window_bits = window_bits;
1444
png_set_compression_method(png_structp png_ptr, int method)
1446
png_debug(1, "in png_set_compression_method");
1447
if (png_ptr == NULL)
1450
png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1451
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1452
png_ptr->zlib_method = method;
1456
png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1458
if (png_ptr == NULL)
1460
png_ptr->write_row_fn = write_row_fn;
1463
#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1465
png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1466
write_user_transform_fn)
1468
png_debug(1, "in png_set_write_user_transform_fn");
1469
if (png_ptr == NULL)
1471
png_ptr->transformations |= PNG_USER_TRANSFORM;
1472
png_ptr->write_user_transform_fn = write_user_transform_fn;
1477
#if defined(PNG_INFO_IMAGE_SUPPORTED)
1479
png_write_png(png_structp png_ptr, png_infop info_ptr,
1480
int transforms, voidp params)
1482
if (png_ptr == NULL || info_ptr == NULL)
1484
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1485
/* Invert the alpha channel from opacity to transparency */
1486
if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1487
png_set_invert_alpha(png_ptr);
1490
/* Write the file header information. */
1491
png_write_info(png_ptr, info_ptr);
1493
/* ------ these transformations don't touch the info structure ------- */
1495
#if defined(PNG_WRITE_INVERT_SUPPORTED)
1496
/* Invert monochrome pixels */
1497
if (transforms & PNG_TRANSFORM_INVERT_MONO)
1498
png_set_invert_mono(png_ptr);
1501
#if defined(PNG_WRITE_SHIFT_SUPPORTED)
1502
/* Shift the pixels up to a legal bit depth and fill in
1503
* as appropriate to correctly scale the image.
1505
if ((transforms & PNG_TRANSFORM_SHIFT)
1506
&& (info_ptr->valid & PNG_INFO_sBIT))
1507
png_set_shift(png_ptr, &info_ptr->sig_bit);
1510
#if defined(PNG_WRITE_PACK_SUPPORTED)
1511
/* Pack pixels into bytes */
1512
if (transforms & PNG_TRANSFORM_PACKING)
1513
png_set_packing(png_ptr);
1516
#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1517
/* Swap location of alpha bytes from ARGB to RGBA */
1518
if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1519
png_set_swap_alpha(png_ptr);
1522
#if defined(PNG_WRITE_FILLER_SUPPORTED)
1523
/* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
1524
if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1525
png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1526
else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1527
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1530
#if defined(PNG_WRITE_BGR_SUPPORTED)
1531
/* Flip BGR pixels to RGB */
1532
if (transforms & PNG_TRANSFORM_BGR)
1533
png_set_bgr(png_ptr);
1536
#if defined(PNG_WRITE_SWAP_SUPPORTED)
1537
/* Swap bytes of 16-bit files to most significant byte first */
1538
if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1539
png_set_swap(png_ptr);
1542
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1543
/* Swap bits of 1, 2, 4 bit packed pixel formats */
1544
if (transforms & PNG_TRANSFORM_PACKSWAP)
1545
png_set_packswap(png_ptr);
1548
/* ----------------------- end of transformations ------------------- */
1550
/* Write the bits */
1551
if (info_ptr->valid & PNG_INFO_IDAT)
1552
png_write_image(png_ptr, info_ptr->row_pointers);
1554
/* It is REQUIRED to call this to finish writing the rest of the file */
1555
png_write_end(png_ptr, info_ptr);
1557
transforms = transforms; /* Quiet compiler warnings */
1561
#endif /* PNG_WRITE_SUPPORTED */