1
2 /* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.5.11 [June 14, 2012]
5 * Copyright (c) 1998-2012 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14 #include "pngpriv.h"
15
16 #ifdef PNG_WRITE_SUPPORTED
17
18 /* Writes all the PNG information. This is the suggested way to use the
19 * library. If you have a new chunk to add, make a function to write it,
20 * and put it in the correct location here. If you want the chunk written
21 * after the image data, put it in png_write_end(). I strongly encourage
22 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
23 * the chunk, as that will keep the code from breaking if you want to just
24 * write a plain PNG file. If you have long comments, I suggest writing
25 * them in png_write_end(), and compressing them.
26 */
27 void PNGAPI
png_write_info_before_PLTE(png_structp png_ptr,png_infop info_ptr)28 png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
29 {
30 png_debug(1, "in png_write_info_before_PLTE");
31
32 if (png_ptr == NULL || info_ptr == NULL)
33 return;
34
35 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
36 {
37 /* Write PNG signature */
38 png_write_sig(png_ptr);
39
40 #ifdef PNG_MNG_FEATURES_SUPPORTED
41 if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
42 (png_ptr->mng_features_permitted))
43 {
44 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
45 png_ptr->mng_features_permitted = 0;
46 }
47 #endif
48
49 /* Write IHDR information. */
50 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
51 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
52 info_ptr->filter_type,
53 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
54 info_ptr->interlace_type);
55 #else
56 0);
57 #endif
58 /* The rest of these check to see if the valid field has the appropriate
59 * flag set, and if it does, writes the chunk.
60 */
61 #ifdef PNG_WRITE_gAMA_SUPPORTED
62 if (info_ptr->valid & PNG_INFO_gAMA)
63 png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
64 #endif
65 #ifdef PNG_WRITE_sRGB_SUPPORTED
66 if (info_ptr->valid & PNG_INFO_sRGB)
67 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
68 #endif
69
70 #ifdef PNG_WRITE_iCCP_SUPPORTED
71 if (info_ptr->valid & PNG_INFO_iCCP)
72 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
73 (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
74 #endif
75 #ifdef PNG_WRITE_sBIT_SUPPORTED
76 if (info_ptr->valid & PNG_INFO_sBIT)
77 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
78 #endif
79 #ifdef PNG_WRITE_cHRM_SUPPORTED
80 if (info_ptr->valid & PNG_INFO_cHRM)
81 png_write_cHRM_fixed(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 #endif
87
88 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
89 if (info_ptr->unknown_chunks_num)
90 {
91 png_unknown_chunk *up;
92
93 png_debug(5, "writing extra chunks");
94
95 for (up = info_ptr->unknown_chunks;
96 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
97 up++)
98 {
99 int keep = png_handle_as_unknown(png_ptr, up->name);
100
101 if (keep != PNG_HANDLE_CHUNK_NEVER &&
102 up->location &&
103 !(up->location & PNG_HAVE_PLTE) &&
104 !(up->location & PNG_HAVE_IDAT) &&
105 !(up->location & PNG_AFTER_IDAT) &&
106 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
107 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
108 {
109 if (up->size == 0)
110 png_warning(png_ptr, "Writing zero-length unknown chunk");
111
112 png_write_chunk(png_ptr, up->name, up->data, up->size);
113 }
114 }
115 }
116 #endif
117 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
118 }
119 }
120
121 void PNGAPI
png_write_info(png_structp png_ptr,png_infop info_ptr)122 png_write_info(png_structp png_ptr, png_infop info_ptr)
123 {
124 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
125 int i;
126 #endif
127
128 png_debug(1, "in png_write_info");
129
130 if (png_ptr == NULL || info_ptr == NULL)
131 return;
132
133 png_write_info_before_PLTE(png_ptr, info_ptr);
134
135 if (info_ptr->valid & PNG_INFO_PLTE)
136 png_write_PLTE(png_ptr, info_ptr->palette,
137 (png_uint_32)info_ptr->num_palette);
138
139 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
140 png_error(png_ptr, "Valid palette required for paletted images");
141
142 #ifdef PNG_WRITE_tRNS_SUPPORTED
143 if (info_ptr->valid & PNG_INFO_tRNS)
144 {
145 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
146 /* Invert the alpha channel (in tRNS) */
147 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
148 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
149 {
150 int j;
151 for (j = 0; j<(int)info_ptr->num_trans; j++)
152 info_ptr->trans_alpha[j] =
153 (png_byte)(255 - info_ptr->trans_alpha[j]);
154 }
155 #endif
156 png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
157 info_ptr->num_trans, info_ptr->color_type);
158 }
159 #endif
160 #ifdef PNG_WRITE_bKGD_SUPPORTED
161 if (info_ptr->valid & PNG_INFO_bKGD)
162 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
163 #endif
164
165 #ifdef PNG_WRITE_hIST_SUPPORTED
166 if (info_ptr->valid & PNG_INFO_hIST)
167 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
168 #endif
169
170 #ifdef PNG_WRITE_oFFs_SUPPORTED
171 if (info_ptr->valid & PNG_INFO_oFFs)
172 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
173 info_ptr->offset_unit_type);
174 #endif
175
176 #ifdef 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
183 #ifdef PNG_WRITE_sCAL_SUPPORTED
184 if (info_ptr->valid & PNG_INFO_sCAL)
185 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
186 info_ptr->scal_s_width, info_ptr->scal_s_height);
187 #endif /* sCAL */
188
189 #ifdef PNG_WRITE_pHYs_SUPPORTED
190 if (info_ptr->valid & PNG_INFO_pHYs)
191 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
192 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
193 #endif /* pHYs */
194
195 #ifdef PNG_WRITE_tIME_SUPPORTED
196 if (info_ptr->valid & PNG_INFO_tIME)
197 {
198 png_write_tIME(png_ptr, &(info_ptr->mod_time));
199 png_ptr->mode |= PNG_WROTE_tIME;
200 }
201 #endif /* tIME */
202
203 #ifdef PNG_WRITE_sPLT_SUPPORTED
204 if (info_ptr->valid & PNG_INFO_sPLT)
205 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
206 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
207 #endif /* sPLT */
208
209 #ifdef PNG_WRITE_TEXT_SUPPORTED
210 /* Check to see if we need to write text chunks */
211 for (i = 0; i < info_ptr->num_text; i++)
212 {
213 png_debug2(2, "Writing header text chunk %d, type %d", i,
214 info_ptr->text[i].compression);
215 /* An internationalized chunk? */
216 if (info_ptr->text[i].compression > 0)
217 {
218 #ifdef PNG_WRITE_iTXt_SUPPORTED
219 /* Write international chunk */
220 png_write_iTXt(png_ptr,
221 info_ptr->text[i].compression,
222 info_ptr->text[i].key,
223 info_ptr->text[i].lang,
224 info_ptr->text[i].lang_key,
225 info_ptr->text[i].text);
226 #else
227 png_warning(png_ptr, "Unable to write international text");
228 #endif
229 /* Mark this chunk as written */
230 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
231 }
232
233 /* If we want a compressed text chunk */
234 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
235 {
236 #ifdef PNG_WRITE_zTXt_SUPPORTED
237 /* Write compressed chunk */
238 png_write_zTXt(png_ptr, info_ptr->text[i].key,
239 info_ptr->text[i].text, 0,
240 info_ptr->text[i].compression);
241 #else
242 png_warning(png_ptr, "Unable to write compressed text");
243 #endif
244 /* Mark this chunk as written */
245 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
246 }
247
248 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
249 {
250 #ifdef PNG_WRITE_tEXt_SUPPORTED
251 /* Write uncompressed chunk */
252 png_write_tEXt(png_ptr, info_ptr->text[i].key,
253 info_ptr->text[i].text,
254 0);
255 /* Mark this chunk as written */
256 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
257 #else
258 /* Can't get here */
259 png_warning(png_ptr, "Unable to write uncompressed text");
260 #endif
261 }
262 }
263 #endif /* tEXt */
264
265 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
266 if (info_ptr->unknown_chunks_num)
267 {
268 png_unknown_chunk *up;
269
270 png_debug(5, "writing extra chunks");
271
272 for (up = info_ptr->unknown_chunks;
273 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
274 up++)
275 {
276 int keep = png_handle_as_unknown(png_ptr, up->name);
277 if (keep != PNG_HANDLE_CHUNK_NEVER &&
278 up->location &&
279 (up->location & PNG_HAVE_PLTE) &&
280 !(up->location & PNG_HAVE_IDAT) &&
281 !(up->location & PNG_AFTER_IDAT) &&
282 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
283 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
284 {
285 png_write_chunk(png_ptr, up->name, up->data, up->size);
286 }
287 }
288 }
289 #endif
290 }
291
292 /* Writes the end of the PNG file. If you don't want to write comments or
293 * time information, you can pass NULL for info. If you already wrote these
294 * in png_write_info(), do not write them again here. If you have long
295 * comments, I suggest writing them here, and compressing them.
296 */
297 void PNGAPI
png_write_end(png_structp png_ptr,png_infop info_ptr)298 png_write_end(png_structp png_ptr, png_infop info_ptr)
299 {
300 png_debug(1, "in png_write_end");
301
302 if (png_ptr == NULL)
303 return;
304
305 if (!(png_ptr->mode & PNG_HAVE_IDAT))
306 png_error(png_ptr, "No IDATs written into file");
307
308 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
309 if (png_ptr->num_palette_max > png_ptr->num_palette)
310 png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
311 #endif
312
313 /* See if user wants us to write information chunks */
314 if (info_ptr != NULL)
315 {
316 #ifdef PNG_WRITE_TEXT_SUPPORTED
317 int i; /* local index variable */
318 #endif
319 #ifdef PNG_WRITE_tIME_SUPPORTED
320 /* Check to see if user has supplied a time chunk */
321 if ((info_ptr->valid & PNG_INFO_tIME) &&
322 !(png_ptr->mode & PNG_WROTE_tIME))
323 png_write_tIME(png_ptr, &(info_ptr->mod_time));
324
325 #endif
326 #ifdef PNG_WRITE_TEXT_SUPPORTED
327 /* Loop through comment chunks */
328 for (i = 0; i < info_ptr->num_text; i++)
329 {
330 png_debug2(2, "Writing trailer text chunk %d, type %d", i,
331 info_ptr->text[i].compression);
332 /* An internationalized chunk? */
333 if (info_ptr->text[i].compression > 0)
334 {
335 #ifdef PNG_WRITE_iTXt_SUPPORTED
336 /* Write international chunk */
337 png_write_iTXt(png_ptr,
338 info_ptr->text[i].compression,
339 info_ptr->text[i].key,
340 info_ptr->text[i].lang,
341 info_ptr->text[i].lang_key,
342 info_ptr->text[i].text);
343 #else
344 png_warning(png_ptr, "Unable to write international text");
345 #endif
346 /* Mark this chunk as written */
347 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
348 }
349
350 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
351 {
352 #ifdef PNG_WRITE_zTXt_SUPPORTED
353 /* Write compressed chunk */
354 png_write_zTXt(png_ptr, info_ptr->text[i].key,
355 info_ptr->text[i].text, 0,
356 info_ptr->text[i].compression);
357 #else
358 png_warning(png_ptr, "Unable to write compressed text");
359 #endif
360 /* Mark this chunk as written */
361 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
362 }
363
364 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
365 {
366 #ifdef PNG_WRITE_tEXt_SUPPORTED
367 /* Write uncompressed chunk */
368 png_write_tEXt(png_ptr, info_ptr->text[i].key,
369 info_ptr->text[i].text, 0);
370 #else
371 png_warning(png_ptr, "Unable to write uncompressed text");
372 #endif
373
374 /* Mark this chunk as written */
375 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
376 }
377 }
378 #endif
379 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
380 if (info_ptr->unknown_chunks_num)
381 {
382 png_unknown_chunk *up;
383
384 png_debug(5, "writing extra chunks");
385
386 for (up = info_ptr->unknown_chunks;
387 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
388 up++)
389 {
390 int keep = png_handle_as_unknown(png_ptr, up->name);
391 if (keep != PNG_HANDLE_CHUNK_NEVER &&
392 up->location &&
393 (up->location & PNG_AFTER_IDAT) &&
394 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
395 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
396 {
397 png_write_chunk(png_ptr, up->name, up->data, up->size);
398 }
399 }
400 }
401 #endif
402 }
403
404 png_ptr->mode |= PNG_AFTER_IDAT;
405
406 /* Write end of PNG file */
407 png_write_IEND(png_ptr);
408 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
409 * and restored again in libpng-1.2.30, may cause some applications that
410 * do not set png_ptr->output_flush_fn to crash. If your application
411 * experiences a problem, please try building libpng with
412 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
413 * png-mng-implement at lists.sf.net .
414 */
415 #ifdef PNG_WRITE_FLUSH_SUPPORTED
416 # ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
417 png_flush(png_ptr);
418 # endif
419 #endif
420 }
421
422 #ifdef PNG_CONVERT_tIME_SUPPORTED
423 /* "tm" structure is not supported on WindowsCE */
424 void PNGAPI
png_convert_from_struct_tm(png_timep ptime,PNG_CONST struct tm FAR * ttime)425 png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime)
426 {
427 png_debug(1, "in png_convert_from_struct_tm");
428
429 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
430 ptime->month = (png_byte)(ttime->tm_mon + 1);
431 ptime->day = (png_byte)ttime->tm_mday;
432 ptime->hour = (png_byte)ttime->tm_hour;
433 ptime->minute = (png_byte)ttime->tm_min;
434 ptime->second = (png_byte)ttime->tm_sec;
435 }
436
437 void PNGAPI
png_convert_from_time_t(png_timep ptime,time_t ttime)438 png_convert_from_time_t(png_timep ptime, time_t ttime)
439 {
440 struct tm *tbuf;
441
442 png_debug(1, "in png_convert_from_time_t");
443
444 tbuf = gmtime(&ttime);
445 png_convert_from_struct_tm(ptime, tbuf);
446 }
447 #endif
448
449 /* Initialize png_ptr structure, and allocate any memory needed */
450 PNG_FUNCTION(png_structp,PNGAPI
451 png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
452 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
453 {
454 #ifdef PNG_USER_MEM_SUPPORTED
455 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
456 warn_fn, NULL, NULL, NULL));
457 }
458
459 /* Alternate initialize png_ptr structure, and allocate any memory needed */
460 static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
461
462 PNG_FUNCTION(png_structp,PNGAPI
463 png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
464 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
465 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
466 {
467 #endif /* PNG_USER_MEM_SUPPORTED */
468 volatile int png_cleanup_needed = 0;
469 #ifdef PNG_SETJMP_SUPPORTED
470 volatile
471 #endif
472 png_structp png_ptr;
473 #ifdef PNG_SETJMP_SUPPORTED
474 #ifdef USE_FAR_KEYWORD
475 jmp_buf tmp_jmpbuf;
476 #endif
477 #endif
478
479 png_debug(1, "in png_create_write_struct");
480
481 #ifdef PNG_USER_MEM_SUPPORTED
482 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
483 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
484 #else
485 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
486 #endif /* PNG_USER_MEM_SUPPORTED */
487 if (png_ptr == NULL)
488 return (NULL);
489
490 /* Added at libpng-1.2.6 */
491 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
492 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
493 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
494 #endif
495
496 #ifdef PNG_SETJMP_SUPPORTED
497 /* Applications that neglect to set up their own setjmp() and then
498 * encounter a png_error() will longjmp here. Since the jmpbuf is
499 * then meaningless we abort instead of returning.
500 */
501 #ifdef USE_FAR_KEYWORD
502 if (setjmp(tmp_jmpbuf))
503 #else
504 if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
505 #endif
506 #ifdef USE_FAR_KEYWORD
507 png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
508 #endif
509 PNG_ABORT();
510 #endif
511
512 #ifdef PNG_USER_MEM_SUPPORTED
513 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
514 #endif /* PNG_USER_MEM_SUPPORTED */
515 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
516
517 if (!png_user_version_check(png_ptr, user_png_ver))
518 png_cleanup_needed = 1;
519
520 /* Initialize zbuf - compression buffer */
521 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
522
523 if (!png_cleanup_needed)
524 {
525 png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
526 png_ptr->zbuf_size);
527 if (png_ptr->zbuf == NULL)
528 png_cleanup_needed = 1;
529 }
530
531 if (png_cleanup_needed)
532 {
533 /* Clean up PNG structure and deallocate any memory. */
534 png_free(png_ptr, png_ptr->zbuf);
535 png_ptr->zbuf = NULL;
536 #ifdef PNG_USER_MEM_SUPPORTED
537 png_destroy_struct_2((png_voidp)png_ptr,
538 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
539 #else
540 png_destroy_struct((png_voidp)png_ptr);
541 #endif
542 return (NULL);
543 }
544
545 png_set_write_fn(png_ptr, NULL, NULL, NULL);
546
547 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
548 png_reset_filter_heuristics(png_ptr);
549 #endif
550
551 return (png_ptr);
552 }
553
554
555 /* Write a few rows of image data. If the image is interlaced,
556 * either you will have to write the 7 sub images, or, if you
557 * have called png_set_interlace_handling(), you will have to
558 * "write" the image seven times.
559 */
560 void PNGAPI
png_write_rows(png_structp png_ptr,png_bytepp row,png_uint_32 num_rows)561 png_write_rows(png_structp png_ptr, png_bytepp row,
562 png_uint_32 num_rows)
563 {
564 png_uint_32 i; /* row counter */
565 png_bytepp rp; /* row pointer */
566
567 png_debug(1, "in png_write_rows");
568
569 if (png_ptr == NULL)
570 return;
571
572 /* Loop through the rows */
573 for (i = 0, rp = row; i < num_rows; i++, rp++)
574 {
575 png_write_row(png_ptr, *rp);
576 }
577 }
578
579 /* Write the image. You only need to call this function once, even
580 * if you are writing an interlaced image.
581 */
582 void PNGAPI
png_write_image(png_structp png_ptr,png_bytepp image)583 png_write_image(png_structp png_ptr, png_bytepp image)
584 {
585 png_uint_32 i; /* row index */
586 int pass, num_pass; /* pass variables */
587 png_bytepp rp; /* points to current row */
588
589 if (png_ptr == NULL)
590 return;
591
592 png_debug(1, "in png_write_image");
593
594 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
595 /* Initialize interlace handling. If image is not interlaced,
596 * this will set pass to 1
597 */
598 num_pass = png_set_interlace_handling(png_ptr);
599 #else
600 num_pass = 1;
601 #endif
602 /* Loop through passes */
603 for (pass = 0; pass < num_pass; pass++)
604 {
605 /* Loop through image */
606 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
607 {
608 png_write_row(png_ptr, *rp);
609 }
610 }
611 }
612
613 /* Called by user to write a row of image data */
614 void PNGAPI
png_write_row(png_structp png_ptr,png_const_bytep row)615 png_write_row(png_structp png_ptr, png_const_bytep row)
616 {
617 /* 1.5.6: moved from png_struct to be a local structure: */
618 png_row_info row_info;
619
620 if (png_ptr == NULL)
621 return;
622
623 png_debug2(1, "in png_write_row (row %u, pass %d)",
624 png_ptr->row_number, png_ptr->pass);
625
626 /* Initialize transformations and other stuff if first time */
627 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
628 {
629 /* Make sure we wrote the header info */
630 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
631 png_error(png_ptr,
632 "png_write_info was never called before png_write_row");
633
634 /* Check for transforms that have been set but were defined out */
635 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
636 if (png_ptr->transformations & PNG_INVERT_MONO)
637 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
638 #endif
639
640 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
641 if (png_ptr->transformations & PNG_FILLER)
642 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
643 #endif
644 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
645 defined(PNG_READ_PACKSWAP_SUPPORTED)
646 if (png_ptr->transformations & PNG_PACKSWAP)
647 png_warning(png_ptr,
648 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
649 #endif
650
651 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
652 if (png_ptr->transformations & PNG_PACK)
653 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
654 #endif
655
656 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
657 if (png_ptr->transformations & PNG_SHIFT)
658 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
659 #endif
660
661 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
662 if (png_ptr->transformations & PNG_BGR)
663 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
664 #endif
665
666 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
667 if (png_ptr->transformations & PNG_SWAP_BYTES)
668 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
669 #endif
670
671 png_write_start_row(png_ptr);
672 }
673
674 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
675 /* If interlaced and not interested in row, return */
676 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
677 {
678 switch (png_ptr->pass)
679 {
680 case 0:
681 if (png_ptr->row_number & 0x07)
682 {
683 png_write_finish_row(png_ptr);
684 return;
685 }
686 break;
687
688 case 1:
689 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
690 {
691 png_write_finish_row(png_ptr);
692 return;
693 }
694 break;
695
696 case 2:
697 if ((png_ptr->row_number & 0x07) != 4)
698 {
699 png_write_finish_row(png_ptr);
700 return;
701 }
702 break;
703
704 case 3:
705 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
706 {
707 png_write_finish_row(png_ptr);
708 return;
709 }
710 break;
711
712 case 4:
713 if ((png_ptr->row_number & 0x03) != 2)
714 {
715 png_write_finish_row(png_ptr);
716 return;
717 }
718 break;
719
720 case 5:
721 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
722 {
723 png_write_finish_row(png_ptr);
724 return;
725 }
726 break;
727
728 case 6:
729 if (!(png_ptr->row_number & 0x01))
730 {
731 png_write_finish_row(png_ptr);
732 return;
733 }
734 break;
735
736 default: /* error: ignore it */
737 break;
738 }
739 }
740 #endif
741
742 /* Set up row info for transformations */
743 row_info.color_type = png_ptr->color_type;
744 row_info.width = png_ptr->usr_width;
745 row_info.channels = png_ptr->usr_channels;
746 row_info.bit_depth = png_ptr->usr_bit_depth;
747 row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
748 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
749
750 png_debug1(3, "row_info->color_type = %d", row_info.color_type);
751 png_debug1(3, "row_info->width = %u", row_info.width);
752 png_debug1(3, "row_info->channels = %d", row_info.channels);
753 png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
754 png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
755 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
756
757 /* Copy user's row into buffer, leaving room for filter byte. */
758 png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
759
760 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
761 /* Handle interlacing */
762 if (png_ptr->interlaced && png_ptr->pass < 6 &&
763 (png_ptr->transformations & PNG_INTERLACE))
764 {
765 png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
766 /* This should always get caught above, but still ... */
767 if (!(row_info.width))
768 {
769 png_write_finish_row(png_ptr);
770 return;
771 }
772 }
773 #endif
774
775 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
776 /* Handle other transformations */
777 if (png_ptr->transformations)
778 png_do_write_transformations(png_ptr, &row_info);
779 #endif
780
781 /* At this point the row_info pixel depth must match the 'transformed' depth,
782 * which is also the output depth.
783 */
784 if (row_info.pixel_depth != png_ptr->pixel_depth ||
785 row_info.pixel_depth != png_ptr->transformed_pixel_depth)
786 png_error(png_ptr, "internal write transform logic error");
787
788 #ifdef PNG_MNG_FEATURES_SUPPORTED
789 /* Write filter_method 64 (intrapixel differencing) only if
790 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
791 * 2. Libpng did not write a PNG signature (this filter_method is only
792 * used in PNG datastreams that are embedded in MNG datastreams) and
793 * 3. The application called png_permit_mng_features with a mask that
794 * included PNG_FLAG_MNG_FILTER_64 and
795 * 4. The filter_method is 64 and
796 * 5. The color_type is RGB or RGBA
797 */
798 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
799 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
800 {
801 /* Intrapixel differencing */
802 png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
803 }
804 #endif
805
806 /* Added at libpng-1.5.10 */
807 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
808 /* Check for out-of-range palette index */
809 if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
810 png_ptr->num_palette_max >= 0)
811 png_do_check_palette_indexes(png_ptr, &row_info);
812 #endif
813
814 /* Find a filter if necessary, filter the row and write it out. */
815 png_write_find_filter(png_ptr, &row_info);
816
817 if (png_ptr->write_row_fn != NULL)
818 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
819 }
820
821 #ifdef PNG_WRITE_FLUSH_SUPPORTED
822 /* Set the automatic flush interval or 0 to turn flushing off */
823 void PNGAPI
png_set_flush(png_structp png_ptr,int nrows)824 png_set_flush(png_structp png_ptr, int nrows)
825 {
826 png_debug(1, "in png_set_flush");
827
828 if (png_ptr == NULL)
829 return;
830
831 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
832 }
833
834 /* Flush the current output buffers now */
835 void PNGAPI
png_write_flush(png_structp png_ptr)836 png_write_flush(png_structp png_ptr)
837 {
838 int wrote_IDAT;
839
840 png_debug(1, "in png_write_flush");
841
842 if (png_ptr == NULL)
843 return;
844
845 /* We have already written out all of the data */
846 if (png_ptr->row_number >= png_ptr->num_rows)
847 return;
848
849 do
850 {
851 int ret;
852
853 /* Compress the data */
854 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
855 wrote_IDAT = 0;
856
857 /* Check for compression errors */
858 if (ret != Z_OK)
859 {
860 if (png_ptr->zstream.msg != NULL)
861 png_error(png_ptr, png_ptr->zstream.msg);
862
863 else
864 png_error(png_ptr, "zlib error");
865 }
866
867 if (!(png_ptr->zstream.avail_out))
868 {
869 /* Write the IDAT and reset the zlib output buffer */
870 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
871 wrote_IDAT = 1;
872 }
873 } while (wrote_IDAT == 1);
874
875 /* If there is any data left to be output, write it into a new IDAT */
876 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
877 {
878 /* Write the IDAT and reset the zlib output buffer */
879 png_write_IDAT(png_ptr, png_ptr->zbuf,
880 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
881 }
882 png_ptr->flush_rows = 0;
883 png_flush(png_ptr);
884 }
885 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
886
887 /* Free all memory used by the write */
888 void PNGAPI
png_destroy_write_struct(png_structpp png_ptr_ptr,png_infopp info_ptr_ptr)889 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
890 {
891 png_structp png_ptr = NULL;
892 png_infop info_ptr = NULL;
893 #ifdef PNG_USER_MEM_SUPPORTED
894 png_free_ptr free_fn = NULL;
895 png_voidp mem_ptr = NULL;
896 #endif
897
898 png_debug(1, "in png_destroy_write_struct");
899
900 if (png_ptr_ptr != NULL)
901 png_ptr = *png_ptr_ptr;
902
903 #ifdef PNG_USER_MEM_SUPPORTED
904 if (png_ptr != NULL)
905 {
906 free_fn = png_ptr->free_fn;
907 mem_ptr = png_ptr->mem_ptr;
908 }
909 #endif
910
911 if (info_ptr_ptr != NULL)
912 info_ptr = *info_ptr_ptr;
913
914 if (info_ptr != NULL)
915 {
916 if (png_ptr != NULL)
917 {
918 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
919
920 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
921 if (png_ptr->num_chunk_list)
922 {
923 png_free(png_ptr, png_ptr->chunk_list);
924 png_ptr->num_chunk_list = 0;
925 }
926 #endif
927 }
928
929 #ifdef PNG_USER_MEM_SUPPORTED
930 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
931 (png_voidp)mem_ptr);
932 #else
933 png_destroy_struct((png_voidp)info_ptr);
934 #endif
935 *info_ptr_ptr = NULL;
936 }
937
938 if (png_ptr != NULL)
939 {
940 png_write_destroy(png_ptr);
941 #ifdef PNG_USER_MEM_SUPPORTED
942 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
943 (png_voidp)mem_ptr);
944 #else
945 png_destroy_struct((png_voidp)png_ptr);
946 #endif
947 *png_ptr_ptr = NULL;
948 }
949 }
950
951
952 /* Free any memory used in png_ptr struct (old method) */
953 void /* PRIVATE */
png_write_destroy(png_structp png_ptr)954 png_write_destroy(png_structp png_ptr)
955 {
956 #ifdef PNG_SETJMP_SUPPORTED
957 jmp_buf tmp_jmp; /* Save jump buffer */
958 #endif
959 png_error_ptr error_fn;
960 #ifdef PNG_WARNINGS_SUPPORTED
961 png_error_ptr warning_fn;
962 #endif
963 png_voidp error_ptr;
964 #ifdef PNG_USER_MEM_SUPPORTED
965 png_free_ptr free_fn;
966 #endif
967
968 png_debug(1, "in png_write_destroy");
969
970 /* Free any memory zlib uses */
971 if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
972 deflateEnd(&png_ptr->zstream);
973
974 /* Free our memory. png_free checks NULL for us. */
975 png_free(png_ptr, png_ptr->zbuf);
976 png_free(png_ptr, png_ptr->row_buf);
977 #ifdef PNG_WRITE_FILTER_SUPPORTED
978 png_free(png_ptr, png_ptr->prev_row);
979 png_free(png_ptr, png_ptr->sub_row);
980 png_free(png_ptr, png_ptr->up_row);
981 png_free(png_ptr, png_ptr->avg_row);
982 png_free(png_ptr, png_ptr->paeth_row);
983 #endif
984
985 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
986 /* Use this to save a little code space, it doesn't free the filter_costs */
987 png_reset_filter_heuristics(png_ptr);
988 png_free(png_ptr, png_ptr->filter_costs);
989 png_free(png_ptr, png_ptr->inv_filter_costs);
990 #endif
991
992 #ifdef PNG_SETJMP_SUPPORTED
993 /* Reset structure */
994 png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
995 #endif
996
997 error_fn = png_ptr->error_fn;
998 #ifdef PNG_WARNINGS_SUPPORTED
999 warning_fn = png_ptr->warning_fn;
1000 #endif
1001 error_ptr = png_ptr->error_ptr;
1002 #ifdef PNG_USER_MEM_SUPPORTED
1003 free_fn = png_ptr->free_fn;
1004 #endif
1005
1006 png_memset(png_ptr, 0, png_sizeof(png_struct));
1007
1008 png_ptr->error_fn = error_fn;
1009 #ifdef PNG_WARNINGS_SUPPORTED
1010 png_ptr->warning_fn = warning_fn;
1011 #endif
1012 png_ptr->error_ptr = error_ptr;
1013 #ifdef PNG_USER_MEM_SUPPORTED
1014 png_ptr->free_fn = free_fn;
1015 #endif
1016
1017 #ifdef PNG_SETJMP_SUPPORTED
1018 png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
1019 #endif
1020 }
1021
1022 /* Allow the application to select one or more row filters to use. */
1023 void PNGAPI
png_set_filter(png_structp png_ptr,int method,int filters)1024 png_set_filter(png_structp png_ptr, int method, int filters)
1025 {
1026 png_debug(1, "in png_set_filter");
1027
1028 if (png_ptr == NULL)
1029 return;
1030
1031 #ifdef PNG_MNG_FEATURES_SUPPORTED
1032 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1033 (method == PNG_INTRAPIXEL_DIFFERENCING))
1034 method = PNG_FILTER_TYPE_BASE;
1035
1036 #endif
1037 if (method == PNG_FILTER_TYPE_BASE)
1038 {
1039 switch (filters & (PNG_ALL_FILTERS | 0x07))
1040 {
1041 #ifdef PNG_WRITE_FILTER_SUPPORTED
1042 case 5:
1043 case 6:
1044 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1045 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1046 case PNG_FILTER_VALUE_NONE:
1047 png_ptr->do_filter = PNG_FILTER_NONE; break;
1048
1049 #ifdef PNG_WRITE_FILTER_SUPPORTED
1050 case PNG_FILTER_VALUE_SUB:
1051 png_ptr->do_filter = PNG_FILTER_SUB; break;
1052
1053 case PNG_FILTER_VALUE_UP:
1054 png_ptr->do_filter = PNG_FILTER_UP; break;
1055
1056 case PNG_FILTER_VALUE_AVG:
1057 png_ptr->do_filter = PNG_FILTER_AVG; break;
1058
1059 case PNG_FILTER_VALUE_PAETH:
1060 png_ptr->do_filter = PNG_FILTER_PAETH; break;
1061
1062 default:
1063 png_ptr->do_filter = (png_byte)filters; break;
1064 #else
1065 default:
1066 png_warning(png_ptr, "Unknown row filter for method 0");
1067 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1068 }
1069
1070 /* If we have allocated the row_buf, this means we have already started
1071 * with the image and we should have allocated all of the filter buffers
1072 * that have been selected. If prev_row isn't already allocated, then
1073 * it is too late to start using the filters that need it, since we
1074 * will be missing the data in the previous row. If an application
1075 * wants to start and stop using particular filters during compression,
1076 * it should start out with all of the filters, and then add and
1077 * remove them after the start of compression.
1078 */
1079 if (png_ptr->row_buf != NULL)
1080 {
1081 #ifdef PNG_WRITE_FILTER_SUPPORTED
1082 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1083 {
1084 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1085 (png_ptr->rowbytes + 1));
1086 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1087 }
1088
1089 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1090 {
1091 if (png_ptr->prev_row == NULL)
1092 {
1093 png_warning(png_ptr, "Can't add Up filter after starting");
1094 png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1095 ~PNG_FILTER_UP);
1096 }
1097
1098 else
1099 {
1100 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1101 (png_ptr->rowbytes + 1));
1102 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1103 }
1104 }
1105
1106 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1107 {
1108 if (png_ptr->prev_row == NULL)
1109 {
1110 png_warning(png_ptr, "Can't add Average filter after starting");
1111 png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1112 ~PNG_FILTER_AVG);
1113 }
1114
1115 else
1116 {
1117 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1118 (png_ptr->rowbytes + 1));
1119 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1120 }
1121 }
1122
1123 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1124 png_ptr->paeth_row == NULL)
1125 {
1126 if (png_ptr->prev_row == NULL)
1127 {
1128 png_warning(png_ptr, "Can't add Paeth filter after starting");
1129 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1130 }
1131
1132 else
1133 {
1134 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1135 (png_ptr->rowbytes + 1));
1136 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1137 }
1138 }
1139
1140 if (png_ptr->do_filter == PNG_NO_FILTERS)
1141 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1142 png_ptr->do_filter = PNG_FILTER_NONE;
1143 }
1144 }
1145 else
1146 png_error(png_ptr, "Unknown custom filter method");
1147 }
1148
1149 /* This allows us to influence the way in which libpng chooses the "best"
1150 * filter for the current scanline. While the "minimum-sum-of-absolute-
1151 * differences metric is relatively fast and effective, there is some
1152 * question as to whether it can be improved upon by trying to keep the
1153 * filtered data going to zlib more consistent, hopefully resulting in
1154 * better compression.
1155 */
1156 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
1157 /* Convenience reset API. */
1158 static void
png_reset_filter_heuristics(png_structp png_ptr)1159 png_reset_filter_heuristics(png_structp png_ptr)
1160 {
1161 /* Clear out any old values in the 'weights' - this must be done because if
1162 * the app calls set_filter_heuristics multiple times with different
1163 * 'num_weights' values we would otherwise potentially have wrong sized
1164 * arrays.
1165 */
1166 png_ptr->num_prev_filters = 0;
1167 png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1168 if (png_ptr->prev_filters != NULL)
1169 {
1170 png_bytep old = png_ptr->prev_filters;
1171 png_ptr->prev_filters = NULL;
1172 png_free(png_ptr, old);
1173 }
1174 if (png_ptr->filter_weights != NULL)
1175 {
1176 png_uint_16p old = png_ptr->filter_weights;
1177 png_ptr->filter_weights = NULL;
1178 png_free(png_ptr, old);
1179 }
1180
1181 if (png_ptr->inv_filter_weights != NULL)
1182 {
1183 png_uint_16p old = png_ptr->inv_filter_weights;
1184 png_ptr->inv_filter_weights = NULL;
1185 png_free(png_ptr, old);
1186 }
1187
1188 /* Leave the filter_costs - this array is fixed size. */
1189 }
1190
1191 static int
png_init_filter_heuristics(png_structp png_ptr,int heuristic_method,int num_weights)1192 png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
1193 int num_weights)
1194 {
1195 if (png_ptr == NULL)
1196 return 0;
1197
1198 /* Clear out the arrays */
1199 png_reset_filter_heuristics(png_ptr);
1200
1201 /* Check arguments; the 'reset' function makes the correct settings for the
1202 * unweighted case, but we must handle the weight case by initializing the
1203 * arrays for the caller.
1204 */
1205 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1206 {
1207 int i;
1208
1209 if (num_weights > 0)
1210 {
1211 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1212 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1213
1214 /* To make sure that the weighting starts out fairly */
1215 for (i = 0; i < num_weights; i++)
1216 {
1217 png_ptr->prev_filters[i] = 255;
1218 }
1219
1220 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1221 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1222
1223 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1224 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1225
1226 for (i = 0; i < num_weights; i++)
1227 {
1228 png_ptr->inv_filter_weights[i] =
1229 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1230 }
1231
1232 /* Safe to set this now */
1233 png_ptr->num_prev_filters = (png_byte)num_weights;
1234 }
1235
1236 /* If, in the future, there are other filter methods, this would
1237 * need to be based on png_ptr->filter.
1238 */
1239 if (png_ptr->filter_costs == NULL)
1240 {
1241 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1242 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1243
1244 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1245 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1246 }
1247
1248 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1249 {
1250 png_ptr->inv_filter_costs[i] =
1251 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1252 }
1253
1254 /* All the arrays are inited, safe to set this: */
1255 png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
1256
1257 /* Return the 'ok' code. */
1258 return 1;
1259 }
1260 else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
1261 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1262 {
1263 return 1;
1264 }
1265 else
1266 {
1267 png_warning(png_ptr, "Unknown filter heuristic method");
1268 return 0;
1269 }
1270 }
1271
1272 /* Provide floating and fixed point APIs */
1273 #ifdef PNG_FLOATING_POINT_SUPPORTED
1274 void PNGAPI
png_set_filter_heuristics(png_structp png_ptr,int heuristic_method,int num_weights,png_const_doublep filter_weights,png_const_doublep filter_costs)1275 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1276 int num_weights, png_const_doublep filter_weights,
1277 png_const_doublep filter_costs)
1278 {
1279 png_debug(1, "in png_set_filter_heuristics");
1280
1281 /* The internal API allocates all the arrays and ensures that the elements of
1282 * those arrays are set to the default value.
1283 */
1284 if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1285 return;
1286
1287 /* If using the weighted method copy in the weights. */
1288 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1289 {
1290 int i;
1291 for (i = 0; i < num_weights; i++)
1292 {
1293 if (filter_weights[i] <= 0.0)
1294 {
1295 png_ptr->inv_filter_weights[i] =
1296 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1297 }
1298
1299 else
1300 {
1301 png_ptr->inv_filter_weights[i] =
1302 (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
1303
1304 png_ptr->filter_weights[i] =
1305 (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
1306 }
1307 }
1308
1309 /* Here is where we set the relative costs of the different filters. We
1310 * should take the desired compression level into account when setting
1311 * the costs, so that Paeth, for instance, has a high relative cost at low
1312 * compression levels, while it has a lower relative cost at higher
1313 * compression settings. The filter types are in order of increasing
1314 * relative cost, so it would be possible to do this with an algorithm.
1315 */
1316 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
1317 {
1318 png_ptr->inv_filter_costs[i] =
1319 (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
1320
1321 png_ptr->filter_costs[i] =
1322 (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
1323 }
1324 }
1325 }
1326 #endif /* FLOATING_POINT */
1327
1328 #ifdef PNG_FIXED_POINT_SUPPORTED
1329 void PNGAPI
png_set_filter_heuristics_fixed(png_structp png_ptr,int heuristic_method,int num_weights,png_const_fixed_point_p filter_weights,png_const_fixed_point_p filter_costs)1330 png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
1331 int num_weights, png_const_fixed_point_p filter_weights,
1332 png_const_fixed_point_p filter_costs)
1333 {
1334 png_debug(1, "in png_set_filter_heuristics_fixed");
1335
1336 /* The internal API allocates all the arrays and ensures that the elements of
1337 * those arrays are set to the default value.
1338 */
1339 if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1340 return;
1341
1342 /* If using the weighted method copy in the weights. */
1343 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1344 {
1345 int i;
1346 for (i = 0; i < num_weights; i++)
1347 {
1348 if (filter_weights[i] <= 0)
1349 {
1350 png_ptr->inv_filter_weights[i] =
1351 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1352 }
1353
1354 else
1355 {
1356 png_ptr->inv_filter_weights[i] = (png_uint_16)
1357 ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
1358
1359 png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
1360 PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
1361 }
1362 }
1363
1364 /* Here is where we set the relative costs of the different filters. We
1365 * should take the desired compression level into account when setting
1366 * the costs, so that Paeth, for instance, has a high relative cost at low
1367 * compression levels, while it has a lower relative cost at higher
1368 * compression settings. The filter types are in order of increasing
1369 * relative cost, so it would be possible to do this with an algorithm.
1370 */
1371 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1372 if (filter_costs[i] >= PNG_FP_1)
1373 {
1374 png_uint_32 tmp;
1375
1376 /* Use a 32 bit unsigned temporary here because otherwise the
1377 * intermediate value will be a 32 bit *signed* integer (ANSI rules)
1378 * and this will get the wrong answer on division.
1379 */
1380 tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
1381 tmp /= filter_costs[i];
1382
1383 png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
1384
1385 tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
1386 tmp /= PNG_FP_1;
1387
1388 png_ptr->filter_costs[i] = (png_uint_16)tmp;
1389 }
1390 }
1391 }
1392 #endif /* FIXED_POINT */
1393 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1394
1395 void PNGAPI
png_set_compression_level(png_structp png_ptr,int level)1396 png_set_compression_level(png_structp png_ptr, int level)
1397 {
1398 png_debug(1, "in png_set_compression_level");
1399
1400 if (png_ptr == NULL)
1401 return;
1402
1403 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1404 png_ptr->zlib_level = level;
1405 }
1406
1407 void PNGAPI
png_set_compression_mem_level(png_structp png_ptr,int mem_level)1408 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1409 {
1410 png_debug(1, "in png_set_compression_mem_level");
1411
1412 if (png_ptr == NULL)
1413 return;
1414
1415 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1416 png_ptr->zlib_mem_level = mem_level;
1417 }
1418
1419 void PNGAPI
png_set_compression_strategy(png_structp png_ptr,int strategy)1420 png_set_compression_strategy(png_structp png_ptr, int strategy)
1421 {
1422 png_debug(1, "in png_set_compression_strategy");
1423
1424 if (png_ptr == NULL)
1425 return;
1426
1427 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1428 png_ptr->zlib_strategy = strategy;
1429 }
1430
1431 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1432 * smaller value of window_bits if it can do so safely.
1433 */
1434 void PNGAPI
png_set_compression_window_bits(png_structp png_ptr,int window_bits)1435 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1436 {
1437 if (png_ptr == NULL)
1438 return;
1439
1440 if (window_bits > 15)
1441 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1442
1443 else if (window_bits < 8)
1444 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1445
1446 #ifndef WBITS_8_OK
1447 /* Avoid libpng bug with 256-byte windows */
1448 if (window_bits == 8)
1449 {
1450 png_warning(png_ptr, "Compression window is being reset to 512");
1451 window_bits = 9;
1452 }
1453
1454 #endif
1455 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1456 png_ptr->zlib_window_bits = window_bits;
1457 }
1458
1459 void PNGAPI
png_set_compression_method(png_structp png_ptr,int method)1460 png_set_compression_method(png_structp png_ptr, int method)
1461 {
1462 png_debug(1, "in png_set_compression_method");
1463
1464 if (png_ptr == NULL)
1465 return;
1466
1467 if (method != 8)
1468 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1469
1470 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1471 png_ptr->zlib_method = method;
1472 }
1473
1474 /* The following were added to libpng-1.5.4 */
1475 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1476 void PNGAPI
png_set_text_compression_level(png_structp png_ptr,int level)1477 png_set_text_compression_level(png_structp png_ptr, int level)
1478 {
1479 png_debug(1, "in png_set_text_compression_level");
1480
1481 if (png_ptr == NULL)
1482 return;
1483
1484 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
1485 png_ptr->zlib_text_level = level;
1486 }
1487
1488 void PNGAPI
png_set_text_compression_mem_level(png_structp png_ptr,int mem_level)1489 png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
1490 {
1491 png_debug(1, "in png_set_text_compression_mem_level");
1492
1493 if (png_ptr == NULL)
1494 return;
1495
1496 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
1497 png_ptr->zlib_text_mem_level = mem_level;
1498 }
1499
1500 void PNGAPI
png_set_text_compression_strategy(png_structp png_ptr,int strategy)1501 png_set_text_compression_strategy(png_structp png_ptr, int strategy)
1502 {
1503 png_debug(1, "in png_set_text_compression_strategy");
1504
1505 if (png_ptr == NULL)
1506 return;
1507
1508 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
1509 png_ptr->zlib_text_strategy = strategy;
1510 }
1511
1512 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1513 * smaller value of window_bits if it can do so safely.
1514 */
1515 void PNGAPI
png_set_text_compression_window_bits(png_structp png_ptr,int window_bits)1516 png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
1517 {
1518 if (png_ptr == NULL)
1519 return;
1520
1521 if (window_bits > 15)
1522 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1523
1524 else if (window_bits < 8)
1525 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1526
1527 #ifndef WBITS_8_OK
1528 /* Avoid libpng bug with 256-byte windows */
1529 if (window_bits == 8)
1530 {
1531 png_warning(png_ptr, "Text compression window is being reset to 512");
1532 window_bits = 9;
1533 }
1534
1535 #endif
1536 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
1537 png_ptr->zlib_text_window_bits = window_bits;
1538 }
1539
1540 void PNGAPI
png_set_text_compression_method(png_structp png_ptr,int method)1541 png_set_text_compression_method(png_structp png_ptr, int method)
1542 {
1543 png_debug(1, "in png_set_text_compression_method");
1544
1545 if (png_ptr == NULL)
1546 return;
1547
1548 if (method != 8)
1549 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1550
1551 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
1552 png_ptr->zlib_text_method = method;
1553 }
1554 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1555 /* end of API added to libpng-1.5.4 */
1556
1557 void PNGAPI
png_set_write_status_fn(png_structp png_ptr,png_write_status_ptr write_row_fn)1558 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1559 {
1560 if (png_ptr == NULL)
1561 return;
1562
1563 png_ptr->write_row_fn = write_row_fn;
1564 }
1565
1566 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1567 void PNGAPI
png_set_write_user_transform_fn(png_structp png_ptr,png_user_transform_ptr write_user_transform_fn)1568 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1569 write_user_transform_fn)
1570 {
1571 png_debug(1, "in png_set_write_user_transform_fn");
1572
1573 if (png_ptr == NULL)
1574 return;
1575
1576 png_ptr->transformations |= PNG_USER_TRANSFORM;
1577 png_ptr->write_user_transform_fn = write_user_transform_fn;
1578 }
1579 #endif
1580
1581
1582 #ifdef PNG_INFO_IMAGE_SUPPORTED
1583 void PNGAPI
png_write_png(png_structp png_ptr,png_infop info_ptr,int transforms,voidp params)1584 png_write_png(png_structp png_ptr, png_infop info_ptr,
1585 int transforms, voidp params)
1586 {
1587 if (png_ptr == NULL || info_ptr == NULL)
1588 return;
1589
1590 /* Write the file header information. */
1591 png_write_info(png_ptr, info_ptr);
1592
1593 /* ------ these transformations don't touch the info structure ------- */
1594
1595 #ifdef PNG_WRITE_INVERT_SUPPORTED
1596 /* Invert monochrome pixels */
1597 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1598 png_set_invert_mono(png_ptr);
1599 #endif
1600
1601 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1602 /* Shift the pixels up to a legal bit depth and fill in
1603 * as appropriate to correctly scale the image.
1604 */
1605 if ((transforms & PNG_TRANSFORM_SHIFT)
1606 && (info_ptr->valid & PNG_INFO_sBIT))
1607 png_set_shift(png_ptr, &info_ptr->sig_bit);
1608 #endif
1609
1610 #ifdef PNG_WRITE_PACK_SUPPORTED
1611 /* Pack pixels into bytes */
1612 if (transforms & PNG_TRANSFORM_PACKING)
1613 png_set_packing(png_ptr);
1614 #endif
1615
1616 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1617 /* Swap location of alpha bytes from ARGB to RGBA */
1618 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1619 png_set_swap_alpha(png_ptr);
1620 #endif
1621
1622 #ifdef PNG_WRITE_FILLER_SUPPORTED
1623 /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
1624 if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1625 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1626
1627 else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1628 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1629 #endif
1630
1631 #ifdef PNG_WRITE_BGR_SUPPORTED
1632 /* Flip BGR pixels to RGB */
1633 if (transforms & PNG_TRANSFORM_BGR)
1634 png_set_bgr(png_ptr);
1635 #endif
1636
1637 #ifdef PNG_WRITE_SWAP_SUPPORTED
1638 /* Swap bytes of 16-bit files to most significant byte first */
1639 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1640 png_set_swap(png_ptr);
1641 #endif
1642
1643 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1644 /* Swap bits of 1, 2, 4 bit packed pixel formats */
1645 if (transforms & PNG_TRANSFORM_PACKSWAP)
1646 png_set_packswap(png_ptr);
1647 #endif
1648
1649 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1650 /* Invert the alpha channel from opacity to transparency */
1651 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1652 png_set_invert_alpha(png_ptr);
1653 #endif
1654
1655 /* ----------------------- end of transformations ------------------- */
1656
1657 /* Write the bits */
1658 if (info_ptr->valid & PNG_INFO_IDAT)
1659 png_write_image(png_ptr, info_ptr->row_pointers);
1660
1661 /* It is REQUIRED to call this to finish writing the rest of the file */
1662 png_write_end(png_ptr, info_ptr);
1663
1664 PNG_UNUSED(transforms) /* Quiet compiler warnings */
1665 PNG_UNUSED(params)
1666 }
1667 #endif
1668 #endif /* PNG_WRITE_SUPPORTED */
1669