1
2 /* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.2.15 January 5, 2007
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2007 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 */
10
11 /* get internal access to png.h */
12 #define PNG_INTERNAL
13 #include "png.h"
14 #ifdef PNG_WRITE_SUPPORTED
15
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
png_write_info_before_PLTE(png_structp png_ptr,png_infop info_ptr)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;
101
102 png_debug(5, "writing extra chunks\n");
103
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 png_write_chunk(png_ptr, up->name, up->data, up->size);
116 }
117 }
118 }
119 #endif
120 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
121 }
122 }
123
124 void PNGAPI
png_write_info(png_structp png_ptr,png_infop info_ptr)125 png_write_info(png_structp png_ptr, png_infop info_ptr)
126 {
127 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
128 int i;
129 #endif
130
131 png_debug(1, "in png_write_info\n");
132
133 if (png_ptr == NULL || info_ptr == NULL)
134 return;
135
136 png_write_info_before_PLTE(png_ptr, info_ptr);
137
138 if (info_ptr->valid & PNG_INFO_PLTE)
139 png_write_PLTE(png_ptr, info_ptr->palette,
140 (png_uint_32)info_ptr->num_palette);
141 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
142 png_error(png_ptr, "Valid palette required for paletted images");
143
144 #if defined(PNG_WRITE_tRNS_SUPPORTED)
145 if (info_ptr->valid & PNG_INFO_tRNS)
146 {
147 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
148 /* invert the alpha channel (in tRNS) */
149 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
150 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
151 {
152 int j;
153 for (j=0; j<(int)info_ptr->num_trans; j++)
154 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
155 }
156 #endif
157 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
158 info_ptr->num_trans, info_ptr->color_type);
159 }
160 #endif
161 #if defined(PNG_WRITE_bKGD_SUPPORTED)
162 if (info_ptr->valid & PNG_INFO_bKGD)
163 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
164 #endif
165 #if defined(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 #if defined(PNG_WRITE_oFFs_SUPPORTED)
170 if (info_ptr->valid & PNG_INFO_oFFs)
171 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
172 info_ptr->offset_unit_type);
173 #endif
174 #if defined(PNG_WRITE_pCAL_SUPPORTED)
175 if (info_ptr->valid & PNG_INFO_pCAL)
176 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
177 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
178 info_ptr->pcal_units, info_ptr->pcal_params);
179 #endif
180 #if defined(PNG_WRITE_sCAL_SUPPORTED)
181 if (info_ptr->valid & PNG_INFO_sCAL)
182 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
183 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
184 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
185 #else
186 #ifdef PNG_FIXED_POINT_SUPPORTED
187 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
188 info_ptr->scal_s_width, info_ptr->scal_s_height);
189 #else
190 png_warning(png_ptr,
191 "png_write_sCAL not supported; sCAL chunk not written.");
192 #endif
193 #endif
194 #endif
195 #if defined(PNG_WRITE_pHYs_SUPPORTED)
196 if (info_ptr->valid & PNG_INFO_pHYs)
197 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
198 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
199 #endif
200 #if defined(PNG_WRITE_tIME_SUPPORTED)
201 if (info_ptr->valid & PNG_INFO_tIME)
202 {
203 png_write_tIME(png_ptr, &(info_ptr->mod_time));
204 png_ptr->mode |= PNG_WROTE_tIME;
205 }
206 #endif
207 #if defined(PNG_WRITE_sPLT_SUPPORTED)
208 if (info_ptr->valid & PNG_INFO_sPLT)
209 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
210 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
211 #endif
212 #if defined(PNG_WRITE_TEXT_SUPPORTED)
213 /* Check to see if we need to write text chunks */
214 for (i = 0; i < info_ptr->num_text; i++)
215 {
216 png_debug2(2, "Writing header text chunk %d, type %d\n", i,
217 info_ptr->text[i].compression);
218 /* an internationalized chunk? */
219 if (info_ptr->text[i].compression > 0)
220 {
221 #if defined(PNG_WRITE_iTXt_SUPPORTED)
222 /* write international chunk */
223 png_write_iTXt(png_ptr,
224 info_ptr->text[i].compression,
225 info_ptr->text[i].key,
226 info_ptr->text[i].lang,
227 info_ptr->text[i].lang_key,
228 info_ptr->text[i].text);
229 #else
230 png_warning(png_ptr, "Unable to write international text");
231 #endif
232 /* Mark this chunk as written */
233 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
234 }
235 /* If we want a compressed text chunk */
236 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
237 {
238 #if defined(PNG_WRITE_zTXt_SUPPORTED)
239 /* write compressed chunk */
240 png_write_zTXt(png_ptr, info_ptr->text[i].key,
241 info_ptr->text[i].text, 0,
242 info_ptr->text[i].compression);
243 #else
244 png_warning(png_ptr, "Unable to write compressed text");
245 #endif
246 /* Mark this chunk as written */
247 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
248 }
249 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
250 {
251 #if defined(PNG_WRITE_tEXt_SUPPORTED)
252 /* write uncompressed chunk */
253 png_write_tEXt(png_ptr, info_ptr->text[i].key,
254 info_ptr->text[i].text,
255 0);
256 #else
257 png_warning(png_ptr, "Unable to write uncompressed text");
258 #endif
259 /* Mark this chunk as written */
260 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
261 }
262 }
263 #endif
264 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
265 if (info_ptr->unknown_chunks_num)
266 {
267 png_unknown_chunk *up;
268
269 png_debug(5, "writing extra chunks\n");
270
271 for (up = info_ptr->unknown_chunks;
272 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
273 up++)
274 {
275 int keep=png_handle_as_unknown(png_ptr, up->name);
276 if (keep != PNG_HANDLE_CHUNK_NEVER &&
277 up->location && (up->location & PNG_HAVE_PLTE) &&
278 !(up->location & PNG_HAVE_IDAT) &&
279 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
280 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
281 {
282 png_write_chunk(png_ptr, up->name, up->data, up->size);
283 }
284 }
285 }
286 #endif
287 }
288
289 /* Writes the end of the PNG file. If you don't want to write comments or
290 * time information, you can pass NULL for info. If you already wrote these
291 * in png_write_info(), do not write them again here. If you have long
292 * comments, I suggest writing them here, and compressing them.
293 */
294 void PNGAPI
png_write_end(png_structp png_ptr,png_infop info_ptr)295 png_write_end(png_structp png_ptr, png_infop info_ptr)
296 {
297 png_debug(1, "in png_write_end\n");
298 if (png_ptr == NULL)
299 return;
300 if (!(png_ptr->mode & PNG_HAVE_IDAT))
301 png_error(png_ptr, "No IDATs written into file");
302
303 /* see if user wants us to write information chunks */
304 if (info_ptr != NULL)
305 {
306 #if defined(PNG_WRITE_TEXT_SUPPORTED)
307 int i; /* local index variable */
308 #endif
309 #if defined(PNG_WRITE_tIME_SUPPORTED)
310 /* check to see if user has supplied a time chunk */
311 if ((info_ptr->valid & PNG_INFO_tIME) &&
312 !(png_ptr->mode & PNG_WROTE_tIME))
313 png_write_tIME(png_ptr, &(info_ptr->mod_time));
314 #endif
315 #if defined(PNG_WRITE_TEXT_SUPPORTED)
316 /* loop through comment chunks */
317 for (i = 0; i < info_ptr->num_text; i++)
318 {
319 png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
320 info_ptr->text[i].compression);
321 /* an internationalized chunk? */
322 if (info_ptr->text[i].compression > 0)
323 {
324 #if defined(PNG_WRITE_iTXt_SUPPORTED)
325 /* write international chunk */
326 png_write_iTXt(png_ptr,
327 info_ptr->text[i].compression,
328 info_ptr->text[i].key,
329 info_ptr->text[i].lang,
330 info_ptr->text[i].lang_key,
331 info_ptr->text[i].text);
332 #else
333 png_warning(png_ptr, "Unable to write international text");
334 #endif
335 /* Mark this chunk as written */
336 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
337 }
338 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
339 {
340 #if defined(PNG_WRITE_zTXt_SUPPORTED)
341 /* write compressed chunk */
342 png_write_zTXt(png_ptr, info_ptr->text[i].key,
343 info_ptr->text[i].text, 0,
344 info_ptr->text[i].compression);
345 #else
346 png_warning(png_ptr, "Unable to write compressed text");
347 #endif
348 /* Mark this chunk as written */
349 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
350 }
351 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
352 {
353 #if defined(PNG_WRITE_tEXt_SUPPORTED)
354 /* write uncompressed chunk */
355 png_write_tEXt(png_ptr, info_ptr->text[i].key,
356 info_ptr->text[i].text, 0);
357 #else
358 png_warning(png_ptr, "Unable to write uncompressed text");
359 #endif
360
361 /* Mark this chunk as written */
362 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
363 }
364 }
365 #endif
366 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
367 if (info_ptr->unknown_chunks_num)
368 {
369 png_unknown_chunk *up;
370
371 png_debug(5, "writing extra chunks\n");
372
373 for (up = info_ptr->unknown_chunks;
374 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
375 up++)
376 {
377 int keep=png_handle_as_unknown(png_ptr, up->name);
378 if (keep != PNG_HANDLE_CHUNK_NEVER &&
379 up->location && (up->location & PNG_AFTER_IDAT) &&
380 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
381 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
382 {
383 png_write_chunk(png_ptr, up->name, up->data, up->size);
384 }
385 }
386 }
387 #endif
388 }
389
390 png_ptr->mode |= PNG_AFTER_IDAT;
391
392 /* write end of PNG file */
393 png_write_IEND(png_ptr);
394 }
395
396 #if defined(PNG_WRITE_tIME_SUPPORTED)
397 #if !defined(_WIN32_WCE)
398 /* "time.h" functions are not supported on WindowsCE */
399 void PNGAPI
png_convert_from_struct_tm(png_timep ptime,struct tm FAR * ttime)400 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
401 {
402 png_debug(1, "in png_convert_from_struct_tm\n");
403 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
404 ptime->month = (png_byte)(ttime->tm_mon + 1);
405 ptime->day = (png_byte)ttime->tm_mday;
406 ptime->hour = (png_byte)ttime->tm_hour;
407 ptime->minute = (png_byte)ttime->tm_min;
408 ptime->second = (png_byte)ttime->tm_sec;
409 }
410
411 void PNGAPI
png_convert_from_time_t(png_timep ptime,time_t ttime)412 png_convert_from_time_t(png_timep ptime, time_t ttime)
413 {
414 struct tm *tbuf;
415
416 png_debug(1, "in png_convert_from_time_t\n");
417 tbuf = gmtime(&ttime);
418 png_convert_from_struct_tm(ptime, tbuf);
419 }
420 #endif
421 #endif
422
423 /* Initialize png_ptr structure, and allocate any memory needed */
424 png_structp PNGAPI
png_create_write_struct(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn)425 png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
426 png_error_ptr error_fn, png_error_ptr warn_fn)
427 {
428 #ifdef PNG_USER_MEM_SUPPORTED
429 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
430 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
431 }
432
433 /* Alternate initialize png_ptr structure, and allocate any memory needed */
434 png_structp PNGAPI
png_create_write_struct_2(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn,png_voidp mem_ptr,png_malloc_ptr malloc_fn,png_free_ptr free_fn)435 png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
436 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
437 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
438 {
439 #endif /* PNG_USER_MEM_SUPPORTED */
440 png_structp png_ptr;
441 #ifdef PNG_SETJMP_SUPPORTED
442 #ifdef USE_FAR_KEYWORD
443 jmp_buf jmpbuf;
444 #endif
445 #endif
446 int i;
447 png_debug(1, "in png_create_write_struct\n");
448 #ifdef PNG_USER_MEM_SUPPORTED
449 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
450 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
451 #else
452 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
453 #endif /* PNG_USER_MEM_SUPPORTED */
454 if (png_ptr == NULL)
455 return (NULL);
456
457 #if !defined(PNG_1_0_X)
458 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
459 #ifdef PNG_MMX_CODE_SUPPORTED
460 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
461 #endif
462 #endif
463 #endif /* PNG_1_0_X */
464
465 /* added at libpng-1.2.6 */
466 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
467 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
468 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
469 #endif
470
471 #ifdef PNG_SETJMP_SUPPORTED
472 #ifdef USE_FAR_KEYWORD
473 if (setjmp(jmpbuf))
474 #else
475 if (setjmp(png_ptr->jmpbuf))
476 #endif
477 {
478 png_free(png_ptr, png_ptr->zbuf);
479 png_ptr->zbuf=NULL;
480 png_destroy_struct(png_ptr);
481 return (NULL);
482 }
483 #ifdef USE_FAR_KEYWORD
484 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
485 #endif
486 #endif
487
488 #ifdef PNG_USER_MEM_SUPPORTED
489 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
490 #endif /* PNG_USER_MEM_SUPPORTED */
491 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
492
493 i=0;
494 do
495 {
496 if(user_png_ver[i] != png_libpng_ver[i])
497 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
498 } while (png_libpng_ver[i++]);
499
500 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
501 {
502 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
503 * we must recompile any applications that use any older library version.
504 * For versions after libpng 1.0, we will be compatible, so we need
505 * only check the first digit.
506 */
507 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
508 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
509 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
510 {
511 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
512 char msg[80];
513 if (user_png_ver)
514 {
515 png_snprintf(msg, 80,
516 "Application was compiled with png.h from libpng-%.20s",
517 user_png_ver);
518 png_warning(png_ptr, msg);
519 }
520 png_snprintf(msg, 80,
521 "Application is running with png.c from libpng-%.20s",
522 png_libpng_ver);
523 png_warning(png_ptr, msg);
524 #endif
525 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
526 png_ptr->flags=0;
527 #endif
528 png_error(png_ptr,
529 "Incompatible libpng version in application and library");
530 }
531 }
532
533 /* initialize zbuf - compression buffer */
534 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
535 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
536 (png_uint_32)png_ptr->zbuf_size);
537
538 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
539 png_flush_ptr_NULL);
540
541 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
542 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
543 1, png_doublep_NULL, png_doublep_NULL);
544 #endif
545
546 #ifdef PNG_SETJMP_SUPPORTED
547 /* Applications that neglect to set up their own setjmp() and then encounter
548 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
549 abort instead of returning. */
550 #ifdef USE_FAR_KEYWORD
551 if (setjmp(jmpbuf))
552 PNG_ABORT();
553 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
554 #else
555 if (setjmp(png_ptr->jmpbuf))
556 PNG_ABORT();
557 #endif
558 #endif
559 return (png_ptr);
560 }
561
562 /* Initialize png_ptr structure, and allocate any memory needed */
563 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
564 /* Deprecated. */
565 #undef png_write_init
566 void PNGAPI
png_write_init(png_structp png_ptr)567 png_write_init(png_structp png_ptr)
568 {
569 /* We only come here via pre-1.0.7-compiled applications */
570 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
571 }
572
573 void PNGAPI
png_write_init_2(png_structp png_ptr,png_const_charp user_png_ver,png_size_t png_struct_size,png_size_t png_info_size)574 png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
575 png_size_t png_struct_size, png_size_t png_info_size)
576 {
577 /* We only come here via pre-1.0.12-compiled applications */
578 if(png_ptr == NULL) return;
579 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
580 if(png_sizeof(png_struct) > png_struct_size ||
581 png_sizeof(png_info) > png_info_size)
582 {
583 char msg[80];
584 png_ptr->warning_fn=NULL;
585 if (user_png_ver)
586 {
587 png_snprintf(msg, 80,
588 "Application was compiled with png.h from libpng-%.20s",
589 user_png_ver);
590 png_warning(png_ptr, msg);
591 }
592 png_snprintf(msg, 80,
593 "Application is running with png.c from libpng-%.20s",
594 png_libpng_ver);
595 png_warning(png_ptr, msg);
596 }
597 #endif
598 if(png_sizeof(png_struct) > png_struct_size)
599 {
600 png_ptr->error_fn=NULL;
601 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
602 png_ptr->flags=0;
603 #endif
604 png_error(png_ptr,
605 "The png struct allocated by the application for writing is too small.");
606 }
607 if(png_sizeof(png_info) > png_info_size)
608 {
609 png_ptr->error_fn=NULL;
610 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
611 png_ptr->flags=0;
612 #endif
613 png_error(png_ptr,
614 "The info struct allocated by the application for writing is too small.");
615 }
616 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
617 }
618 #endif /* PNG_1_0_X || PNG_1_2_X */
619
620
621 void PNGAPI
png_write_init_3(png_structpp ptr_ptr,png_const_charp user_png_ver,png_size_t png_struct_size)622 png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
623 png_size_t png_struct_size)
624 {
625 png_structp png_ptr=*ptr_ptr;
626 #ifdef PNG_SETJMP_SUPPORTED
627 jmp_buf tmp_jmp; /* to save current jump buffer */
628 #endif
629
630 int i = 0;
631
632 if (png_ptr == NULL)
633 return;
634
635 do
636 {
637 if (user_png_ver[i] != png_libpng_ver[i])
638 {
639 #ifdef PNG_LEGACY_SUPPORTED
640 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
641 #else
642 png_ptr->warning_fn=NULL;
643 png_warning(png_ptr,
644 "Application uses deprecated png_write_init() and should be recompiled.");
645 break;
646 #endif
647 }
648 } while (png_libpng_ver[i++]);
649
650 png_debug(1, "in png_write_init_3\n");
651
652 #ifdef PNG_SETJMP_SUPPORTED
653 /* save jump buffer and error functions */
654 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
655 #endif
656
657 if (png_sizeof(png_struct) > png_struct_size)
658 {
659 png_destroy_struct(png_ptr);
660 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
661 *ptr_ptr = png_ptr;
662 }
663
664 /* reset all variables to 0 */
665 png_memset(png_ptr, 0, png_sizeof (png_struct));
666
667 /* added at libpng-1.2.6 */
668 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
669 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
670 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
671 #endif
672
673 #if !defined(PNG_1_0_X)
674 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
675 #ifdef PNG_MMX_CODE_SUPPORTED
676 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
677 #endif
678 #endif
679 #endif /* PNG_1_0_X */
680
681 #ifdef PNG_SETJMP_SUPPORTED
682 /* restore jump buffer */
683 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
684 #endif
685
686 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
687 png_flush_ptr_NULL);
688
689 /* initialize zbuf - compression buffer */
690 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
691 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
692 (png_uint_32)png_ptr->zbuf_size);
693
694 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
695 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
696 1, png_doublep_NULL, png_doublep_NULL);
697 #endif
698 }
699
700 /* Write a few rows of image data. If the image is interlaced,
701 * either you will have to write the 7 sub images, or, if you
702 * have called png_set_interlace_handling(), you will have to
703 * "write" the image seven times.
704 */
705 void PNGAPI
png_write_rows(png_structp png_ptr,png_bytepp row,png_uint_32 num_rows)706 png_write_rows(png_structp png_ptr, png_bytepp row,
707 png_uint_32 num_rows)
708 {
709 png_uint_32 i; /* row counter */
710 png_bytepp rp; /* row pointer */
711
712 png_debug(1, "in png_write_rows\n");
713
714 if (png_ptr == NULL)
715 return;
716
717 /* loop through the rows */
718 for (i = 0, rp = row; i < num_rows; i++, rp++)
719 {
720 png_write_row(png_ptr, *rp);
721 }
722 }
723
724 /* Write the image. You only need to call this function once, even
725 * if you are writing an interlaced image.
726 */
727 void PNGAPI
png_write_image(png_structp png_ptr,png_bytepp image)728 png_write_image(png_structp png_ptr, png_bytepp image)
729 {
730 png_uint_32 i; /* row index */
731 int pass, num_pass; /* pass variables */
732 png_bytepp rp; /* points to current row */
733
734 if (png_ptr == NULL)
735 return;
736
737 png_debug(1, "in png_write_image\n");
738 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
739 /* intialize interlace handling. If image is not interlaced,
740 this will set pass to 1 */
741 num_pass = png_set_interlace_handling(png_ptr);
742 #else
743 num_pass = 1;
744 #endif
745 /* loop through passes */
746 for (pass = 0; pass < num_pass; pass++)
747 {
748 /* loop through image */
749 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
750 {
751 png_write_row(png_ptr, *rp);
752 }
753 }
754 }
755
756 /* called by user to write a row of image data */
757 void PNGAPI
png_write_row(png_structp png_ptr,png_bytep row)758 png_write_row(png_structp png_ptr, png_bytep row)
759 {
760 if (png_ptr == NULL)
761 return;
762 png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
763 png_ptr->row_number, png_ptr->pass);
764
765 /* initialize transformations and other stuff if first time */
766 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
767 {
768 /* make sure we wrote the header info */
769 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
770 png_error(png_ptr,
771 "png_write_info was never called before png_write_row.");
772
773 /* check for transforms that have been set but were defined out */
774 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
775 if (png_ptr->transformations & PNG_INVERT_MONO)
776 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
777 #endif
778 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
779 if (png_ptr->transformations & PNG_FILLER)
780 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
781 #endif
782 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
783 if (png_ptr->transformations & PNG_PACKSWAP)
784 png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
785 #endif
786 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
787 if (png_ptr->transformations & PNG_PACK)
788 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
789 #endif
790 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
791 if (png_ptr->transformations & PNG_SHIFT)
792 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
793 #endif
794 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
795 if (png_ptr->transformations & PNG_BGR)
796 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
797 #endif
798 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
799 if (png_ptr->transformations & PNG_SWAP_BYTES)
800 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
801 #endif
802
803 png_write_start_row(png_ptr);
804 }
805
806 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
807 /* if interlaced and not interested in row, return */
808 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
809 {
810 switch (png_ptr->pass)
811 {
812 case 0:
813 if (png_ptr->row_number & 0x07)
814 {
815 png_write_finish_row(png_ptr);
816 return;
817 }
818 break;
819 case 1:
820 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
821 {
822 png_write_finish_row(png_ptr);
823 return;
824 }
825 break;
826 case 2:
827 if ((png_ptr->row_number & 0x07) != 4)
828 {
829 png_write_finish_row(png_ptr);
830 return;
831 }
832 break;
833 case 3:
834 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
835 {
836 png_write_finish_row(png_ptr);
837 return;
838 }
839 break;
840 case 4:
841 if ((png_ptr->row_number & 0x03) != 2)
842 {
843 png_write_finish_row(png_ptr);
844 return;
845 }
846 break;
847 case 5:
848 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
849 {
850 png_write_finish_row(png_ptr);
851 return;
852 }
853 break;
854 case 6:
855 if (!(png_ptr->row_number & 0x01))
856 {
857 png_write_finish_row(png_ptr);
858 return;
859 }
860 break;
861 }
862 }
863 #endif
864
865 /* set up row info for transformations */
866 png_ptr->row_info.color_type = png_ptr->color_type;
867 png_ptr->row_info.width = png_ptr->usr_width;
868 png_ptr->row_info.channels = png_ptr->usr_channels;
869 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
870 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
871 png_ptr->row_info.channels);
872
873 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
874 png_ptr->row_info.width);
875
876 png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
877 png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
878 png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
879 png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
880 png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
881 png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
882
883 /* Copy user's row into buffer, leaving room for filter byte. */
884 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
885 png_ptr->row_info.rowbytes);
886
887 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
888 /* handle interlacing */
889 if (png_ptr->interlaced && png_ptr->pass < 6 &&
890 (png_ptr->transformations & PNG_INTERLACE))
891 {
892 png_do_write_interlace(&(png_ptr->row_info),
893 png_ptr->row_buf + 1, png_ptr->pass);
894 /* this should always get caught above, but still ... */
895 if (!(png_ptr->row_info.width))
896 {
897 png_write_finish_row(png_ptr);
898 return;
899 }
900 }
901 #endif
902
903 /* handle other transformations */
904 if (png_ptr->transformations)
905 png_do_write_transformations(png_ptr);
906
907 #if defined(PNG_MNG_FEATURES_SUPPORTED)
908 /* Write filter_method 64 (intrapixel differencing) only if
909 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
910 * 2. Libpng did not write a PNG signature (this filter_method is only
911 * used in PNG datastreams that are embedded in MNG datastreams) and
912 * 3. The application called png_permit_mng_features with a mask that
913 * included PNG_FLAG_MNG_FILTER_64 and
914 * 4. The filter_method is 64 and
915 * 5. The color_type is RGB or RGBA
916 */
917 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
918 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
919 {
920 /* Intrapixel differencing */
921 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
922 }
923 #endif
924
925 /* Find a filter if necessary, filter the row and write it out. */
926 png_write_find_filter(png_ptr, &(png_ptr->row_info));
927
928 if (png_ptr->write_row_fn != NULL)
929 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
930 }
931
932 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
933 /* Set the automatic flush interval or 0 to turn flushing off */
934 void PNGAPI
png_set_flush(png_structp png_ptr,int nrows)935 png_set_flush(png_structp png_ptr, int nrows)
936 {
937 png_debug(1, "in png_set_flush\n");
938 if (png_ptr == NULL)
939 return;
940 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
941 }
942
943 /* flush the current output buffers now */
944 void PNGAPI
png_write_flush(png_structp png_ptr)945 png_write_flush(png_structp png_ptr)
946 {
947 int wrote_IDAT;
948
949 png_debug(1, "in png_write_flush\n");
950 if (png_ptr == NULL)
951 return;
952 /* We have already written out all of the data */
953 if (png_ptr->row_number >= png_ptr->num_rows)
954 return;
955
956 do
957 {
958 int ret;
959
960 /* compress the data */
961 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
962 wrote_IDAT = 0;
963
964 /* check for compression errors */
965 if (ret != Z_OK)
966 {
967 if (png_ptr->zstream.msg != NULL)
968 png_error(png_ptr, png_ptr->zstream.msg);
969 else
970 png_error(png_ptr, "zlib error");
971 }
972
973 if (!(png_ptr->zstream.avail_out))
974 {
975 /* write the IDAT and reset the zlib output buffer */
976 png_write_IDAT(png_ptr, png_ptr->zbuf,
977 png_ptr->zbuf_size);
978 png_ptr->zstream.next_out = png_ptr->zbuf;
979 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
980 wrote_IDAT = 1;
981 }
982 } while(wrote_IDAT == 1);
983
984 /* If there is any data left to be output, write it into a new IDAT */
985 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
986 {
987 /* write the IDAT and reset the zlib output buffer */
988 png_write_IDAT(png_ptr, png_ptr->zbuf,
989 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
990 png_ptr->zstream.next_out = png_ptr->zbuf;
991 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
992 }
993 png_ptr->flush_rows = 0;
994 png_flush(png_ptr);
995 }
996 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
997
998 /* free all memory used by the write */
999 void PNGAPI
png_destroy_write_struct(png_structpp png_ptr_ptr,png_infopp info_ptr_ptr)1000 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1001 {
1002 png_structp png_ptr = NULL;
1003 png_infop info_ptr = NULL;
1004 #ifdef PNG_USER_MEM_SUPPORTED
1005 png_free_ptr free_fn = NULL;
1006 png_voidp mem_ptr = NULL;
1007 #endif
1008
1009 png_debug(1, "in png_destroy_write_struct\n");
1010 if (png_ptr_ptr != NULL)
1011 {
1012 png_ptr = *png_ptr_ptr;
1013 #ifdef PNG_USER_MEM_SUPPORTED
1014 free_fn = png_ptr->free_fn;
1015 mem_ptr = png_ptr->mem_ptr;
1016 #endif
1017 }
1018
1019 if (info_ptr_ptr != NULL)
1020 info_ptr = *info_ptr_ptr;
1021
1022 if (info_ptr != NULL)
1023 {
1024 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1025
1026 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1027 if (png_ptr->num_chunk_list)
1028 {
1029 png_free(png_ptr, png_ptr->chunk_list);
1030 png_ptr->chunk_list=NULL;
1031 png_ptr->num_chunk_list=0;
1032 }
1033 #endif
1034
1035 #ifdef PNG_USER_MEM_SUPPORTED
1036 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1037 (png_voidp)mem_ptr);
1038 #else
1039 png_destroy_struct((png_voidp)info_ptr);
1040 #endif
1041 *info_ptr_ptr = NULL;
1042 }
1043
1044 if (png_ptr != NULL)
1045 {
1046 png_write_destroy(png_ptr);
1047 #ifdef PNG_USER_MEM_SUPPORTED
1048 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1049 (png_voidp)mem_ptr);
1050 #else
1051 png_destroy_struct((png_voidp)png_ptr);
1052 #endif
1053 *png_ptr_ptr = NULL;
1054 }
1055 }
1056
1057
1058 /* Free any memory used in png_ptr struct (old method) */
1059 void /* PRIVATE */
png_write_destroy(png_structp png_ptr)1060 png_write_destroy(png_structp png_ptr)
1061 {
1062 #ifdef PNG_SETJMP_SUPPORTED
1063 jmp_buf tmp_jmp; /* save jump buffer */
1064 #endif
1065 png_error_ptr error_fn;
1066 png_error_ptr warning_fn;
1067 png_voidp error_ptr;
1068 #ifdef PNG_USER_MEM_SUPPORTED
1069 png_free_ptr free_fn;
1070 #endif
1071
1072 png_debug(1, "in png_write_destroy\n");
1073 /* free any memory zlib uses */
1074 deflateEnd(&png_ptr->zstream);
1075
1076 /* free our memory. png_free checks NULL for us. */
1077 png_free(png_ptr, png_ptr->zbuf);
1078 png_free(png_ptr, png_ptr->row_buf);
1079 png_free(png_ptr, png_ptr->prev_row);
1080 png_free(png_ptr, png_ptr->sub_row);
1081 png_free(png_ptr, png_ptr->up_row);
1082 png_free(png_ptr, png_ptr->avg_row);
1083 png_free(png_ptr, png_ptr->paeth_row);
1084
1085 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1086 png_free(png_ptr, png_ptr->time_buffer);
1087 #endif
1088
1089 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1090 png_free(png_ptr, png_ptr->prev_filters);
1091 png_free(png_ptr, png_ptr->filter_weights);
1092 png_free(png_ptr, png_ptr->inv_filter_weights);
1093 png_free(png_ptr, png_ptr->filter_costs);
1094 png_free(png_ptr, png_ptr->inv_filter_costs);
1095 #endif
1096
1097 #ifdef PNG_SETJMP_SUPPORTED
1098 /* reset structure */
1099 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
1100 #endif
1101
1102 error_fn = png_ptr->error_fn;
1103 warning_fn = png_ptr->warning_fn;
1104 error_ptr = png_ptr->error_ptr;
1105 #ifdef PNG_USER_MEM_SUPPORTED
1106 free_fn = png_ptr->free_fn;
1107 #endif
1108
1109 png_memset(png_ptr, 0, png_sizeof (png_struct));
1110
1111 png_ptr->error_fn = error_fn;
1112 png_ptr->warning_fn = warning_fn;
1113 png_ptr->error_ptr = error_ptr;
1114 #ifdef PNG_USER_MEM_SUPPORTED
1115 png_ptr->free_fn = free_fn;
1116 #endif
1117
1118 #ifdef PNG_SETJMP_SUPPORTED
1119 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1120 #endif
1121 }
1122
1123 /* Allow the application to select one or more row filters to use. */
1124 void PNGAPI
png_set_filter(png_structp png_ptr,int method,int filters)1125 png_set_filter(png_structp png_ptr, int method, int filters)
1126 {
1127 png_debug(1, "in png_set_filter\n");
1128 if (png_ptr == NULL)
1129 return;
1130 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1131 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1132 (method == PNG_INTRAPIXEL_DIFFERENCING))
1133 method = PNG_FILTER_TYPE_BASE;
1134 #endif
1135 if (method == PNG_FILTER_TYPE_BASE)
1136 {
1137 switch (filters & (PNG_ALL_FILTERS | 0x07))
1138 {
1139 #ifndef PNG_NO_WRITE_FILTER
1140 case 5:
1141 case 6:
1142 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1143 #endif /* PNG_NO_WRITE_FILTER */
1144 case PNG_FILTER_VALUE_NONE:
1145 png_ptr->do_filter=PNG_FILTER_NONE; break;
1146 #ifndef PNG_NO_WRITE_FILTER
1147 case PNG_FILTER_VALUE_SUB:
1148 png_ptr->do_filter=PNG_FILTER_SUB; break;
1149 case PNG_FILTER_VALUE_UP:
1150 png_ptr->do_filter=PNG_FILTER_UP; break;
1151 case PNG_FILTER_VALUE_AVG:
1152 png_ptr->do_filter=PNG_FILTER_AVG; break;
1153 case PNG_FILTER_VALUE_PAETH:
1154 png_ptr->do_filter=PNG_FILTER_PAETH; break;
1155 default: png_ptr->do_filter = (png_byte)filters; break;
1156 #else
1157 default: png_warning(png_ptr, "Unknown row filter for method 0");
1158 #endif /* PNG_NO_WRITE_FILTER */
1159 }
1160
1161 /* If we have allocated the row_buf, this means we have already started
1162 * with the image and we should have allocated all of the filter buffers
1163 * that have been selected. If prev_row isn't already allocated, then
1164 * it is too late to start using the filters that need it, since we
1165 * will be missing the data in the previous row. If an application
1166 * wants to start and stop using particular filters during compression,
1167 * it should start out with all of the filters, and then add and
1168 * remove them after the start of compression.
1169 */
1170 if (png_ptr->row_buf != NULL)
1171 {
1172 #ifndef PNG_NO_WRITE_FILTER
1173 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1174 {
1175 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1176 (png_ptr->rowbytes + 1));
1177 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1178 }
1179
1180 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1181 {
1182 if (png_ptr->prev_row == NULL)
1183 {
1184 png_warning(png_ptr, "Can't add Up filter after starting");
1185 png_ptr->do_filter &= ~PNG_FILTER_UP;
1186 }
1187 else
1188 {
1189 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1190 (png_ptr->rowbytes + 1));
1191 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1192 }
1193 }
1194
1195 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1196 {
1197 if (png_ptr->prev_row == NULL)
1198 {
1199 png_warning(png_ptr, "Can't add Average filter after starting");
1200 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1201 }
1202 else
1203 {
1204 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1205 (png_ptr->rowbytes + 1));
1206 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1207 }
1208 }
1209
1210 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1211 png_ptr->paeth_row == NULL)
1212 {
1213 if (png_ptr->prev_row == NULL)
1214 {
1215 png_warning(png_ptr, "Can't add Paeth filter after starting");
1216 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1217 }
1218 else
1219 {
1220 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1221 (png_ptr->rowbytes + 1));
1222 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1223 }
1224 }
1225
1226 if (png_ptr->do_filter == PNG_NO_FILTERS)
1227 #endif /* PNG_NO_WRITE_FILTER */
1228 png_ptr->do_filter = PNG_FILTER_NONE;
1229 }
1230 }
1231 else
1232 png_error(png_ptr, "Unknown custom filter method");
1233 }
1234
1235 /* This allows us to influence the way in which libpng chooses the "best"
1236 * filter for the current scanline. While the "minimum-sum-of-absolute-
1237 * differences metric is relatively fast and effective, there is some
1238 * question as to whether it can be improved upon by trying to keep the
1239 * filtered data going to zlib more consistent, hopefully resulting in
1240 * better compression.
1241 */
1242 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1243 void PNGAPI
png_set_filter_heuristics(png_structp png_ptr,int heuristic_method,int num_weights,png_doublep filter_weights,png_doublep filter_costs)1244 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1245 int num_weights, png_doublep filter_weights,
1246 png_doublep filter_costs)
1247 {
1248 int i;
1249
1250 png_debug(1, "in png_set_filter_heuristics\n");
1251 if (png_ptr == NULL)
1252 return;
1253 if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1254 {
1255 png_warning(png_ptr, "Unknown filter heuristic method");
1256 return;
1257 }
1258
1259 if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1260 {
1261 heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1262 }
1263
1264 if (num_weights < 0 || filter_weights == NULL ||
1265 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1266 {
1267 num_weights = 0;
1268 }
1269
1270 png_ptr->num_prev_filters = (png_byte)num_weights;
1271 png_ptr->heuristic_method = (png_byte)heuristic_method;
1272
1273 if (num_weights > 0)
1274 {
1275 if (png_ptr->prev_filters == NULL)
1276 {
1277 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1278 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1279
1280 /* To make sure that the weighting starts out fairly */
1281 for (i = 0; i < num_weights; i++)
1282 {
1283 png_ptr->prev_filters[i] = 255;
1284 }
1285 }
1286
1287 if (png_ptr->filter_weights == NULL)
1288 {
1289 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1290 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1291
1292 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1293 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1294 for (i = 0; i < num_weights; i++)
1295 {
1296 png_ptr->inv_filter_weights[i] =
1297 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1298 }
1299 }
1300
1301 for (i = 0; i < num_weights; i++)
1302 {
1303 if (filter_weights[i] < 0.0)
1304 {
1305 png_ptr->inv_filter_weights[i] =
1306 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1307 }
1308 else
1309 {
1310 png_ptr->inv_filter_weights[i] =
1311 (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1312 png_ptr->filter_weights[i] =
1313 (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1314 }
1315 }
1316 }
1317
1318 /* If, in the future, there are other filter methods, this would
1319 * need to be based on png_ptr->filter.
1320 */
1321 if (png_ptr->filter_costs == NULL)
1322 {
1323 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1324 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1325
1326 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1327 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1328
1329 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1330 {
1331 png_ptr->inv_filter_costs[i] =
1332 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1333 }
1334 }
1335
1336 /* Here is where we set the relative costs of the different filters. We
1337 * should take the desired compression level into account when setting
1338 * the costs, so that Paeth, for instance, has a high relative cost at low
1339 * compression levels, while it has a lower relative cost at higher
1340 * compression settings. The filter types are in order of increasing
1341 * relative cost, so it would be possible to do this with an algorithm.
1342 */
1343 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1344 {
1345 if (filter_costs == NULL || filter_costs[i] < 0.0)
1346 {
1347 png_ptr->inv_filter_costs[i] =
1348 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1349 }
1350 else if (filter_costs[i] >= 1.0)
1351 {
1352 png_ptr->inv_filter_costs[i] =
1353 (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1354 png_ptr->filter_costs[i] =
1355 (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1356 }
1357 }
1358 }
1359 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1360
1361 void PNGAPI
png_set_compression_level(png_structp png_ptr,int level)1362 png_set_compression_level(png_structp png_ptr, int level)
1363 {
1364 png_debug(1, "in png_set_compression_level\n");
1365 if (png_ptr == NULL)
1366 return;
1367 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1368 png_ptr->zlib_level = level;
1369 }
1370
1371 void PNGAPI
png_set_compression_mem_level(png_structp png_ptr,int mem_level)1372 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1373 {
1374 png_debug(1, "in png_set_compression_mem_level\n");
1375 if (png_ptr == NULL)
1376 return;
1377 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1378 png_ptr->zlib_mem_level = mem_level;
1379 }
1380
1381 void PNGAPI
png_set_compression_strategy(png_structp png_ptr,int strategy)1382 png_set_compression_strategy(png_structp png_ptr, int strategy)
1383 {
1384 png_debug(1, "in png_set_compression_strategy\n");
1385 if (png_ptr == NULL)
1386 return;
1387 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1388 png_ptr->zlib_strategy = strategy;
1389 }
1390
1391 void PNGAPI
png_set_compression_window_bits(png_structp png_ptr,int window_bits)1392 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1393 {
1394 if (png_ptr == NULL)
1395 return;
1396 if (window_bits > 15)
1397 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1398 else if (window_bits < 8)
1399 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1400 #ifndef WBITS_8_OK
1401 /* avoid libpng bug with 256-byte windows */
1402 if (window_bits == 8)
1403 {
1404 png_warning(png_ptr, "Compression window is being reset to 512");
1405 window_bits=9;
1406 }
1407 #endif
1408 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1409 png_ptr->zlib_window_bits = window_bits;
1410 }
1411
1412 void PNGAPI
png_set_compression_method(png_structp png_ptr,int method)1413 png_set_compression_method(png_structp png_ptr, int method)
1414 {
1415 png_debug(1, "in png_set_compression_method\n");
1416 if (png_ptr == NULL)
1417 return;
1418 if (method != 8)
1419 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1420 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1421 png_ptr->zlib_method = method;
1422 }
1423
1424 void PNGAPI
png_set_write_status_fn(png_structp png_ptr,png_write_status_ptr write_row_fn)1425 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1426 {
1427 if (png_ptr == NULL)
1428 return;
1429 png_ptr->write_row_fn = write_row_fn;
1430 }
1431
1432 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1433 void PNGAPI
png_set_write_user_transform_fn(png_structp png_ptr,png_user_transform_ptr write_user_transform_fn)1434 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1435 write_user_transform_fn)
1436 {
1437 png_debug(1, "in png_set_write_user_transform_fn\n");
1438 if (png_ptr == NULL)
1439 return;
1440 png_ptr->transformations |= PNG_USER_TRANSFORM;
1441 png_ptr->write_user_transform_fn = write_user_transform_fn;
1442 }
1443 #endif
1444
1445
1446 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1447 void PNGAPI
png_write_png(png_structp png_ptr,png_infop info_ptr,int transforms,voidp params)1448 png_write_png(png_structp png_ptr, png_infop info_ptr,
1449 int transforms, voidp params)
1450 {
1451 if (png_ptr == NULL || info_ptr == NULL)
1452 return;
1453 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1454 /* invert the alpha channel from opacity to transparency */
1455 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1456 png_set_invert_alpha(png_ptr);
1457 #endif
1458
1459 /* Write the file header information. */
1460 png_write_info(png_ptr, info_ptr);
1461
1462 /* ------ these transformations don't touch the info structure ------- */
1463
1464 #if defined(PNG_WRITE_INVERT_SUPPORTED)
1465 /* invert monochrome pixels */
1466 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1467 png_set_invert_mono(png_ptr);
1468 #endif
1469
1470 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
1471 /* Shift the pixels up to a legal bit depth and fill in
1472 * as appropriate to correctly scale the image.
1473 */
1474 if ((transforms & PNG_TRANSFORM_SHIFT)
1475 && (info_ptr->valid & PNG_INFO_sBIT))
1476 png_set_shift(png_ptr, &info_ptr->sig_bit);
1477 #endif
1478
1479 #if defined(PNG_WRITE_PACK_SUPPORTED)
1480 /* pack pixels into bytes */
1481 if (transforms & PNG_TRANSFORM_PACKING)
1482 png_set_packing(png_ptr);
1483 #endif
1484
1485 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1486 /* swap location of alpha bytes from ARGB to RGBA */
1487 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1488 png_set_swap_alpha(png_ptr);
1489 #endif
1490
1491 #if defined(PNG_WRITE_FILLER_SUPPORTED)
1492 /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1493 * RGB (4 channels -> 3 channels). The second parameter is not used.
1494 */
1495 if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1496 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1497 #endif
1498
1499 #if defined(PNG_WRITE_BGR_SUPPORTED)
1500 /* flip BGR pixels to RGB */
1501 if (transforms & PNG_TRANSFORM_BGR)
1502 png_set_bgr(png_ptr);
1503 #endif
1504
1505 #if defined(PNG_WRITE_SWAP_SUPPORTED)
1506 /* swap bytes of 16-bit files to most significant byte first */
1507 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1508 png_set_swap(png_ptr);
1509 #endif
1510
1511 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1512 /* swap bits of 1, 2, 4 bit packed pixel formats */
1513 if (transforms & PNG_TRANSFORM_PACKSWAP)
1514 png_set_packswap(png_ptr);
1515 #endif
1516
1517 /* ----------------------- end of transformations ------------------- */
1518
1519 /* write the bits */
1520 if (info_ptr->valid & PNG_INFO_IDAT)
1521 png_write_image(png_ptr, info_ptr->row_pointers);
1522
1523 /* It is REQUIRED to call this to finish writing the rest of the file */
1524 png_write_end(png_ptr, info_ptr);
1525
1526 transforms = transforms; /* quiet compiler warnings */
1527 params = params;
1528 }
1529 #endif
1530 #endif /* PNG_WRITE_SUPPORTED */
1531