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view libs/libpng/pngwrite.c @ 13:ea928c313344
foo
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Mon, 28 Sep 2015 19:04:50 +0300 |
| parents | |
| children |
line source
2 /* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.2.31 [August 19, 2008]
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 */
11 /* get internal access to png.h */
12 #define PNG_INTERNAL
13 #include "png.h"
14 #ifdef PNG_WRITE_SUPPORTED
16 /* Writes all the PNG information. This is the suggested way to use the
17 * library. If you have a new chunk to add, make a function to write it,
18 * and put it in the correct location here. If you want the chunk written
19 * after the image data, put it in png_write_end(). I strongly encourage
20 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
21 * the chunk, as that will keep the code from breaking if you want to just
22 * write a plain PNG file. If you have long comments, I suggest writing
23 * them in png_write_end(), and compressing them.
24 */
25 void PNGAPI
26 png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
27 {
28 png_debug(1, "in png_write_info_before_PLTE\n");
29 if (png_ptr == NULL || info_ptr == NULL)
30 return;
31 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
32 {
33 png_write_sig(png_ptr); /* write PNG signature */
34 #if defined(PNG_MNG_FEATURES_SUPPORTED)
35 if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
36 {
37 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
38 png_ptr->mng_features_permitted=0;
39 }
40 #endif
41 /* write IHDR information. */
42 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
43 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
44 info_ptr->filter_type,
45 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
46 info_ptr->interlace_type);
47 #else
48 0);
49 #endif
50 /* the rest of these check to see if the valid field has the appropriate
51 flag set, and if it does, writes the chunk. */
52 #if defined(PNG_WRITE_gAMA_SUPPORTED)
53 if (info_ptr->valid & PNG_INFO_gAMA)
54 {
55 # ifdef PNG_FLOATING_POINT_SUPPORTED
56 png_write_gAMA(png_ptr, info_ptr->gamma);
57 #else
58 #ifdef PNG_FIXED_POINT_SUPPORTED
59 png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
60 # endif
61 #endif
62 }
63 #endif
64 #if defined(PNG_WRITE_sRGB_SUPPORTED)
65 if (info_ptr->valid & PNG_INFO_sRGB)
66 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
67 #endif
68 #if defined(PNG_WRITE_iCCP_SUPPORTED)
69 if (info_ptr->valid & PNG_INFO_iCCP)
70 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
71 info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
72 #endif
73 #if defined(PNG_WRITE_sBIT_SUPPORTED)
74 if (info_ptr->valid & PNG_INFO_sBIT)
75 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
76 #endif
77 #if defined(PNG_WRITE_cHRM_SUPPORTED)
78 if (info_ptr->valid & PNG_INFO_cHRM)
79 {
80 #ifdef PNG_FLOATING_POINT_SUPPORTED
81 png_write_cHRM(png_ptr,
82 info_ptr->x_white, info_ptr->y_white,
83 info_ptr->x_red, info_ptr->y_red,
84 info_ptr->x_green, info_ptr->y_green,
85 info_ptr->x_blue, info_ptr->y_blue);
86 #else
87 # ifdef PNG_FIXED_POINT_SUPPORTED
88 png_write_cHRM_fixed(png_ptr,
89 info_ptr->int_x_white, info_ptr->int_y_white,
90 info_ptr->int_x_red, info_ptr->int_y_red,
91 info_ptr->int_x_green, info_ptr->int_y_green,
92 info_ptr->int_x_blue, info_ptr->int_y_blue);
93 # endif
94 #endif
95 }
96 #endif
97 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
98 if (info_ptr->unknown_chunks_num)
99 {
100 png_unknown_chunk *up;
102 png_debug(5, "writing extra chunks\n");
104 for (up = info_ptr->unknown_chunks;
105 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
106 up++)
107 {
108 int keep=png_handle_as_unknown(png_ptr, up->name);
109 if (keep != PNG_HANDLE_CHUNK_NEVER &&
110 up->location && !(up->location & PNG_HAVE_PLTE) &&
111 !(up->location & PNG_HAVE_IDAT) &&
112 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
113 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
114 {
115 if (up->size == 0)
116 png_warning(png_ptr, "Writing zero-length unknown chunk");
117 png_write_chunk(png_ptr, up->name, up->data, up->size);
118 }
119 }
120 }
121 #endif
122 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
123 }
124 }
126 void PNGAPI
127 png_write_info(png_structp png_ptr, png_infop info_ptr)
128 {
129 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
130 int i;
131 #endif
133 png_debug(1, "in png_write_info\n");
135 if (png_ptr == NULL || info_ptr == NULL)
136 return;
138 png_write_info_before_PLTE(png_ptr, info_ptr);
140 if (info_ptr->valid & PNG_INFO_PLTE)
141 png_write_PLTE(png_ptr, info_ptr->palette,
142 (png_uint_32)info_ptr->num_palette);
143 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
144 png_error(png_ptr, "Valid palette required for paletted images");
146 #if defined(PNG_WRITE_tRNS_SUPPORTED)
147 if (info_ptr->valid & PNG_INFO_tRNS)
148 {
149 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
150 /* invert the alpha channel (in tRNS) */
151 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
152 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
153 {
154 int j;
155 for (j=0; j<(int)info_ptr->num_trans; j++)
156 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
157 }
158 #endif
159 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
160 info_ptr->num_trans, info_ptr->color_type);
161 }
162 #endif
163 #if defined(PNG_WRITE_bKGD_SUPPORTED)
164 if (info_ptr->valid & PNG_INFO_bKGD)
165 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
166 #endif
167 #if defined(PNG_WRITE_hIST_SUPPORTED)
168 if (info_ptr->valid & PNG_INFO_hIST)
169 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
170 #endif
171 #if defined(PNG_WRITE_oFFs_SUPPORTED)
172 if (info_ptr->valid & PNG_INFO_oFFs)
173 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
174 info_ptr->offset_unit_type);
175 #endif
176 #if defined(PNG_WRITE_pCAL_SUPPORTED)
177 if (info_ptr->valid & PNG_INFO_pCAL)
178 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
179 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
180 info_ptr->pcal_units, info_ptr->pcal_params);
181 #endif
182 #if defined(PNG_WRITE_sCAL_SUPPORTED)
183 if (info_ptr->valid & PNG_INFO_sCAL)
184 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
185 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
186 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
187 #else
188 #ifdef PNG_FIXED_POINT_SUPPORTED
189 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
190 info_ptr->scal_s_width, info_ptr->scal_s_height);
191 #else
192 png_warning(png_ptr,
193 "png_write_sCAL not supported; sCAL chunk not written.");
194 #endif
195 #endif
196 #endif
197 #if defined(PNG_WRITE_pHYs_SUPPORTED)
198 if (info_ptr->valid & PNG_INFO_pHYs)
199 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
200 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
201 #endif
202 #if defined(PNG_WRITE_tIME_SUPPORTED)
203 if (info_ptr->valid & PNG_INFO_tIME)
204 {
205 png_write_tIME(png_ptr, &(info_ptr->mod_time));
206 png_ptr->mode |= PNG_WROTE_tIME;
207 }
208 #endif
209 #if defined(PNG_WRITE_sPLT_SUPPORTED)
210 if (info_ptr->valid & PNG_INFO_sPLT)
211 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
212 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
213 #endif
214 #if defined(PNG_WRITE_TEXT_SUPPORTED)
215 /* Check to see if we need to write text chunks */
216 for (i = 0; i < info_ptr->num_text; i++)
217 {
218 png_debug2(2, "Writing header text chunk %d, type %d\n", i,
219 info_ptr->text[i].compression);
220 /* an internationalized chunk? */
221 if (info_ptr->text[i].compression > 0)
222 {
223 #if defined(PNG_WRITE_iTXt_SUPPORTED)
224 /* write international chunk */
225 png_write_iTXt(png_ptr,
226 info_ptr->text[i].compression,
227 info_ptr->text[i].key,
228 info_ptr->text[i].lang,
229 info_ptr->text[i].lang_key,
230 info_ptr->text[i].text);
231 #else
232 png_warning(png_ptr, "Unable to write international text");
233 #endif
234 /* Mark this chunk as written */
235 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
236 }
237 /* If we want a compressed text chunk */
238 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
239 {
240 #if defined(PNG_WRITE_zTXt_SUPPORTED)
241 /* write compressed chunk */
242 png_write_zTXt(png_ptr, info_ptr->text[i].key,
243 info_ptr->text[i].text, 0,
244 info_ptr->text[i].compression);
245 #else
246 png_warning(png_ptr, "Unable to write compressed text");
247 #endif
248 /* Mark this chunk as written */
249 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
250 }
251 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
252 {
253 #if defined(PNG_WRITE_tEXt_SUPPORTED)
254 /* write uncompressed chunk */
255 png_write_tEXt(png_ptr, info_ptr->text[i].key,
256 info_ptr->text[i].text,
257 0);
258 #else
259 png_warning(png_ptr, "Unable to write uncompressed text");
260 #endif
261 /* Mark this chunk as written */
262 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
263 }
264 }
265 #endif
266 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
267 if (info_ptr->unknown_chunks_num)
268 {
269 png_unknown_chunk *up;
271 png_debug(5, "writing extra chunks\n");
273 for (up = info_ptr->unknown_chunks;
274 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
275 up++)
276 {
277 int keep=png_handle_as_unknown(png_ptr, up->name);
278 if (keep != PNG_HANDLE_CHUNK_NEVER &&
279 up->location && (up->location & PNG_HAVE_PLTE) &&
280 !(up->location & PNG_HAVE_IDAT) &&
281 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
282 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
283 {
284 png_write_chunk(png_ptr, up->name, up->data, up->size);
285 }
286 }
287 }
288 #endif
289 }
291 /* Writes the end of the PNG file. If you don't want to write comments or
292 * time information, you can pass NULL for info. If you already wrote these
293 * in png_write_info(), do not write them again here. If you have long
294 * comments, I suggest writing them here, and compressing them.
295 */
296 void PNGAPI
297 png_write_end(png_structp png_ptr, png_infop info_ptr)
298 {
299 png_debug(1, "in png_write_end\n");
300 if (png_ptr == NULL)
301 return;
302 if (!(png_ptr->mode & PNG_HAVE_IDAT))
303 png_error(png_ptr, "No IDATs written into file");
305 /* see if user wants us to write information chunks */
306 if (info_ptr != NULL)
307 {
308 #if defined(PNG_WRITE_TEXT_SUPPORTED)
309 int i; /* local index variable */
310 #endif
311 #if defined(PNG_WRITE_tIME_SUPPORTED)
312 /* check to see if user has supplied a time chunk */
313 if ((info_ptr->valid & PNG_INFO_tIME) &&
314 !(png_ptr->mode & PNG_WROTE_tIME))
315 png_write_tIME(png_ptr, &(info_ptr->mod_time));
316 #endif
317 #if defined(PNG_WRITE_TEXT_SUPPORTED)
318 /* loop through comment chunks */
319 for (i = 0; i < info_ptr->num_text; i++)
320 {
321 png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
322 info_ptr->text[i].compression);
323 /* an internationalized chunk? */
324 if (info_ptr->text[i].compression > 0)
325 {
326 #if defined(PNG_WRITE_iTXt_SUPPORTED)
327 /* write international chunk */
328 png_write_iTXt(png_ptr,
329 info_ptr->text[i].compression,
330 info_ptr->text[i].key,
331 info_ptr->text[i].lang,
332 info_ptr->text[i].lang_key,
333 info_ptr->text[i].text);
334 #else
335 png_warning(png_ptr, "Unable to write international text");
336 #endif
337 /* Mark this chunk as written */
338 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
339 }
340 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
341 {
342 #if defined(PNG_WRITE_zTXt_SUPPORTED)
343 /* write compressed chunk */
344 png_write_zTXt(png_ptr, info_ptr->text[i].key,
345 info_ptr->text[i].text, 0,
346 info_ptr->text[i].compression);
347 #else
348 png_warning(png_ptr, "Unable to write compressed text");
349 #endif
350 /* Mark this chunk as written */
351 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
352 }
353 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
354 {
355 #if defined(PNG_WRITE_tEXt_SUPPORTED)
356 /* write uncompressed chunk */
357 png_write_tEXt(png_ptr, info_ptr->text[i].key,
358 info_ptr->text[i].text, 0);
359 #else
360 png_warning(png_ptr, "Unable to write uncompressed text");
361 #endif
363 /* Mark this chunk as written */
364 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
365 }
366 }
367 #endif
368 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
369 if (info_ptr->unknown_chunks_num)
370 {
371 png_unknown_chunk *up;
373 png_debug(5, "writing extra chunks\n");
375 for (up = info_ptr->unknown_chunks;
376 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
377 up++)
378 {
379 int keep=png_handle_as_unknown(png_ptr, up->name);
380 if (keep != PNG_HANDLE_CHUNK_NEVER &&
381 up->location && (up->location & PNG_AFTER_IDAT) &&
382 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
383 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
384 {
385 png_write_chunk(png_ptr, up->name, up->data, up->size);
386 }
387 }
388 }
389 #endif
390 }
392 png_ptr->mode |= PNG_AFTER_IDAT;
394 /* write end of PNG file */
395 png_write_IEND(png_ptr);
396 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
397 * and restored again in libpng-1.2.30, may cause some applications that
398 * do not set png_ptr->output_flush_fn to crash. If your application
399 * experiences a problem, please try building libpng with
400 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
401 * png-mng-implement at lists.sf.net . This kludge will be removed
402 * from libpng-1.4.0.
403 */
404 #if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
405 defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
406 png_flush(png_ptr);
407 #endif
408 }
410 #if defined(PNG_WRITE_tIME_SUPPORTED)
411 #if !defined(_WIN32_WCE)
412 /* "time.h" functions are not supported on WindowsCE */
413 void PNGAPI
414 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
415 {
416 png_debug(1, "in png_convert_from_struct_tm\n");
417 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
418 ptime->month = (png_byte)(ttime->tm_mon + 1);
419 ptime->day = (png_byte)ttime->tm_mday;
420 ptime->hour = (png_byte)ttime->tm_hour;
421 ptime->minute = (png_byte)ttime->tm_min;
422 ptime->second = (png_byte)ttime->tm_sec;
423 }
425 void PNGAPI
426 png_convert_from_time_t(png_timep ptime, time_t ttime)
427 {
428 struct tm *tbuf;
430 png_debug(1, "in png_convert_from_time_t\n");
431 tbuf = gmtime(&ttime);
432 png_convert_from_struct_tm(ptime, tbuf);
433 }
434 #endif
435 #endif
437 /* Initialize png_ptr structure, and allocate any memory needed */
438 png_structp PNGAPI
439 png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
440 png_error_ptr error_fn, png_error_ptr warn_fn)
441 {
442 #ifdef PNG_USER_MEM_SUPPORTED
443 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
444 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
445 }
447 /* Alternate initialize png_ptr structure, and allocate any memory needed */
448 png_structp PNGAPI
449 png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
450 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
451 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
452 {
453 #endif /* PNG_USER_MEM_SUPPORTED */
454 #ifdef PNG_SETJMP_SUPPORTED
455 volatile
456 #endif
457 png_structp png_ptr;
458 #ifdef PNG_SETJMP_SUPPORTED
459 #ifdef USE_FAR_KEYWORD
460 jmp_buf jmpbuf;
461 #endif
462 #endif
463 int i;
464 png_debug(1, "in png_create_write_struct\n");
465 #ifdef PNG_USER_MEM_SUPPORTED
466 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
467 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
468 #else
469 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
470 #endif /* PNG_USER_MEM_SUPPORTED */
471 if (png_ptr == NULL)
472 return (NULL);
474 /* added at libpng-1.2.6 */
475 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
476 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
477 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
478 #endif
480 #ifdef PNG_SETJMP_SUPPORTED
481 #ifdef USE_FAR_KEYWORD
482 if (setjmp(jmpbuf))
483 #else
484 if (setjmp(png_ptr->jmpbuf))
485 #endif
486 {
487 png_free(png_ptr, png_ptr->zbuf);
488 png_ptr->zbuf=NULL;
489 png_destroy_struct(png_ptr);
490 return (NULL);
491 }
492 #ifdef USE_FAR_KEYWORD
493 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
494 #endif
495 #endif
497 #ifdef PNG_USER_MEM_SUPPORTED
498 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
499 #endif /* PNG_USER_MEM_SUPPORTED */
500 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
502 if (user_png_ver)
503 {
504 i=0;
505 do
506 {
507 if (user_png_ver[i] != png_libpng_ver[i])
508 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
509 } while (png_libpng_ver[i++]);
510 }
512 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
513 {
514 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
515 * we must recompile any applications that use any older library version.
516 * For versions after libpng 1.0, we will be compatible, so we need
517 * only check the first digit.
518 */
519 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
520 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
521 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
522 {
523 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
524 char msg[80];
525 if (user_png_ver)
526 {
527 png_snprintf(msg, 80,
528 "Application was compiled with png.h from libpng-%.20s",
529 user_png_ver);
530 png_warning(png_ptr, msg);
531 }
532 png_snprintf(msg, 80,
533 "Application is running with png.c from libpng-%.20s",
534 png_libpng_ver);
535 png_warning(png_ptr, msg);
536 #endif
537 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
538 png_ptr->flags=0;
539 #endif
540 png_error(png_ptr,
541 "Incompatible libpng version in application and library");
542 }
543 }
545 /* initialize zbuf - compression buffer */
546 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
547 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
548 (png_uint_32)png_ptr->zbuf_size);
550 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
551 png_flush_ptr_NULL);
553 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
554 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
555 1, png_doublep_NULL, png_doublep_NULL);
556 #endif
558 #ifdef PNG_SETJMP_SUPPORTED
559 /* Applications that neglect to set up their own setjmp() and then encounter
560 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
561 abort instead of returning. */
562 #ifdef USE_FAR_KEYWORD
563 if (setjmp(jmpbuf))
564 PNG_ABORT();
565 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
566 #else
567 if (setjmp(png_ptr->jmpbuf))
568 PNG_ABORT();
569 #endif
570 #endif
571 return (png_ptr);
572 }
574 /* Initialize png_ptr structure, and allocate any memory needed */
575 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
576 /* Deprecated. */
577 #undef png_write_init
578 void PNGAPI
579 png_write_init(png_structp png_ptr)
580 {
581 /* We only come here via pre-1.0.7-compiled applications */
582 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
583 }
585 void PNGAPI
586 png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
587 png_size_t png_struct_size, png_size_t png_info_size)
588 {
589 /* We only come here via pre-1.0.12-compiled applications */
590 if (png_ptr == NULL) return;
591 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
592 if (png_sizeof(png_struct) > png_struct_size ||
593 png_sizeof(png_info) > png_info_size)
594 {
595 char msg[80];
596 png_ptr->warning_fn=NULL;
597 if (user_png_ver)
598 {
599 png_snprintf(msg, 80,
600 "Application was compiled with png.h from libpng-%.20s",
601 user_png_ver);
602 png_warning(png_ptr, msg);
603 }
604 png_snprintf(msg, 80,
605 "Application is running with png.c from libpng-%.20s",
606 png_libpng_ver);
607 png_warning(png_ptr, msg);
608 }
609 #endif
610 if (png_sizeof(png_struct) > png_struct_size)
611 {
612 png_ptr->error_fn=NULL;
613 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
614 png_ptr->flags=0;
615 #endif
616 png_error(png_ptr,
617 "The png struct allocated by the application for writing is too small.");
618 }
619 if (png_sizeof(png_info) > png_info_size)
620 {
621 png_ptr->error_fn=NULL;
622 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
623 png_ptr->flags=0;
624 #endif
625 png_error(png_ptr,
626 "The info struct allocated by the application for writing is too small.");
627 }
628 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
629 }
630 #endif /* PNG_1_0_X || PNG_1_2_X */
633 void PNGAPI
634 png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
635 png_size_t png_struct_size)
636 {
637 png_structp png_ptr=*ptr_ptr;
638 #ifdef PNG_SETJMP_SUPPORTED
639 jmp_buf tmp_jmp; /* to save current jump buffer */
640 #endif
642 int i = 0;
644 if (png_ptr == NULL)
645 return;
647 do
648 {
649 if (user_png_ver[i] != png_libpng_ver[i])
650 {
651 #ifdef PNG_LEGACY_SUPPORTED
652 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
653 #else
654 png_ptr->warning_fn=NULL;
655 png_warning(png_ptr,
656 "Application uses deprecated png_write_init() and should be recompiled.");
657 break;
658 #endif
659 }
660 } while (png_libpng_ver[i++]);
662 png_debug(1, "in png_write_init_3\n");
664 #ifdef PNG_SETJMP_SUPPORTED
665 /* save jump buffer and error functions */
666 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
667 #endif
669 if (png_sizeof(png_struct) > png_struct_size)
670 {
671 png_destroy_struct(png_ptr);
672 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
673 *ptr_ptr = png_ptr;
674 }
676 /* reset all variables to 0 */
677 png_memset(png_ptr, 0, png_sizeof(png_struct));
679 /* added at libpng-1.2.6 */
680 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
681 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
682 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
683 #endif
685 #ifdef PNG_SETJMP_SUPPORTED
686 /* restore jump buffer */
687 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
688 #endif
690 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
691 png_flush_ptr_NULL);
693 /* initialize zbuf - compression buffer */
694 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
695 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
696 (png_uint_32)png_ptr->zbuf_size);
698 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
699 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
700 1, png_doublep_NULL, png_doublep_NULL);
701 #endif
702 }
704 /* Write a few rows of image data. If the image is interlaced,
705 * either you will have to write the 7 sub images, or, if you
706 * have called png_set_interlace_handling(), you will have to
707 * "write" the image seven times.
708 */
709 void PNGAPI
710 png_write_rows(png_structp png_ptr, png_bytepp row,
711 png_uint_32 num_rows)
712 {
713 png_uint_32 i; /* row counter */
714 png_bytepp rp; /* row pointer */
716 png_debug(1, "in png_write_rows\n");
718 if (png_ptr == NULL)
719 return;
721 /* loop through the rows */
722 for (i = 0, rp = row; i < num_rows; i++, rp++)
723 {
724 png_write_row(png_ptr, *rp);
725 }
726 }
728 /* Write the image. You only need to call this function once, even
729 * if you are writing an interlaced image.
730 */
731 void PNGAPI
732 png_write_image(png_structp png_ptr, png_bytepp image)
733 {
734 png_uint_32 i; /* row index */
735 int pass, num_pass; /* pass variables */
736 png_bytepp rp; /* points to current row */
738 if (png_ptr == NULL)
739 return;
741 png_debug(1, "in png_write_image\n");
742 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
743 /* intialize interlace handling. If image is not interlaced,
744 this will set pass to 1 */
745 num_pass = png_set_interlace_handling(png_ptr);
746 #else
747 num_pass = 1;
748 #endif
749 /* loop through passes */
750 for (pass = 0; pass < num_pass; pass++)
751 {
752 /* loop through image */
753 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
754 {
755 png_write_row(png_ptr, *rp);
756 }
757 }
758 }
760 /* called by user to write a row of image data */
761 void PNGAPI
762 png_write_row(png_structp png_ptr, png_bytep row)
763 {
764 if (png_ptr == NULL)
765 return;
766 png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
767 png_ptr->row_number, png_ptr->pass);
769 /* initialize transformations and other stuff if first time */
770 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
771 {
772 /* make sure we wrote the header info */
773 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
774 png_error(png_ptr,
775 "png_write_info was never called before png_write_row.");
777 /* check for transforms that have been set but were defined out */
778 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
779 if (png_ptr->transformations & PNG_INVERT_MONO)
780 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
781 #endif
782 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
783 if (png_ptr->transformations & PNG_FILLER)
784 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
785 #endif
786 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
787 if (png_ptr->transformations & PNG_PACKSWAP)
788 png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
789 #endif
790 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
791 if (png_ptr->transformations & PNG_PACK)
792 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
793 #endif
794 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
795 if (png_ptr->transformations & PNG_SHIFT)
796 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
797 #endif
798 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
799 if (png_ptr->transformations & PNG_BGR)
800 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
801 #endif
802 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
803 if (png_ptr->transformations & PNG_SWAP_BYTES)
804 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
805 #endif
807 png_write_start_row(png_ptr);
808 }
810 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
811 /* if interlaced and not interested in row, return */
812 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
813 {
814 switch (png_ptr->pass)
815 {
816 case 0:
817 if (png_ptr->row_number & 0x07)
818 {
819 png_write_finish_row(png_ptr);
820 return;
821 }
822 break;
823 case 1:
824 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
825 {
826 png_write_finish_row(png_ptr);
827 return;
828 }
829 break;
830 case 2:
831 if ((png_ptr->row_number & 0x07) != 4)
832 {
833 png_write_finish_row(png_ptr);
834 return;
835 }
836 break;
837 case 3:
838 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
839 {
840 png_write_finish_row(png_ptr);
841 return;
842 }
843 break;
844 case 4:
845 if ((png_ptr->row_number & 0x03) != 2)
846 {
847 png_write_finish_row(png_ptr);
848 return;
849 }
850 break;
851 case 5:
852 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
853 {
854 png_write_finish_row(png_ptr);
855 return;
856 }
857 break;
858 case 6:
859 if (!(png_ptr->row_number & 0x01))
860 {
861 png_write_finish_row(png_ptr);
862 return;
863 }
864 break;
865 }
866 }
867 #endif
869 /* set up row info for transformations */
870 png_ptr->row_info.color_type = png_ptr->color_type;
871 png_ptr->row_info.width = png_ptr->usr_width;
872 png_ptr->row_info.channels = png_ptr->usr_channels;
873 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
874 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
875 png_ptr->row_info.channels);
877 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
878 png_ptr->row_info.width);
880 png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
881 png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
882 png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
883 png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
884 png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
885 png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
887 /* Copy user's row into buffer, leaving room for filter byte. */
888 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
889 png_ptr->row_info.rowbytes);
891 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
892 /* handle interlacing */
893 if (png_ptr->interlaced && png_ptr->pass < 6 &&
894 (png_ptr->transformations & PNG_INTERLACE))
895 {
896 png_do_write_interlace(&(png_ptr->row_info),
897 png_ptr->row_buf + 1, png_ptr->pass);
898 /* this should always get caught above, but still ... */
899 if (!(png_ptr->row_info.width))
900 {
901 png_write_finish_row(png_ptr);
902 return;
903 }
904 }
905 #endif
907 /* handle other transformations */
908 if (png_ptr->transformations)
909 png_do_write_transformations(png_ptr);
911 #if defined(PNG_MNG_FEATURES_SUPPORTED)
912 /* Write filter_method 64 (intrapixel differencing) only if
913 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
914 * 2. Libpng did not write a PNG signature (this filter_method is only
915 * used in PNG datastreams that are embedded in MNG datastreams) and
916 * 3. The application called png_permit_mng_features with a mask that
917 * included PNG_FLAG_MNG_FILTER_64 and
918 * 4. The filter_method is 64 and
919 * 5. The color_type is RGB or RGBA
920 */
921 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
922 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
923 {
924 /* Intrapixel differencing */
925 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
926 }
927 #endif
929 /* Find a filter if necessary, filter the row and write it out. */
930 png_write_find_filter(png_ptr, &(png_ptr->row_info));
932 if (png_ptr->write_row_fn != NULL)
933 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
934 }
936 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
937 /* Set the automatic flush interval or 0 to turn flushing off */
938 void PNGAPI
939 png_set_flush(png_structp png_ptr, int nrows)
940 {
941 png_debug(1, "in png_set_flush\n");
942 if (png_ptr == NULL)
943 return;
944 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
945 }
947 /* flush the current output buffers now */
948 void PNGAPI
949 png_write_flush(png_structp png_ptr)
950 {
951 int wrote_IDAT;
953 png_debug(1, "in png_write_flush\n");
954 if (png_ptr == NULL)
955 return;
956 /* We have already written out all of the data */
957 if (png_ptr->row_number >= png_ptr->num_rows)
958 return;
960 do
961 {
962 int ret;
964 /* compress the data */
965 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
966 wrote_IDAT = 0;
968 /* check for compression errors */
969 if (ret != Z_OK)
970 {
971 if (png_ptr->zstream.msg != NULL)
972 png_error(png_ptr, png_ptr->zstream.msg);
973 else
974 png_error(png_ptr, "zlib error");
975 }
977 if (!(png_ptr->zstream.avail_out))
978 {
979 /* write the IDAT and reset the zlib output buffer */
980 png_write_IDAT(png_ptr, png_ptr->zbuf,
981 png_ptr->zbuf_size);
982 png_ptr->zstream.next_out = png_ptr->zbuf;
983 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
984 wrote_IDAT = 1;
985 }
986 } while(wrote_IDAT == 1);
988 /* If there is any data left to be output, write it into a new IDAT */
989 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
990 {
991 /* write the IDAT and reset the zlib output buffer */
992 png_write_IDAT(png_ptr, png_ptr->zbuf,
993 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
994 png_ptr->zstream.next_out = png_ptr->zbuf;
995 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
996 }
997 png_ptr->flush_rows = 0;
998 png_flush(png_ptr);
999 }
1000 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
1002 /* free all memory used by the write */
1003 void PNGAPI
1004 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1005 {
1006 png_structp png_ptr = NULL;
1007 png_infop info_ptr = NULL;
1008 #ifdef PNG_USER_MEM_SUPPORTED
1009 png_free_ptr free_fn = NULL;
1010 png_voidp mem_ptr = NULL;
1011 #endif
1013 png_debug(1, "in png_destroy_write_struct\n");
1014 if (png_ptr_ptr != NULL)
1015 {
1016 png_ptr = *png_ptr_ptr;
1017 #ifdef PNG_USER_MEM_SUPPORTED
1018 free_fn = png_ptr->free_fn;
1019 mem_ptr = png_ptr->mem_ptr;
1020 #endif
1021 }
1023 #ifdef PNG_USER_MEM_SUPPORTED
1024 if (png_ptr != NULL)
1025 {
1026 free_fn = png_ptr->free_fn;
1027 mem_ptr = png_ptr->mem_ptr;
1028 }
1029 #endif
1031 if (info_ptr_ptr != NULL)
1032 info_ptr = *info_ptr_ptr;
1034 if (info_ptr != NULL)
1035 {
1036 if (png_ptr != NULL)
1037 {
1038 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1040 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1041 if (png_ptr->num_chunk_list)
1042 {
1043 png_free(png_ptr, png_ptr->chunk_list);
1044 png_ptr->chunk_list=NULL;
1045 png_ptr->num_chunk_list = 0;
1046 }
1047 #endif
1048 }
1050 #ifdef PNG_USER_MEM_SUPPORTED
1051 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1052 (png_voidp)mem_ptr);
1053 #else
1054 png_destroy_struct((png_voidp)info_ptr);
1055 #endif
1056 *info_ptr_ptr = NULL;
1057 }
1059 if (png_ptr != NULL)
1060 {
1061 png_write_destroy(png_ptr);
1062 #ifdef PNG_USER_MEM_SUPPORTED
1063 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1064 (png_voidp)mem_ptr);
1065 #else
1066 png_destroy_struct((png_voidp)png_ptr);
1067 #endif
1068 *png_ptr_ptr = NULL;
1069 }
1070 }
1073 /* Free any memory used in png_ptr struct (old method) */
1074 void /* PRIVATE */
1075 png_write_destroy(png_structp png_ptr)
1076 {
1077 #ifdef PNG_SETJMP_SUPPORTED
1078 jmp_buf tmp_jmp; /* save jump buffer */
1079 #endif
1080 png_error_ptr error_fn;
1081 png_error_ptr warning_fn;
1082 png_voidp error_ptr;
1083 #ifdef PNG_USER_MEM_SUPPORTED
1084 png_free_ptr free_fn;
1085 #endif
1087 png_debug(1, "in png_write_destroy\n");
1088 /* free any memory zlib uses */
1089 deflateEnd(&png_ptr->zstream);
1091 /* free our memory. png_free checks NULL for us. */
1092 png_free(png_ptr, png_ptr->zbuf);
1093 png_free(png_ptr, png_ptr->row_buf);
1094 #ifndef PNG_NO_WRITE_FILTER
1095 png_free(png_ptr, png_ptr->prev_row);
1096 png_free(png_ptr, png_ptr->sub_row);
1097 png_free(png_ptr, png_ptr->up_row);
1098 png_free(png_ptr, png_ptr->avg_row);
1099 png_free(png_ptr, png_ptr->paeth_row);
1100 #endif
1102 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1103 png_free(png_ptr, png_ptr->time_buffer);
1104 #endif
1106 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1107 png_free(png_ptr, png_ptr->prev_filters);
1108 png_free(png_ptr, png_ptr->filter_weights);
1109 png_free(png_ptr, png_ptr->inv_filter_weights);
1110 png_free(png_ptr, png_ptr->filter_costs);
1111 png_free(png_ptr, png_ptr->inv_filter_costs);
1112 #endif
1114 #ifdef PNG_SETJMP_SUPPORTED
1115 /* reset structure */
1116 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1117 #endif
1119 error_fn = png_ptr->error_fn;
1120 warning_fn = png_ptr->warning_fn;
1121 error_ptr = png_ptr->error_ptr;
1122 #ifdef PNG_USER_MEM_SUPPORTED
1123 free_fn = png_ptr->free_fn;
1124 #endif
1126 png_memset(png_ptr, 0, png_sizeof(png_struct));
1128 png_ptr->error_fn = error_fn;
1129 png_ptr->warning_fn = warning_fn;
1130 png_ptr->error_ptr = error_ptr;
1131 #ifdef PNG_USER_MEM_SUPPORTED
1132 png_ptr->free_fn = free_fn;
1133 #endif
1135 #ifdef PNG_SETJMP_SUPPORTED
1136 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1137 #endif
1138 }
1140 /* Allow the application to select one or more row filters to use. */
1141 void PNGAPI
1142 png_set_filter(png_structp png_ptr, int method, int filters)
1143 {
1144 png_debug(1, "in png_set_filter\n");
1145 if (png_ptr == NULL)
1146 return;
1147 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1148 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1149 (method == PNG_INTRAPIXEL_DIFFERENCING))
1150 method = PNG_FILTER_TYPE_BASE;
1151 #endif
1152 if (method == PNG_FILTER_TYPE_BASE)
1153 {
1154 switch (filters & (PNG_ALL_FILTERS | 0x07))
1155 {
1156 #ifndef PNG_NO_WRITE_FILTER
1157 case 5:
1158 case 6:
1159 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1160 #endif /* PNG_NO_WRITE_FILTER */
1161 case PNG_FILTER_VALUE_NONE:
1162 png_ptr->do_filter=PNG_FILTER_NONE; break;
1163 #ifndef PNG_NO_WRITE_FILTER
1164 case PNG_FILTER_VALUE_SUB:
1165 png_ptr->do_filter=PNG_FILTER_SUB; break;
1166 case PNG_FILTER_VALUE_UP:
1167 png_ptr->do_filter=PNG_FILTER_UP; break;
1168 case PNG_FILTER_VALUE_AVG:
1169 png_ptr->do_filter=PNG_FILTER_AVG; break;
1170 case PNG_FILTER_VALUE_PAETH:
1171 png_ptr->do_filter=PNG_FILTER_PAETH; break;
1172 default: png_ptr->do_filter = (png_byte)filters; break;
1173 #else
1174 default: png_warning(png_ptr, "Unknown row filter for method 0");
1175 #endif /* PNG_NO_WRITE_FILTER */
1176 }
1178 /* If we have allocated the row_buf, this means we have already started
1179 * with the image and we should have allocated all of the filter buffers
1180 * that have been selected. If prev_row isn't already allocated, then
1181 * it is too late to start using the filters that need it, since we
1182 * will be missing the data in the previous row. If an application
1183 * wants to start and stop using particular filters during compression,
1184 * it should start out with all of the filters, and then add and
1185 * remove them after the start of compression.
1186 */
1187 if (png_ptr->row_buf != NULL)
1188 {
1189 #ifndef PNG_NO_WRITE_FILTER
1190 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1191 {
1192 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1193 (png_ptr->rowbytes + 1));
1194 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1195 }
1197 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1198 {
1199 if (png_ptr->prev_row == NULL)
1200 {
1201 png_warning(png_ptr, "Can't add Up filter after starting");
1202 png_ptr->do_filter &= ~PNG_FILTER_UP;
1203 }
1204 else
1205 {
1206 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1207 (png_ptr->rowbytes + 1));
1208 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1209 }
1210 }
1212 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1213 {
1214 if (png_ptr->prev_row == NULL)
1215 {
1216 png_warning(png_ptr, "Can't add Average filter after starting");
1217 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1218 }
1219 else
1220 {
1221 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1222 (png_ptr->rowbytes + 1));
1223 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1224 }
1225 }
1227 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1228 png_ptr->paeth_row == NULL)
1229 {
1230 if (png_ptr->prev_row == NULL)
1231 {
1232 png_warning(png_ptr, "Can't add Paeth filter after starting");
1233 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1234 }
1235 else
1236 {
1237 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1238 (png_ptr->rowbytes + 1));
1239 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1240 }
1241 }
1243 if (png_ptr->do_filter == PNG_NO_FILTERS)
1244 #endif /* PNG_NO_WRITE_FILTER */
1245 png_ptr->do_filter = PNG_FILTER_NONE;
1246 }
1247 }
1248 else
1249 png_error(png_ptr, "Unknown custom filter method");
1250 }
1252 /* This allows us to influence the way in which libpng chooses the "best"
1253 * filter for the current scanline. While the "minimum-sum-of-absolute-
1254 * differences metric is relatively fast and effective, there is some
1255 * question as to whether it can be improved upon by trying to keep the
1256 * filtered data going to zlib more consistent, hopefully resulting in
1257 * better compression.
1258 */
1259 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1260 void PNGAPI
1261 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1262 int num_weights, png_doublep filter_weights,
1263 png_doublep filter_costs)
1264 {
1265 int i;
1267 png_debug(1, "in png_set_filter_heuristics\n");
1268 if (png_ptr == NULL)
1269 return;
1270 if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1271 {
1272 png_warning(png_ptr, "Unknown filter heuristic method");
1273 return;
1274 }
1276 if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1277 {
1278 heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1279 }
1281 if (num_weights < 0 || filter_weights == NULL ||
1282 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1283 {
1284 num_weights = 0;
1285 }
1287 png_ptr->num_prev_filters = (png_byte)num_weights;
1288 png_ptr->heuristic_method = (png_byte)heuristic_method;
1290 if (num_weights > 0)
1291 {
1292 if (png_ptr->prev_filters == NULL)
1293 {
1294 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1295 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1297 /* To make sure that the weighting starts out fairly */
1298 for (i = 0; i < num_weights; i++)
1299 {
1300 png_ptr->prev_filters[i] = 255;
1301 }
1302 }
1304 if (png_ptr->filter_weights == NULL)
1305 {
1306 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1307 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1309 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1310 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1311 for (i = 0; i < num_weights; i++)
1312 {
1313 png_ptr->inv_filter_weights[i] =
1314 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1315 }
1316 }
1318 for (i = 0; i < num_weights; i++)
1319 {
1320 if (filter_weights[i] < 0.0)
1321 {
1322 png_ptr->inv_filter_weights[i] =
1323 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1324 }
1325 else
1326 {
1327 png_ptr->inv_filter_weights[i] =
1328 (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1329 png_ptr->filter_weights[i] =
1330 (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1331 }
1332 }
1333 }
1335 /* If, in the future, there are other filter methods, this would
1336 * need to be based on png_ptr->filter.
1337 */
1338 if (png_ptr->filter_costs == NULL)
1339 {
1340 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1341 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1343 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1344 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1346 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1347 {
1348 png_ptr->inv_filter_costs[i] =
1349 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1350 }
1351 }
1353 /* Here is where we set the relative costs of the different filters. We
1354 * should take the desired compression level into account when setting
1355 * the costs, so that Paeth, for instance, has a high relative cost at low
1356 * compression levels, while it has a lower relative cost at higher
1357 * compression settings. The filter types are in order of increasing
1358 * relative cost, so it would be possible to do this with an algorithm.
1359 */
1360 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1361 {
1362 if (filter_costs == NULL || filter_costs[i] < 0.0)
1363 {
1364 png_ptr->inv_filter_costs[i] =
1365 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1366 }
1367 else if (filter_costs[i] >= 1.0)
1368 {
1369 png_ptr->inv_filter_costs[i] =
1370 (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1371 png_ptr->filter_costs[i] =
1372 (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1373 }
1374 }
1375 }
1376 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1378 void PNGAPI
1379 png_set_compression_level(png_structp png_ptr, int level)
1380 {
1381 png_debug(1, "in png_set_compression_level\n");
1382 if (png_ptr == NULL)
1383 return;
1384 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1385 png_ptr->zlib_level = level;
1386 }
1388 void PNGAPI
1389 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1390 {
1391 png_debug(1, "in png_set_compression_mem_level\n");
1392 if (png_ptr == NULL)
1393 return;
1394 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1395 png_ptr->zlib_mem_level = mem_level;
1396 }
1398 void PNGAPI
1399 png_set_compression_strategy(png_structp png_ptr, int strategy)
1400 {
1401 png_debug(1, "in png_set_compression_strategy\n");
1402 if (png_ptr == NULL)
1403 return;
1404 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1405 png_ptr->zlib_strategy = strategy;
1406 }
1408 void PNGAPI
1409 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1410 {
1411 if (png_ptr == NULL)
1412 return;
1413 if (window_bits > 15)
1414 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1415 else if (window_bits < 8)
1416 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1417 #ifndef WBITS_8_OK
1418 /* avoid libpng bug with 256-byte windows */
1419 if (window_bits == 8)
1420 {
1421 png_warning(png_ptr, "Compression window is being reset to 512");
1422 window_bits=9;
1423 }
1424 #endif
1425 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1426 png_ptr->zlib_window_bits = window_bits;
1427 }
1429 void PNGAPI
1430 png_set_compression_method(png_structp png_ptr, int method)
1431 {
1432 png_debug(1, "in png_set_compression_method\n");
1433 if (png_ptr == NULL)
1434 return;
1435 if (method != 8)
1436 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1437 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1438 png_ptr->zlib_method = method;
1439 }
1441 void PNGAPI
1442 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1443 {
1444 if (png_ptr == NULL)
1445 return;
1446 png_ptr->write_row_fn = write_row_fn;
1447 }
1449 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1450 void PNGAPI
1451 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1452 write_user_transform_fn)
1453 {
1454 png_debug(1, "in png_set_write_user_transform_fn\n");
1455 if (png_ptr == NULL)
1456 return;
1457 png_ptr->transformations |= PNG_USER_TRANSFORM;
1458 png_ptr->write_user_transform_fn = write_user_transform_fn;
1459 }
1460 #endif
1463 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1464 void PNGAPI
1465 png_write_png(png_structp png_ptr, png_infop info_ptr,
1466 int transforms, voidp params)
1467 {
1468 if (png_ptr == NULL || info_ptr == NULL)
1469 return;
1470 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1471 /* invert the alpha channel from opacity to transparency */
1472 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1473 png_set_invert_alpha(png_ptr);
1474 #endif
1476 /* Write the file header information. */
1477 png_write_info(png_ptr, info_ptr);
1479 /* ------ these transformations don't touch the info structure ------- */
1481 #if defined(PNG_WRITE_INVERT_SUPPORTED)
1482 /* invert monochrome pixels */
1483 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1484 png_set_invert_mono(png_ptr);
1485 #endif
1487 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
1488 /* Shift the pixels up to a legal bit depth and fill in
1489 * as appropriate to correctly scale the image.
1490 */
1491 if ((transforms & PNG_TRANSFORM_SHIFT)
1492 && (info_ptr->valid & PNG_INFO_sBIT))
1493 png_set_shift(png_ptr, &info_ptr->sig_bit);
1494 #endif
1496 #if defined(PNG_WRITE_PACK_SUPPORTED)
1497 /* pack pixels into bytes */
1498 if (transforms & PNG_TRANSFORM_PACKING)
1499 png_set_packing(png_ptr);
1500 #endif
1502 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1503 /* swap location of alpha bytes from ARGB to RGBA */
1504 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1505 png_set_swap_alpha(png_ptr);
1506 #endif
1508 #if defined(PNG_WRITE_FILLER_SUPPORTED)
1509 /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1510 * RGB (4 channels -> 3 channels). The second parameter is not used.
1511 */
1512 if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1513 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1514 #endif
1516 #if defined(PNG_WRITE_BGR_SUPPORTED)
1517 /* flip BGR pixels to RGB */
1518 if (transforms & PNG_TRANSFORM_BGR)
1519 png_set_bgr(png_ptr);
1520 #endif
1522 #if defined(PNG_WRITE_SWAP_SUPPORTED)
1523 /* swap bytes of 16-bit files to most significant byte first */
1524 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1525 png_set_swap(png_ptr);
1526 #endif
1528 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1529 /* swap bits of 1, 2, 4 bit packed pixel formats */
1530 if (transforms & PNG_TRANSFORM_PACKSWAP)
1531 png_set_packswap(png_ptr);
1532 #endif
1534 /* ----------------------- end of transformations ------------------- */
1536 /* write the bits */
1537 if (info_ptr->valid & PNG_INFO_IDAT)
1538 png_write_image(png_ptr, info_ptr->row_pointers);
1540 /* It is REQUIRED to call this to finish writing the rest of the file */
1541 png_write_end(png_ptr, info_ptr);
1543 transforms = transforms; /* quiet compiler warnings */
1544 params = params;
1545 }
1546 #endif
1547 #endif /* PNG_WRITE_SUPPORTED */