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pngwutil.c
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1
2 /* pngwutil.c - utilities to write a PNG file
3 *
4 * Last changed in libpng 1.5.0 [January 6, 2011]
5 * Copyright (c) 1998-2011 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 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
19 /* Place a 32-bit number into a buffer in PNG byte order. We work
20 * with unsigned numbers for convenience, although one supported
21 * ancillary chunk uses signed (two's complement) numbers.
22 */
23 void PNGAPI
24 png_save_uint_32(png_bytep buf, png_uint_32 i)
25 {
26 buf[0] = (png_byte)((i >> 24) & 0xff);
27 buf[1] = (png_byte)((i >> 16) & 0xff);
28 buf[2] = (png_byte)((i >> 8) & 0xff);
29 buf[3] = (png_byte)(i & 0xff);
30 }
31
32 #ifdef PNG_SAVE_INT_32_SUPPORTED
33 /* The png_save_int_32 function assumes integers are stored in two's
34 * complement format. If this isn't the case, then this routine needs to
35 * be modified to write data in two's complement format. Note that,
36 * the following works correctly even if png_int_32 has more than 32 bits
37 * (compare the more complex code required on read for sign extention.)
38 */
39 void PNGAPI
40 png_save_int_32(png_bytep buf, png_int_32 i)
41 {
42 buf[0] = (png_byte)((i >> 24) & 0xff);
43 buf[1] = (png_byte)((i >> 16) & 0xff);
44 buf[2] = (png_byte)((i >> 8) & 0xff);
45 buf[3] = (png_byte)(i & 0xff);
46 }
47 #endif
48
49 /* Place a 16-bit number into a buffer in PNG byte order.
50 * The parameter is declared unsigned int, not png_uint_16,
51 * just to avoid potential problems on pre-ANSI C compilers.
52 */
53 void PNGAPI
54 png_save_uint_16(png_bytep buf, unsigned int i)
55 {
56 buf[0] = (png_byte)((i >> 8) & 0xff);
57 buf[1] = (png_byte)(i & 0xff);
58 }
59 #endif
60
61 /* Simple function to write the signature. If we have already written
62 * the magic bytes of the signature, or more likely, the PNG stream is
63 * being embedded into another stream and doesn't need its own signature,
64 * we should call png_set_sig_bytes() to tell libpng how many of the
65 * bytes have already been written.
66 */
67 void PNGAPI
68 png_write_sig(png_structp png_ptr)
69 {
70 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
71
72 #ifdef PNG_IO_STATE_SUPPORTED
73 /* Inform the I/O callback that the signature is being written */
74 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
75 #endif
76
77 /* Write the rest of the 8 byte signature */
78 png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
79 (png_size_t)(8 - png_ptr->sig_bytes));
80
81 if (png_ptr->sig_bytes < 3)
82 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
83 }
84
85 /* Write a PNG chunk all at once. The type is an array of ASCII characters
86 * representing the chunk name. The array must be at least 4 bytes in
87 * length, and does not need to be null terminated. To be safe, pass the
88 * pre-defined chunk names here, and if you need a new one, define it
89 * where the others are defined. The length is the length of the data.
90 * All the data must be present. If that is not possible, use the
91 * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
92 * functions instead.
93 */
94 void PNGAPI
95 png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name,
96 png_const_bytep data, png_size_t length)
97 {
98 if (png_ptr == NULL)
99 return;
100
101 png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
102 png_write_chunk_data(png_ptr, data, (png_size_t)length);
103 png_write_chunk_end(png_ptr);
104 }
105
106 /* Write the start of a PNG chunk. The type is the chunk type.
107 * The total_length is the sum of the lengths of all the data you will be
108 * passing in png_write_chunk_data().
109 */
110 void PNGAPI
111 png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name,
112 png_uint_32 length)
113 {
114 png_byte buf[8];
115
116 png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
117 (unsigned long)length);
118
119 if (png_ptr == NULL)
120 return;
121
122 #ifdef PNG_IO_STATE_SUPPORTED
123 /* Inform the I/O callback that the chunk header is being written.
124 * PNG_IO_CHUNK_HDR requires a single I/O call.
125 */
126 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
127 #endif
128
129 /* Write the length and the chunk name */
130 png_save_uint_32(buf, length);
131 png_memcpy(buf + 4, chunk_name, 4);
132 png_write_data(png_ptr, buf, (png_size_t)8);
133
134 /* Put the chunk name into png_ptr->chunk_name */
135 png_memcpy(png_ptr->chunk_name, chunk_name, 4);
136
137 /* Reset the crc and run it over the chunk name */
138 png_reset_crc(png_ptr);
139
140 png_calculate_crc(png_ptr, chunk_name, 4);
141
142 #ifdef PNG_IO_STATE_SUPPORTED
143 /* Inform the I/O callback that chunk data will (possibly) be written.
144 * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
145 */
146 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
147 #endif
148 }
149
150 /* Write the data of a PNG chunk started with png_write_chunk_start().
151 * Note that multiple calls to this function are allowed, and that the
152 * sum of the lengths from these calls *must* add up to the total_length
153 * given to png_write_chunk_start().
154 */
155 void PNGAPI
156 png_write_chunk_data(png_structp png_ptr, png_const_bytep data,
157 png_size_t length)
158 {
159 /* Write the data, and run the CRC over it */
160 if (png_ptr == NULL)
161 return;
162
163 if (data != NULL && length > 0)
164 {
165 png_write_data(png_ptr, data, length);
166
167 /* Update the CRC after writing the data,
168 * in case that the user I/O routine alters it.
169 */
170 png_calculate_crc(png_ptr, data, length);
171 }
172 }
173
174 /* Finish a chunk started with png_write_chunk_start(). */
175 void PNGAPI
176 png_write_chunk_end(png_structp png_ptr)
177 {
178 png_byte buf[4];
179
180 if (png_ptr == NULL) return;
181
182 #ifdef PNG_IO_STATE_SUPPORTED
183 /* Inform the I/O callback that the chunk CRC is being written.
184 * PNG_IO_CHUNK_CRC requires a single I/O function call.
185 */
186 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
187 #endif
188
189 /* Write the crc in a single operation */
190 png_save_uint_32(buf, png_ptr->crc);
191
192 png_write_data(png_ptr, buf, (png_size_t)4);
193 }
194
195 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
196 /* This pair of functions encapsulates the operation of (a) compressing a
197 * text string, and (b) issuing it later as a series of chunk data writes.
198 * The compression_state structure is shared context for these functions
199 * set up by the caller in order to make the whole mess thread-safe.
200 */
201
202 typedef struct
203 {
204 png_const_bytep input; /* The uncompressed input data */
205 png_size_t input_len; /* Its length */
206 int num_output_ptr; /* Number of output pointers used */
207 int max_output_ptr; /* Size of output_ptr */
208 png_bytep *output_ptr; /* Array of pointers to output */
209 } compression_state;
210
211 /* Compress given text into storage in the png_ptr structure */
212 static int /* PRIVATE */
213 png_text_compress(png_structp png_ptr,
214 png_const_charp text, png_size_t text_len, int compression,
215 compression_state *comp)
216 {
217 int ret;
218
219 comp->num_output_ptr = 0;
220 comp->max_output_ptr = 0;
221 comp->output_ptr = NULL;
222 comp->input = NULL;
223 comp->input_len = 0;
224
225 /* We may just want to pass the text right through */
226 if (compression == PNG_TEXT_COMPRESSION_NONE)
227 {
228 comp->input = (png_const_bytep)text;
229 comp->input_len = text_len;
230 return((int)text_len);
231 }
232
233 if (compression >= PNG_TEXT_COMPRESSION_LAST)
234 {
235 #ifdef PNG_CONSOLE_IO_SUPPORTED
236 char msg[50];
237 png_snprintf(msg, 50, "Unknown compression type %d", compression);
238 png_warning(png_ptr, msg);
239 #else
240 png_warning(png_ptr, "Unknown compression type");
241 #endif
242 }
243
244 /* We can't write the chunk until we find out how much data we have,
245 * which means we need to run the compressor first and save the
246 * output. This shouldn't be a problem, as the vast majority of
247 * comments should be reasonable, but we will set up an array of
248 * malloc'd pointers to be sure.
249 *
250 * If we knew the application was well behaved, we could simplify this
251 * greatly by assuming we can always malloc an output buffer large
252 * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
253 * and malloc this directly. The only time this would be a bad idea is
254 * if we can't malloc more than 64K and we have 64K of random input
255 * data, or if the input string is incredibly large (although this
256 * wouldn't cause a failure, just a slowdown due to swapping).
257 */
258
259 /* Set up the compression buffers */
260 /* TODO: the following cast hides a potential overflow problem. */
261 png_ptr->zstream.avail_in = (uInt)text_len;
262 /* NOTE: assume zlib doesn't overwrite the input */
263 png_ptr->zstream.next_in = (Bytef *)text;
264 png_ptr->zstream.avail_out = png_ptr->zbuf_size;
265 png_ptr->zstream.next_out = png_ptr->zbuf;
266
267 /* This is the same compression loop as in png_write_row() */
268 do
269 {
270 /* Compress the data */
271 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
272
273 if (ret != Z_OK)
274 {
275 /* Error */
276 if (png_ptr->zstream.msg != NULL)
277 png_error(png_ptr, png_ptr->zstream.msg);
278
279 else
280 png_error(png_ptr, "zlib error");
281 }
282
283 /* Check to see if we need more room */
284 if (!(png_ptr->zstream.avail_out))
285 {
286 /* Make sure the output array has room */
287 if (comp->num_output_ptr >= comp->max_output_ptr)
288 {
289 int old_max;
290
291 old_max = comp->max_output_ptr;
292 comp->max_output_ptr = comp->num_output_ptr + 4;
293 if (comp->output_ptr != NULL)
294 {
295 png_bytepp old_ptr;
296
297 old_ptr = comp->output_ptr;
298
299 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
300 (png_alloc_size_t)
301 (comp->max_output_ptr * png_sizeof(png_charpp)));
302
303 png_memcpy(comp->output_ptr, old_ptr, old_max
304 * png_sizeof(png_charp));
305
306 png_free(png_ptr, old_ptr);
307 }
308 else
309 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
310 (png_alloc_size_t)
311 (comp->max_output_ptr * png_sizeof(png_charp)));
312 }
313
314 /* Save the data */
315 comp->output_ptr[comp->num_output_ptr] =
316 (png_bytep)png_malloc(png_ptr,
317 (png_alloc_size_t)png_ptr->zbuf_size);
318
319 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
320 png_ptr->zbuf_size);
321
322 comp->num_output_ptr++;
323
324 /* and reset the buffer */
325 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
326 png_ptr->zstream.next_out = png_ptr->zbuf;
327 }
328 /* Continue until we don't have any more to compress */
329 } while (png_ptr->zstream.avail_in);
330
331 /* Finish the compression */
332 do
333 {
334 /* Tell zlib we are finished */
335 ret = deflate(&png_ptr->zstream, Z_FINISH);
336
337 if (ret == Z_OK)
338 {
339 /* Check to see if we need more room */
340 if (!(png_ptr->zstream.avail_out))
341 {
342 /* Check to make sure our output array has room */
343 if (comp->num_output_ptr >= comp->max_output_ptr)
344 {
345 int old_max;
346
347 old_max = comp->max_output_ptr;
348 comp->max_output_ptr = comp->num_output_ptr + 4;
349 if (comp->output_ptr != NULL)
350 {
351 png_bytepp old_ptr;
352
353 old_ptr = comp->output_ptr;
354
355 /* This could be optimized to realloc() */
356 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
357 (png_alloc_size_t)(comp->max_output_ptr *
358 png_sizeof(png_charp)));
359
360 png_memcpy(comp->output_ptr, old_ptr,
361 old_max * png_sizeof(png_charp));
362
363 png_free(png_ptr, old_ptr);
364 }
365
366 else
367 comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
368 (png_alloc_size_t)(comp->max_output_ptr *
369 png_sizeof(png_charp)));
370 }
371
372 /* Save the data */
373 comp->output_ptr[comp->num_output_ptr] =
374 (png_bytep)png_malloc(png_ptr,
375 (png_alloc_size_t)png_ptr->zbuf_size);
376
377 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
378 png_ptr->zbuf_size);
379
380 comp->num_output_ptr++;
381
382 /* and reset the buffer pointers */
383 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
384 png_ptr->zstream.next_out = png_ptr->zbuf;
385 }
386 }
387 else if (ret != Z_STREAM_END)
388 {
389 /* We got an error */
390 if (png_ptr->zstream.msg != NULL)
391 png_error(png_ptr, png_ptr->zstream.msg);
392
393 else
394 png_error(png_ptr, "zlib error");
395 }
396 } while (ret != Z_STREAM_END);
397
398 /* Text length is number of buffers plus last buffer */
399 text_len = png_ptr->zbuf_size * comp->num_output_ptr;
400
401 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
402 text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
403
404 return((int)text_len);
405 }
406
407 /* Ship the compressed text out via chunk writes */
408 static void /* PRIVATE */
409 png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
410 {
411 int i;
412
413 /* Handle the no-compression case */
414 if (comp->input)
415 {
416 png_write_chunk_data(png_ptr, comp->input, comp->input_len);
417
418 return;
419 }
420
421 /* Write saved output buffers, if any */
422 for (i = 0; i < comp->num_output_ptr; i++)
423 {
424 png_write_chunk_data(png_ptr, comp->output_ptr[i],
425 (png_size_t)png_ptr->zbuf_size);
426
427 png_free(png_ptr, comp->output_ptr[i]);
428 }
429
430 if (comp->max_output_ptr != 0)
431 png_free(png_ptr, comp->output_ptr);
432
433 /* Write anything left in zbuf */
434 if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
435 png_write_chunk_data(png_ptr, png_ptr->zbuf,
436 (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
437
438 /* Reset zlib for another zTXt/iTXt or image data */
439 deflateReset(&png_ptr->zstream);
440 png_ptr->zstream.data_type = Z_BINARY;
441 }
442 #endif
443
444 /* Write the IHDR chunk, and update the png_struct with the necessary
445 * information. Note that the rest of this code depends upon this
446 * information being correct.
447 */
448 void /* PRIVATE */
449 png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
450 int bit_depth, int color_type, int compression_type, int filter_type,
451 int interlace_type)
452 {
453 PNG_IHDR;
454 int ret;
455
456 png_byte buf[13]; /* Buffer to store the IHDR info */
457
458 png_debug(1, "in png_write_IHDR");
459
460 /* Check that we have valid input data from the application info */
461 switch (color_type)
462 {
463 case PNG_COLOR_TYPE_GRAY:
464 switch (bit_depth)
465 {
466 case 1:
467 case 2:
468 case 4:
469 case 8:
470 #ifdef PNG_WRITE_16BIT_SUPPORTED
471 case 16:
472 #endif
473 png_ptr->channels = 1; break;
474
475 default:
476 png_error(png_ptr,
477 "Invalid bit depth for grayscale image");
478 }
479 break;
480
481 case PNG_COLOR_TYPE_RGB:
482 #ifdef PNG_WRITE_16BIT_SUPPORTED
483 if (bit_depth != 8 && bit_depth != 16)
484 #else
485 if (bit_depth != 8)
486 #endif
487 png_error(png_ptr, "Invalid bit depth for RGB image");
488
489 png_ptr->channels = 3;
490 break;
491
492 case PNG_COLOR_TYPE_PALETTE:
493 switch (bit_depth)
494 {
495 case 1:
496 case 2:
497 case 4:
498 case 8:
499 png_ptr->channels = 1;
500 break;
501
502 default:
503 png_error(png_ptr, "Invalid bit depth for paletted image");
504 }
505 break;
506
507 case PNG_COLOR_TYPE_GRAY_ALPHA:
508 if (bit_depth != 8 && bit_depth != 16)
509 png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
510
511 png_ptr->channels = 2;
512 break;
513
514 case PNG_COLOR_TYPE_RGB_ALPHA:
515 #ifdef PNG_WRITE_16BIT_SUPPORTED
516 if (bit_depth != 8 && bit_depth != 16)
517 #else
518 if (bit_depth != 8)
519 #endif
520 png_error(png_ptr, "Invalid bit depth for RGBA image");
521
522 png_ptr->channels = 4;
523 break;
524
525 default:
526 png_error(png_ptr, "Invalid image color type specified");
527 }
528
529 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
530 {
531 png_warning(png_ptr, "Invalid compression type specified");
532 compression_type = PNG_COMPRESSION_TYPE_BASE;
533 }
534
535 /* Write filter_method 64 (intrapixel differencing) only if
536 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
537 * 2. Libpng did not write a PNG signature (this filter_method is only
538 * used in PNG datastreams that are embedded in MNG datastreams) and
539 * 3. The application called png_permit_mng_features with a mask that
540 * included PNG_FLAG_MNG_FILTER_64 and
541 * 4. The filter_method is 64 and
542 * 5. The color_type is RGB or RGBA
543 */
544 if (
545 #ifdef PNG_MNG_FEATURES_SUPPORTED
546 !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
547 ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
548 (color_type == PNG_COLOR_TYPE_RGB ||
549 color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
550 (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
551 #endif
552 filter_type != PNG_FILTER_TYPE_BASE)
553 {
554 png_warning(png_ptr, "Invalid filter type specified");
555 filter_type = PNG_FILTER_TYPE_BASE;
556 }
557
558 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
559 if (interlace_type != PNG_INTERLACE_NONE &&
560 interlace_type != PNG_INTERLACE_ADAM7)
561 {
562 png_warning(png_ptr, "Invalid interlace type specified");
563 interlace_type = PNG_INTERLACE_ADAM7;
564 }
565 #else
566 interlace_type=PNG_INTERLACE_NONE;
567 #endif
568
569 /* Save the relevent information */
570 png_ptr->bit_depth = (png_byte)bit_depth;
571 png_ptr->color_type = (png_byte)color_type;
572 png_ptr->interlaced = (png_byte)interlace_type;
573 #ifdef PNG_MNG_FEATURES_SUPPORTED
574 png_ptr->filter_type = (png_byte)filter_type;
575 #endif
576 png_ptr->compression_type = (png_byte)compression_type;
577 png_ptr->width = width;
578 png_ptr->height = height;
579
580 png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
581 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
582 /* Set the usr info, so any transformations can modify it */
583 png_ptr->usr_width = png_ptr->width;
584 png_ptr->usr_bit_depth = png_ptr->bit_depth;
585 png_ptr->usr_channels = png_ptr->channels;
586
587 /* Pack the header information into the buffer */
588 png_save_uint_32(buf, width);
589 png_save_uint_32(buf + 4, height);
590 buf[8] = (png_byte)bit_depth;
591 buf[9] = (png_byte)color_type;
592 buf[10] = (png_byte)compression_type;
593 buf[11] = (png_byte)filter_type;
594 buf[12] = (png_byte)interlace_type;
595
596 /* Write the chunk */
597 png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
598
599 /* Initialize zlib with PNG info */
600 png_ptr->zstream.zalloc = png_zalloc;
601 png_ptr->zstream.zfree = png_zfree;
602 png_ptr->zstream.opaque = (voidpf)png_ptr;
603
604 if (!(png_ptr->do_filter))
605 {
606 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
607 png_ptr->bit_depth < 8)
608 png_ptr->do_filter = PNG_FILTER_NONE;
609
610 else
611 png_ptr->do_filter = PNG_ALL_FILTERS;
612 }
613
614 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
615 {
616 if (png_ptr->do_filter != PNG_FILTER_NONE)
617 png_ptr->zlib_strategy = Z_FILTERED;
618
619 else
620 png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
621 }
622
623 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
624 png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
625
626 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
627 png_ptr->zlib_mem_level = 8;
628
629 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
630 png_ptr->zlib_window_bits = 15;
631
632 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
633 png_ptr->zlib_method = 8;
634
635 ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
636 png_ptr->zlib_method, png_ptr->zlib_window_bits,
637 png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
638
639 if (ret != Z_OK)
640 {
641 if (ret == Z_VERSION_ERROR)
642 png_error(png_ptr,
643 "zlib failed to initialize compressor -- version error");
644
645 if (ret == Z_STREAM_ERROR)
646 png_error(png_ptr,
647 "zlib failed to initialize compressor -- stream error");
648
649 if (ret == Z_MEM_ERROR)
650 png_error(png_ptr,
651 "zlib failed to initialize compressor -- mem error");
652
653 png_error(png_ptr, "zlib failed to initialize compressor");
654 }
655
656 png_ptr->zstream.next_out = png_ptr->zbuf;
657 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
658 /* libpng is not interested in zstream.data_type, so set it
659 * to a predefined value, to avoid its evaluation inside zlib
660 */
661 png_ptr->zstream.data_type = Z_BINARY;
662
663 png_ptr->mode = PNG_HAVE_IHDR;
664 }
665
666 /* Write the palette. We are careful not to trust png_color to be in the
667 * correct order for PNG, so people can redefine it to any convenient
668 * structure.
669 */
670 void /* PRIVATE */
671 png_write_PLTE(png_structp png_ptr, png_const_colorp palette,
672 png_uint_32 num_pal)
673 {
674 PNG_PLTE;
675 png_uint_32 i;
676 png_const_colorp pal_ptr;
677 png_byte buf[3];
678
679 png_debug(1, "in png_write_PLTE");
680
681 if ((
682 #ifdef PNG_MNG_FEATURES_SUPPORTED
683 !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
684 #endif
685 num_pal == 0) || num_pal > 256)
686 {
687 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
688 {
689 png_error(png_ptr, "Invalid number of colors in palette");
690 }
691
692 else
693 {
694 png_warning(png_ptr, "Invalid number of colors in palette");
695 return;
696 }
697 }
698
699 if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
700 {
701 png_warning(png_ptr,
702 "Ignoring request to write a PLTE chunk in grayscale PNG");
703
704 return;
705 }
706
707 png_ptr->num_palette = (png_uint_16)num_pal;
708 png_debug1(3, "num_palette = %d", png_ptr->num_palette);
709
710 png_write_chunk_start(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
711 #ifdef PNG_POINTER_INDEXING_SUPPORTED
712
713 for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
714 {
715 buf[0] = pal_ptr->red;
716 buf[1] = pal_ptr->green;
717 buf[2] = pal_ptr->blue;
718 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
719 }
720
721 #else
722 /* This is a little slower but some buggy compilers need to do this
723 * instead
724 */
725 pal_ptr=palette;
726
727 for (i = 0; i < num_pal; i++)
728 {
729 buf[0] = pal_ptr[i].red;
730 buf[1] = pal_ptr[i].green;
731 buf[2] = pal_ptr[i].blue;
732 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
733 }
734
735 #endif
736 png_write_chunk_end(png_ptr);
737 png_ptr->mode |= PNG_HAVE_PLTE;
738 }
739
740 /* Write an IDAT chunk */
741 void /* PRIVATE */
742 png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
743 {
744 PNG_IDAT;
745
746 png_debug(1, "in png_write_IDAT");
747
748 /* Optimize the CMF field in the zlib stream. */
749 /* This hack of the zlib stream is compliant to the stream specification. */
750 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
751 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
752 {
753 unsigned int z_cmf = data[0]; /* zlib compression method and flags */
754 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
755 {
756 /* Avoid memory underflows and multiplication overflows.
757 *
758 * The conditions below are practically always satisfied;
759 * however, they still must be checked.
760 */
761 if (length >= 2 &&
762 png_ptr->height < 16384 && png_ptr->width < 16384)
763 {
764 png_uint_32 uncompressed_idat_size = png_ptr->height *
765 ((png_ptr->width *
766 png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
767 unsigned int z_cinfo = z_cmf >> 4;
768 unsigned int half_z_window_size = 1 << (z_cinfo + 7);
769 while (uncompressed_idat_size <= half_z_window_size &&
770 half_z_window_size >= 256)
771 {
772 z_cinfo--;
773 half_z_window_size >>= 1;
774 }
775
776 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
777
778 if (data[0] != z_cmf)
779 {
780 int tmp;
781 data[0] = (png_byte)z_cmf;
782 tmp = data[1] & 0xe0;
783 tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
784 data[1] = (png_byte)tmp;
785 }
786 }
787 }
788
789 else
790 png_error(png_ptr,
791 "Invalid zlib compression method or flags in IDAT");
792 }
793
794 png_write_chunk(png_ptr, png_IDAT, data, length);
795 png_ptr->mode |= PNG_HAVE_IDAT;
796 }
797
798 /* Write an IEND chunk */
799 void /* PRIVATE */
800 png_write_IEND(png_structp png_ptr)
801 {
802 PNG_IEND;
803
804 png_debug(1, "in png_write_IEND");
805
806 png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
807 png_ptr->mode |= PNG_HAVE_IEND;
808 }
809
810 #ifdef PNG_WRITE_gAMA_SUPPORTED
811 /* Write a gAMA chunk */
812 void /* PRIVATE */
813 png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
814 {
815 PNG_gAMA;
816 png_byte buf[4];
817
818 png_debug(1, "in png_write_gAMA");
819
820 /* file_gamma is saved in 1/100,000ths */
821 png_save_uint_32(buf, (png_uint_32)file_gamma);
822 png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
823 }
824 #endif
825
826 #ifdef PNG_WRITE_sRGB_SUPPORTED
827 /* Write a sRGB chunk */
828 void /* PRIVATE */
829 png_write_sRGB(png_structp png_ptr, int srgb_intent)
830 {
831 PNG_sRGB;
832 png_byte buf[1];
833
834 png_debug(1, "in png_write_sRGB");
835
836 if (srgb_intent >= PNG_sRGB_INTENT_LAST)
837 png_warning(png_ptr,
838 "Invalid sRGB rendering intent specified");
839
840 buf[0]=(png_byte)srgb_intent;
841 png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
842 }
843 #endif
844
845 #ifdef PNG_WRITE_iCCP_SUPPORTED
846 /* Write an iCCP chunk */
847 void /* PRIVATE */
848 png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,
849 png_const_charp profile, int profile_len)
850 {
851 PNG_iCCP;
852 png_size_t name_len;
853 png_charp new_name;
854 compression_state comp;
855 int embedded_profile_len = 0;
856
857 png_debug(1, "in png_write_iCCP");
858
859 comp.num_output_ptr = 0;
860 comp.max_output_ptr = 0;
861 comp.output_ptr = NULL;
862 comp.input = NULL;
863 comp.input_len = 0;
864
865 if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0)
866 return;
867
868 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
869 png_warning(png_ptr, "Unknown compression type in iCCP chunk");
870
871 if (profile == NULL)
872 profile_len = 0;
873
874 if (profile_len > 3)
875 embedded_profile_len =
876 ((*( (png_const_bytep)profile ))<<24) |
877 ((*( (png_const_bytep)profile + 1))<<16) |
878 ((*( (png_const_bytep)profile + 2))<< 8) |
879 ((*( (png_const_bytep)profile + 3)) );
880
881 if (embedded_profile_len < 0)
882 {
883 png_warning(png_ptr,
884 "Embedded profile length in iCCP chunk is negative");
885
886 png_free(png_ptr, new_name);
887 return;
888 }
889
890 if (profile_len < embedded_profile_len)
891 {
892 png_warning(png_ptr,
893 "Embedded profile length too large in iCCP chunk");
894
895 png_free(png_ptr, new_name);
896 return;
897 }
898
899 if (profile_len > embedded_profile_len)
900 {
901 png_warning(png_ptr,
902 "Truncating profile to actual length in iCCP chunk");
903
904 profile_len = embedded_profile_len;
905 }
906
907 if (profile_len)
908 profile_len = png_text_compress(png_ptr, profile,
909 (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
910
911 /* Make sure we include the NULL after the name and the compression type */
912 png_write_chunk_start(png_ptr, png_iCCP,
913 (png_uint_32)(name_len + profile_len + 2));
914
915 new_name[name_len + 1] = 0x00;
916
917 png_write_chunk_data(png_ptr, (png_bytep)new_name,
918 (png_size_t)(name_len + 2));
919
920 if (profile_len)
921 png_write_compressed_data_out(png_ptr, &comp);
922
923 png_write_chunk_end(png_ptr);
924 png_free(png_ptr, new_name);
925 }
926 #endif
927
928 #ifdef PNG_WRITE_sPLT_SUPPORTED
929 /* Write a sPLT chunk */
930 void /* PRIVATE */
931 png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette)
932 {
933 PNG_sPLT;
934 png_size_t name_len;
935 png_charp new_name;
936 png_byte entrybuf[10];
937 png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
938 png_size_t palette_size = entry_size * spalette->nentries;
939 png_sPLT_entryp ep;
940 #ifndef PNG_POINTER_INDEXING_SUPPORTED
941 int i;
942 #endif
943
944 png_debug(1, "in png_write_sPLT");
945
946 if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
947 return;
948
949 /* Make sure we include the NULL after the name */
950 png_write_chunk_start(png_ptr, png_sPLT,
951 (png_uint_32)(name_len + 2 + palette_size));
952
953 png_write_chunk_data(png_ptr, (png_bytep)new_name,
954 (png_size_t)(name_len + 1));
955
956 png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
957
958 /* Loop through each palette entry, writing appropriately */
959 #ifdef PNG_POINTER_INDEXING_SUPPORTED
960 for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
961 {
962 if (spalette->depth == 8)
963 {
964 entrybuf[0] = (png_byte)ep->red;
965 entrybuf[1] = (png_byte)ep->green;
966 entrybuf[2] = (png_byte)ep->blue;
967 entrybuf[3] = (png_byte)ep->alpha;
968 png_save_uint_16(entrybuf + 4, ep->frequency);
969 }
970
971 else
972 {
973 png_save_uint_16(entrybuf + 0, ep->red);
974 png_save_uint_16(entrybuf + 2, ep->green);
975 png_save_uint_16(entrybuf + 4, ep->blue);
976 png_save_uint_16(entrybuf + 6, ep->alpha);
977 png_save_uint_16(entrybuf + 8, ep->frequency);
978 }
979
980 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
981 }
982 #else
983 ep=spalette->entries;
984 for (i = 0; i>spalette->nentries; i++)
985 {
986 if (spalette->depth == 8)
987 {
988 entrybuf[0] = (png_byte)ep[i].red;
989 entrybuf[1] = (png_byte)ep[i].green;
990 entrybuf[2] = (png_byte)ep[i].blue;
991 entrybuf[3] = (png_byte)ep[i].alpha;
992 png_save_uint_16(entrybuf + 4, ep[i].frequency);
993 }
994
995 else
996 {
997 png_save_uint_16(entrybuf + 0, ep[i].red);
998 png_save_uint_16(entrybuf + 2, ep[i].green);
999 png_save_uint_16(entrybuf + 4, ep[i].blue);
1000 png_save_uint_16(entrybuf + 6, ep[i].alpha);
1001 png_save_uint_16(entrybuf + 8, ep[i].frequency);
1002 }
1003
1004 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
1005 }
1006 #endif
1007
1008 png_write_chunk_end(png_ptr);
1009 png_free(png_ptr, new_name);
1010 }
1011 #endif
1012
1013 #ifdef PNG_WRITE_sBIT_SUPPORTED
1014 /* Write the sBIT chunk */
1015 void /* PRIVATE */
1016 png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type)
1017 {
1018 PNG_sBIT;
1019 png_byte buf[4];
1020 png_size_t size;
1021
1022 png_debug(1, "in png_write_sBIT");
1023
1024 /* Make sure we don't depend upon the order of PNG_COLOR_8 */
1025 if (color_type & PNG_COLOR_MASK_COLOR)
1026 {
1027 png_byte maxbits;
1028
1029 maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
1030 png_ptr->usr_bit_depth);
1031
1032 if (sbit->red == 0 || sbit->red > maxbits ||
1033 sbit->green == 0 || sbit->green > maxbits ||
1034 sbit->blue == 0 || sbit->blue > maxbits)
1035 {
1036 png_warning(png_ptr, "Invalid sBIT depth specified");
1037 return;
1038 }
1039
1040 buf[0] = sbit->red;
1041 buf[1] = sbit->green;
1042 buf[2] = sbit->blue;
1043 size = 3;
1044 }
1045
1046 else
1047 {
1048 if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
1049 {
1050 png_warning(png_ptr, "Invalid sBIT depth specified");
1051 return;
1052 }
1053
1054 buf[0] = sbit->gray;
1055 size = 1;
1056 }
1057
1058 if (color_type & PNG_COLOR_MASK_ALPHA)
1059 {
1060 if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
1061 {
1062 png_warning(png_ptr, "Invalid sBIT depth specified");
1063 return;
1064 }
1065
1066 buf[size++] = sbit->alpha;
1067 }
1068
1069 png_write_chunk(png_ptr, png_sBIT, buf, size);
1070 }
1071 #endif
1072
1073 #ifdef PNG_WRITE_cHRM_SUPPORTED
1074 /* Write the cHRM chunk */
1075 void /* PRIVATE */
1076 png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
1077 png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
1078 png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
1079 png_fixed_point blue_y)
1080 {
1081 PNG_cHRM;
1082 png_byte buf[32];
1083
1084 png_debug(1, "in png_write_cHRM");
1085
1086 /* Each value is saved in 1/100,000ths */
1087 #ifdef PNG_CHECK_cHRM_SUPPORTED
1088 if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
1089 green_x, green_y, blue_x, blue_y))
1090 #endif
1091 {
1092 png_save_uint_32(buf, (png_uint_32)white_x);
1093 png_save_uint_32(buf + 4, (png_uint_32)white_y);
1094
1095 png_save_uint_32(buf + 8, (png_uint_32)red_x);
1096 png_save_uint_32(buf + 12, (png_uint_32)red_y);
1097
1098 png_save_uint_32(buf + 16, (png_uint_32)green_x);
1099 png_save_uint_32(buf + 20, (png_uint_32)green_y);
1100
1101 png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1102 png_save_uint_32(buf + 28, (png_uint_32)blue_y);
1103
1104 png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);
1105 }
1106 }
1107 #endif
1108
1109 #ifdef PNG_WRITE_tRNS_SUPPORTED
1110 /* Write the tRNS chunk */
1111 void /* PRIVATE */
1112 png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha,
1113 png_const_color_16p tran, int num_trans, int color_type)
1114 {
1115 PNG_tRNS;
1116 png_byte buf[6];
1117
1118 png_debug(1, "in png_write_tRNS");
1119
1120 if (color_type == PNG_COLOR_TYPE_PALETTE)
1121 {
1122 if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
1123 {
1124 png_warning(png_ptr, "Invalid number of transparent colors specified");
1125 return;
1126 }
1127
1128 /* Write the chunk out as it is */
1129 png_write_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans);
1130 }
1131
1132 else if (color_type == PNG_COLOR_TYPE_GRAY)
1133 {
1134 /* One 16 bit value */
1135 if (tran->gray >= (1 << png_ptr->bit_depth))
1136 {
1137 png_warning(png_ptr,
1138 "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1139
1140 return;
1141 }
1142
1143 png_save_uint_16(buf, tran->gray);
1144 png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
1145 }
1146
1147 else if (color_type == PNG_COLOR_TYPE_RGB)
1148 {
1149 /* Three 16 bit values */
1150 png_save_uint_16(buf, tran->red);
1151 png_save_uint_16(buf + 2, tran->green);
1152 png_save_uint_16(buf + 4, tran->blue);
1153 #ifdef PNG_WRITE_16BIT_SUPPORTED
1154 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1155 #else
1156 if (buf[0] | buf[2] | buf[4])
1157 #endif
1158 {
1159 png_warning(png_ptr,
1160 "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1161 return;
1162 }
1163
1164 png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
1165 }
1166
1167 else
1168 {
1169 png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1170 }
1171 }
1172 #endif
1173
1174 #ifdef PNG_WRITE_bKGD_SUPPORTED
1175 /* Write the background chunk */
1176 void /* PRIVATE */
1177 png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type)
1178 {
1179 PNG_bKGD;
1180 png_byte buf[6];
1181
1182 png_debug(1, "in png_write_bKGD");
1183
1184 if (color_type == PNG_COLOR_TYPE_PALETTE)
1185 {
1186 if (
1187 #ifdef PNG_MNG_FEATURES_SUPPORTED
1188 (png_ptr->num_palette ||
1189 (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1190 #endif
1191 back->index >= png_ptr->num_palette)
1192 {
1193 png_warning(png_ptr, "Invalid background palette index");
1194 return;
1195 }
1196
1197 buf[0] = back->index;
1198 png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
1199 }
1200
1201 else if (color_type & PNG_COLOR_MASK_COLOR)
1202 {
1203 png_save_uint_16(buf, back->red);
1204 png_save_uint_16(buf + 2, back->green);
1205 png_save_uint_16(buf + 4, back->blue);
1206 #ifdef PNG_WRITE_16BIT_SUPPORTED
1207 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1208 #else
1209 if (buf[0] | buf[2] | buf[4])
1210 #endif
1211 {
1212 png_warning(png_ptr,
1213 "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1214
1215 return;
1216 }
1217
1218 png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
1219 }
1220
1221 else
1222 {
1223 if (back->gray >= (1 << png_ptr->bit_depth))
1224 {
1225 png_warning(png_ptr,
1226 "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1227
1228 return;
1229 }
1230
1231 png_save_uint_16(buf, back->gray);
1232 png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
1233 }
1234 }
1235 #endif
1236
1237 #ifdef PNG_WRITE_hIST_SUPPORTED
1238 /* Write the histogram */
1239 void /* PRIVATE */
1240 png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist)
1241 {
1242 PNG_hIST;
1243 int i;
1244 png_byte buf[3];
1245
1246 png_debug(1, "in png_write_hIST");
1247
1248 if (num_hist > (int)png_ptr->num_palette)
1249 {
1250 png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
1251 png_ptr->num_palette);
1252
1253 png_warning(png_ptr, "Invalid number of histogram entries specified");
1254 return;
1255 }
1256
1257 png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
1258
1259 for (i = 0; i < num_hist; i++)
1260 {
1261 png_save_uint_16(buf, hist[i]);
1262 png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1263 }
1264
1265 png_write_chunk_end(png_ptr);
1266 }
1267 #endif
1268
1269 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1270 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1271 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1272 * and if invalid, correct the keyword rather than discarding the entire
1273 * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1274 * length, forbids leading or trailing whitespace, multiple internal spaces,
1275 * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1276 *
1277 * The new_key is allocated to hold the corrected keyword and must be freed
1278 * by the calling routine. This avoids problems with trying to write to
1279 * static keywords without having to have duplicate copies of the strings.
1280 */
1281 png_size_t /* PRIVATE */
1282 png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)
1283 {
1284 png_size_t key_len;
1285 png_const_charp ikp;
1286 png_charp kp, dp;
1287 int kflag;
1288 int kwarn=0;
1289
1290 png_debug(1, "in png_check_keyword");
1291
1292 *new_key = NULL;
1293
1294 if (key == NULL || (key_len = png_strlen(key)) == 0)
1295 {
1296 png_warning(png_ptr, "zero length keyword");
1297 return ((png_size_t)0);
1298 }
1299
1300 png_debug1(2, "Keyword to be checked is '%s'", key);
1301
1302 *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1303
1304 if (*new_key == NULL)
1305 {
1306 png_warning(png_ptr, "Out of memory while procesing keyword");
1307 return ((png_size_t)0);
1308 }
1309
1310 /* Replace non-printing characters with a blank and print a warning */
1311 for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++)
1312 {
1313 if ((png_byte)*ikp < 0x20 ||
1314 ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1))
1315 {
1316 #ifdef PNG_CONSOLE_IO_SUPPORTED
1317 char msg[40];
1318
1319 png_snprintf(msg, 40,
1320 "invalid keyword character 0x%02X", (png_byte)*ikp);
1321 png_warning(png_ptr, msg);
1322 #else
1323 png_warning(png_ptr, "invalid character in keyword");
1324 #endif
1325 *dp = ' ';
1326 }
1327
1328 else
1329 {
1330 *dp = *ikp;
1331 }
1332 }
1333 *dp = '\0';
1334
1335 /* Remove any trailing white space. */
1336 kp = *new_key + key_len - 1;
1337 if (*kp == ' ')
1338 {
1339 png_warning(png_ptr, "trailing spaces removed from keyword");
1340
1341 while (*kp == ' ')
1342 {
1343 *(kp--) = '\0';
1344 key_len--;
1345 }
1346 }
1347
1348 /* Remove any leading white space. */
1349 kp = *new_key;
1350 if (*kp == ' ')
1351 {
1352 png_warning(png_ptr, "leading spaces removed from keyword");
1353
1354 while (*kp == ' ')
1355 {
1356 kp++;
1357 key_len--;
1358 }
1359 }
1360
1361 png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
1362
1363 /* Remove multiple internal spaces. */
1364 for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1365 {
1366 if (*kp == ' ' && kflag == 0)
1367 {
1368 *(dp++) = *kp;
1369 kflag = 1;
1370 }
1371
1372 else if (*kp == ' ')
1373 {
1374 key_len--;
1375 kwarn = 1;
1376 }
1377
1378 else
1379 {
1380 *(dp++) = *kp;
1381 kflag = 0;
1382 }
1383 }
1384 *dp = '\0';
1385 if (kwarn)
1386 png_warning(png_ptr, "extra interior spaces removed from keyword");
1387
1388 if (key_len == 0)
1389 {
1390 png_free(png_ptr, *new_key);
1391 png_warning(png_ptr, "Zero length keyword");
1392 }
1393
1394 if (key_len > 79)
1395 {
1396 png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1397 (*new_key)[79] = '\0';
1398 key_len = 79;
1399 }
1400
1401 return (key_len);
1402 }
1403 #endif
1404
1405 #ifdef PNG_WRITE_tEXt_SUPPORTED
1406 /* Write a tEXt chunk */
1407 void /* PRIVATE */
1408 png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
1409 png_size_t text_len)
1410 {
1411 PNG_tEXt;
1412 png_size_t key_len;
1413 png_charp new_key;
1414
1415 png_debug(1, "in png_write_tEXt");
1416
1417 if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1418 return;
1419
1420 if (text == NULL || *text == '\0')
1421 text_len = 0;
1422
1423 else
1424 text_len = png_strlen(text);
1425
1426 /* Make sure we include the 0 after the key */
1427 png_write_chunk_start(png_ptr, png_tEXt,
1428 (png_uint_32)(key_len + text_len + 1));
1429 /*
1430 * We leave it to the application to meet PNG-1.0 requirements on the
1431 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1432 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1433 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1434 */
1435 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1436 (png_size_t)(key_len + 1));
1437
1438 if (text_len)
1439 png_write_chunk_data(png_ptr, (png_const_bytep)text,
1440 (png_size_t)text_len);
1441
1442 png_write_chunk_end(png_ptr);
1443 png_free(png_ptr, new_key);
1444 }
1445 #endif
1446
1447 #ifdef PNG_WRITE_zTXt_SUPPORTED
1448 /* Write a compressed text chunk */
1449 void /* PRIVATE */
1450 png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
1451 png_size_t text_len, int compression)
1452 {
1453 PNG_zTXt;
1454 png_size_t key_len;
1455 png_byte buf;
1456 png_charp new_key;
1457 compression_state comp;
1458
1459 png_debug(1, "in png_write_zTXt");
1460
1461 comp.num_output_ptr = 0;
1462 comp.max_output_ptr = 0;
1463 comp.output_ptr = NULL;
1464 comp.input = NULL;
1465 comp.input_len = 0;
1466
1467 if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
1468 {
1469 png_free(png_ptr, new_key);
1470 return;
1471 }
1472
1473 if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1474 {
1475 png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1476 png_free(png_ptr, new_key);
1477 return;
1478 }
1479
1480 text_len = png_strlen(text);
1481
1482 /* Compute the compressed data; do it now for the length */
1483 text_len = png_text_compress(png_ptr, text, text_len, compression,
1484 &comp);
1485
1486 /* Write start of chunk */
1487 png_write_chunk_start(png_ptr, png_zTXt,
1488 (png_uint_32)(key_len+text_len + 2));
1489
1490 /* Write key */
1491 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1492 (png_size_t)(key_len + 1));
1493
1494 png_free(png_ptr, new_key);
1495
1496 buf = (png_byte)compression;
1497
1498 /* Write compression */
1499 png_write_chunk_data(png_ptr, &buf, (png_size_t)1);
1500
1501 /* Write the compressed data */
1502 png_write_compressed_data_out(png_ptr, &comp);
1503
1504 /* Close the chunk */
1505 png_write_chunk_end(png_ptr);
1506 }
1507 #endif
1508
1509 #ifdef PNG_WRITE_iTXt_SUPPORTED
1510 /* Write an iTXt chunk */
1511 void /* PRIVATE */
1512 png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key,
1513 png_const_charp lang, png_const_charp lang_key, png_const_charp text)
1514 {
1515 PNG_iTXt;
1516 png_size_t lang_len, key_len, lang_key_len, text_len;
1517 png_charp new_lang;
1518 png_charp new_key = NULL;
1519 png_byte cbuf[2];
1520 compression_state comp;
1521
1522 png_debug(1, "in png_write_iTXt");
1523
1524 comp.num_output_ptr = 0;
1525 comp.max_output_ptr = 0;
1526 comp.output_ptr = NULL;
1527 comp.input = NULL;
1528
1529 if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)
1530 return;
1531
1532 if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0)
1533 {
1534 png_warning(png_ptr, "Empty language field in iTXt chunk");
1535 new_lang = NULL;
1536 lang_len = 0;
1537 }
1538
1539 if (lang_key == NULL)
1540 lang_key_len = 0;
1541
1542 else
1543 lang_key_len = png_strlen(lang_key);
1544
1545 if (text == NULL)
1546 text_len = 0;
1547
1548 else
1549 text_len = png_strlen(text);
1550
1551 /* Compute the compressed data; do it now for the length */
1552 text_len = png_text_compress(png_ptr, text, text_len, compression - 2,
1553 &comp);
1554
1555
1556 /* Make sure we include the compression flag, the compression byte,
1557 * and the NULs after the key, lang, and lang_key parts
1558 */
1559
1560 png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)(
1561 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1562 + key_len
1563 + lang_len
1564 + lang_key_len
1565 + text_len));
1566
1567 /* We leave it to the application to meet PNG-1.0 requirements on the
1568 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1569 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1570 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1571 */
1572 png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1));
1573
1574 /* Set the compression flag */
1575 if (compression == PNG_ITXT_COMPRESSION_NONE ||
1576 compression == PNG_TEXT_COMPRESSION_NONE)
1577 cbuf[0] = 0;
1578
1579 else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1580 cbuf[0] = 1;
1581
1582 /* Set the compression method */
1583 cbuf[1] = 0;
1584
1585 png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
1586
1587 cbuf[0] = 0;
1588 png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf),
1589 (png_size_t)(lang_len + 1));
1590
1591 png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf),
1592 (png_size_t)(lang_key_len + 1));
1593
1594 png_write_compressed_data_out(png_ptr, &comp);
1595
1596 png_write_chunk_end(png_ptr);
1597
1598 png_free(png_ptr, new_key);
1599 png_free(png_ptr, new_lang);
1600 }
1601 #endif
1602
1603 #ifdef PNG_WRITE_oFFs_SUPPORTED
1604 /* Write the oFFs chunk */
1605 void /* PRIVATE */
1606 png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1607 int unit_type)
1608 {
1609 PNG_oFFs;
1610 png_byte buf[9];
1611
1612 png_debug(1, "in png_write_oFFs");
1613
1614 if (unit_type >= PNG_OFFSET_LAST)
1615 png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1616
1617 png_save_int_32(buf, x_offset);
1618 png_save_int_32(buf + 4, y_offset);
1619 buf[8] = (png_byte)unit_type;
1620
1621 png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
1622 }
1623 #endif
1624 #ifdef PNG_WRITE_pCAL_SUPPORTED
1625 /* Write the pCAL chunk (described in the PNG extensions document) */
1626 void /* PRIVATE */
1627 png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1628 png_int_32 X1, int type, int nparams, png_const_charp units,
1629 png_charpp params)
1630 {
1631 PNG_pCAL;
1632 png_size_t purpose_len, units_len, total_len;
1633 png_uint_32p params_len;
1634 png_byte buf[10];
1635 png_charp new_purpose;
1636 int i;
1637
1638 png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
1639
1640 if (type >= PNG_EQUATION_LAST)
1641 png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1642
1643 purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1644 png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
1645 units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1646 png_debug1(3, "pCAL units length = %d", (int)units_len);
1647 total_len = purpose_len + units_len + 10;
1648
1649 params_len = (png_uint_32p)png_malloc(png_ptr,
1650 (png_alloc_size_t)(nparams * png_sizeof(png_uint_32)));
1651
1652 /* Find the length of each parameter, making sure we don't count the
1653 * null terminator for the last parameter.
1654 */
1655 for (i = 0; i < nparams; i++)
1656 {
1657 params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1658 png_debug2(3, "pCAL parameter %d length = %lu", i,
1659 (unsigned long)params_len[i]);
1660 total_len += (png_size_t)params_len[i];
1661 }
1662
1663 png_debug1(3, "pCAL total length = %d", (int)total_len);
1664 png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len);
1665 png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose,
1666 (png_size_t)purpose_len);
1667 png_save_int_32(buf, X0);
1668 png_save_int_32(buf + 4, X1);
1669 buf[8] = (png_byte)type;
1670 buf[9] = (png_byte)nparams;
1671 png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1672 png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
1673
1674 png_free(png_ptr, new_purpose);
1675
1676 for (i = 0; i < nparams; i++)
1677 {
1678 png_write_chunk_data(png_ptr, (png_const_bytep)params[i],
1679 (png_size_t)params_len[i]);
1680 }
1681
1682 png_free(png_ptr, params_len);
1683 png_write_chunk_end(png_ptr);
1684 }
1685 #endif
1686
1687 #ifdef PNG_WRITE_sCAL_SUPPORTED
1688 /* Write the sCAL chunk */
1689 void /* PRIVATE */
1690 png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width,
1691 png_const_charp height)
1692 {
1693 PNG_sCAL;
1694 png_byte buf[64];
1695 png_size_t wlen, hlen, total_len;
1696
1697 png_debug(1, "in png_write_sCAL_s");
1698
1699 wlen = png_strlen(width);
1700 hlen = png_strlen(height);
1701 total_len = wlen + hlen + 2;
1702
1703 if (total_len > 64)
1704 {
1705 png_warning(png_ptr, "Can't write sCAL (buffer too small)");
1706 return;
1707 }
1708
1709 buf[0] = (png_byte)unit;
1710 png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
1711 png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
1712
1713 png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1714 png_write_chunk(png_ptr, png_sCAL, buf, total_len);
1715 }
1716 #endif
1717
1718 #ifdef PNG_WRITE_pHYs_SUPPORTED
1719 /* Write the pHYs chunk */
1720 void /* PRIVATE */
1721 png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1722 png_uint_32 y_pixels_per_unit,
1723 int unit_type)
1724 {
1725 PNG_pHYs;
1726 png_byte buf[9];
1727
1728 png_debug(1, "in png_write_pHYs");
1729
1730 if (unit_type >= PNG_RESOLUTION_LAST)
1731 png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1732
1733 png_save_uint_32(buf, x_pixels_per_unit);
1734 png_save_uint_32(buf + 4, y_pixels_per_unit);
1735 buf[8] = (png_byte)unit_type;
1736
1737 png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
1738 }
1739 #endif
1740
1741 #ifdef PNG_WRITE_tIME_SUPPORTED
1742 /* Write the tIME chunk. Use either png_convert_from_struct_tm()
1743 * or png_convert_from_time_t(), or fill in the structure yourself.
1744 */
1745 void /* PRIVATE */
1746 png_write_tIME(png_structp png_ptr, png_const_timep mod_time)
1747 {
1748 PNG_tIME;
1749 png_byte buf[7];
1750
1751 png_debug(1, "in png_write_tIME");
1752
1753 if (mod_time->month > 12 || mod_time->month < 1 ||
1754 mod_time->day > 31 || mod_time->day < 1 ||
1755 mod_time->hour > 23 || mod_time->second > 60)
1756 {
1757 png_warning(png_ptr, "Invalid time specified for tIME chunk");
1758 return;
1759 }
1760
1761 png_save_uint_16(buf, mod_time->year);
1762 buf[2] = mod_time->month;
1763 buf[3] = mod_time->day;
1764 buf[4] = mod_time->hour;
1765 buf[5] = mod_time->minute;
1766 buf[6] = mod_time->second;
1767
1768 png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
1769 }
1770 #endif
1771
1772 /* Initializes the row writing capability of libpng */
1773 void /* PRIVATE */
1774 png_write_start_row(png_structp png_ptr)
1775 {
1776 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1777 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1778
1779 /* Start of interlace block */
1780 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1781
1782 /* Offset to next interlace block */
1783 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1784
1785 /* Start of interlace block in the y direction */
1786 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1787
1788 /* Offset to next interlace block in the y direction */
1789 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1790 #endif
1791
1792 png_size_t buf_size;
1793
1794 png_debug(1, "in png_write_start_row");
1795
1796 buf_size = (png_size_t)(PNG_ROWBYTES(
1797 png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
1798
1799 /* Set up row buffer */
1800 png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
1801 (png_alloc_size_t)buf_size);
1802
1803 png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1804
1805 #ifdef PNG_WRITE_FILTER_SUPPORTED
1806 /* Set up filtering buffer, if using this filter */
1807 if (png_ptr->do_filter & PNG_FILTER_SUB)
1808 {
1809 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
1810
1811 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1812 }
1813
1814 /* We only need to keep the previous row if we are using one of these. */
1815 if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1816 {
1817 /* Set up previous row buffer */
1818 png_ptr->prev_row = (png_bytep)png_calloc(png_ptr,
1819 (png_alloc_size_t)buf_size);
1820
1821 if (png_ptr->do_filter & PNG_FILTER_UP)
1822 {
1823 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1824 png_ptr->rowbytes + 1);
1825
1826 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1827 }
1828
1829 if (png_ptr->do_filter & PNG_FILTER_AVG)
1830 {
1831 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1832 png_ptr->rowbytes + 1);
1833
1834 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1835 }
1836
1837 if (png_ptr->do_filter & PNG_FILTER_PAETH)
1838 {
1839 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1840 png_ptr->rowbytes + 1);
1841
1842 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1843 }
1844 }
1845 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1846
1847 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1848 /* If interlaced, we need to set up width and height of pass */
1849 if (png_ptr->interlaced)
1850 {
1851 if (!(png_ptr->transformations & PNG_INTERLACE))
1852 {
1853 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1854 png_pass_ystart[0]) / png_pass_yinc[0];
1855
1856 png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1857 png_pass_start[0]) / png_pass_inc[0];
1858 }
1859
1860 else
1861 {
1862 png_ptr->num_rows = png_ptr->height;
1863 png_ptr->usr_width = png_ptr->width;
1864 }
1865 }
1866
1867 else
1868 #endif
1869 {
1870 png_ptr->num_rows = png_ptr->height;
1871 png_ptr->usr_width = png_ptr->width;
1872 }
1873
1874 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1875 png_ptr->zstream.next_out = png_ptr->zbuf;
1876 }
1877
1878 /* Internal use only. Called when finished processing a row of data. */
1879 void /* PRIVATE */
1880 png_write_finish_row(png_structp png_ptr)
1881 {
1882 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1883 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1884
1885 /* Start of interlace block */
1886 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1887
1888 /* Offset to next interlace block */
1889 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1890
1891 /* Start of interlace block in the y direction */
1892 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1893
1894 /* Offset to next interlace block in the y direction */
1895 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1896 #endif
1897
1898 int ret;
1899
1900 png_debug(1, "in png_write_finish_row");
1901
1902 /* Next row */
1903 png_ptr->row_number++;
1904
1905 /* See if we are done */
1906 if (png_ptr->row_number < png_ptr->num_rows)
1907 return;
1908
1909 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1910 /* If interlaced, go to next pass */
1911 if (png_ptr->interlaced)
1912 {
1913 png_ptr->row_number = 0;
1914 if (png_ptr->transformations & PNG_INTERLACE)
1915 {
1916 png_ptr->pass++;
1917 }
1918
1919 else
1920 {
1921 /* Loop until we find a non-zero width or height pass */
1922 do
1923 {
1924 png_ptr->pass++;
1925
1926 if (png_ptr->pass >= 7)
1927 break;
1928
1929 png_ptr->usr_width = (png_ptr->width +
1930 png_pass_inc[png_ptr->pass] - 1 -
1931 png_pass_start[png_ptr->pass]) /
1932 png_pass_inc[png_ptr->pass];
1933
1934 png_ptr->num_rows = (png_ptr->height +
1935 png_pass_yinc[png_ptr->pass] - 1 -
1936 png_pass_ystart[png_ptr->pass]) /
1937 png_pass_yinc[png_ptr->pass];
1938
1939 if (png_ptr->transformations & PNG_INTERLACE)
1940 break;
1941
1942 } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1943
1944 }
1945
1946 /* Reset the row above the image for the next pass */
1947 if (png_ptr->pass < 7)
1948 {
1949 if (png_ptr->prev_row != NULL)
1950 png_memset(png_ptr->prev_row, 0,
1951 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
1952 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
1953
1954 return;
1955 }
1956 }
1957 #endif
1958
1959 /* If we get here, we've just written the last row, so we need
1960 to flush the compressor */
1961 do
1962 {
1963 /* Tell the compressor we are done */
1964 ret = deflate(&png_ptr->zstream, Z_FINISH);
1965
1966 /* Check for an error */
1967 if (ret == Z_OK)
1968 {
1969 /* Check to see if we need more room */
1970 if (!(png_ptr->zstream.avail_out))
1971 {
1972 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1973 png_ptr->zstream.next_out = png_ptr->zbuf;
1974 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1975 }
1976 }
1977
1978 else if (ret != Z_STREAM_END)
1979 {
1980 if (png_ptr->zstream.msg != NULL)
1981 png_error(png_ptr, png_ptr->zstream.msg);
1982
1983 else
1984 png_error(png_ptr, "zlib error");
1985 }
1986 } while (ret != Z_STREAM_END);
1987
1988 /* Write any extra space */
1989 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1990 {
1991 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1992 png_ptr->zstream.avail_out);
1993 }
1994
1995 deflateReset(&png_ptr->zstream);
1996 png_ptr->zstream.data_type = Z_BINARY;
1997 }
1998
1999 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
2000 /* Pick out the correct pixels for the interlace pass.
2001 * The basic idea here is to go through the row with a source
2002 * pointer and a destination pointer (sp and dp), and copy the
2003 * correct pixels for the pass. As the row gets compacted,
2004 * sp will always be >= dp, so we should never overwrite anything.
2005 * See the default: case for the easiest code to understand.
2006 */
2007 void /* PRIVATE */
2008 png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
2009 {
2010 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
2011
2012 /* Start of interlace block */
2013 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
2014
2015 /* Offset to next interlace block */
2016 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
2017
2018 png_debug(1, "in png_do_write_interlace");
2019
2020 /* We don't have to do anything on the last pass (6) */
2021 if (pass < 6)
2022 {
2023 /* Each pixel depth is handled separately */
2024 switch (row_info->pixel_depth)
2025 {
2026 case 1:
2027 {
2028 png_bytep sp;
2029 png_bytep dp;
2030 int shift;
2031 int d;
2032 int value;
2033 png_uint_32 i;
2034 png_uint_32 row_width = row_info->width;
2035
2036 dp = row;
2037 d = 0;
2038 shift = 7;
2039
2040 for (i = png_pass_start[pass]; i < row_width;
2041 i += png_pass_inc[pass])
2042 {
2043 sp = row + (png_size_t)(i >> 3);
2044 value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
2045 d |= (value << shift);
2046
2047 if (shift == 0)
2048 {
2049 shift = 7;
2050 *dp++ = (png_byte)d;
2051 d = 0;
2052 }
2053
2054 else
2055 shift--;
2056
2057 }
2058 if (shift != 7)
2059 *dp = (png_byte)d;
2060
2061 break;
2062 }
2063
2064 case 2:
2065 {
2066 png_bytep sp;
2067 png_bytep dp;
2068 int shift;
2069 int d;
2070 int value;
2071 png_uint_32 i;
2072 png_uint_32 row_width = row_info->width;
2073
2074 dp = row;
2075 shift = 6;
2076 d = 0;
2077
2078 for (i = png_pass_start[pass]; i < row_width;
2079 i += png_pass_inc[pass])
2080 {
2081 sp = row + (png_size_t)(i >> 2);
2082 value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
2083 d |= (value << shift);
2084
2085 if (shift == 0)
2086 {
2087 shift = 6;
2088 *dp++ = (png_byte)d;
2089 d = 0;
2090 }
2091
2092 else
2093 shift -= 2;
2094 }
2095 if (shift != 6)
2096 *dp = (png_byte)d;
2097
2098 break;
2099 }
2100
2101 case 4:
2102 {
2103 png_bytep sp;
2104 png_bytep dp;
2105 int shift;
2106 int d;
2107 int value;
2108 png_uint_32 i;
2109 png_uint_32 row_width = row_info->width;
2110
2111 dp = row;
2112 shift = 4;
2113 d = 0;
2114 for (i = png_pass_start[pass]; i < row_width;
2115 i += png_pass_inc[pass])
2116 {
2117 sp = row + (png_size_t)(i >> 1);
2118 value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
2119 d |= (value << shift);
2120
2121 if (shift == 0)
2122 {
2123 shift = 4;
2124 *dp++ = (png_byte)d;
2125 d = 0;
2126 }
2127
2128 else
2129 shift -= 4;
2130 }
2131 if (shift != 4)
2132 *dp = (png_byte)d;
2133
2134 break;
2135 }
2136
2137 default:
2138 {
2139 png_bytep sp;
2140 png_bytep dp;
2141 png_uint_32 i;
2142 png_uint_32 row_width = row_info->width;
2143 png_size_t pixel_bytes;
2144
2145 /* Start at the beginning */
2146 dp = row;
2147
2148 /* Find out how many bytes each pixel takes up */
2149 pixel_bytes = (row_info->pixel_depth >> 3);
2150
2151 /* Loop through the row, only looking at the pixels that matter */
2152 for (i = png_pass_start[pass]; i < row_width;
2153 i += png_pass_inc[pass])
2154 {
2155 /* Find out where the original pixel is */
2156 sp = row + (png_size_t)i * pixel_bytes;
2157
2158 /* Move the pixel */
2159 if (dp != sp)
2160 png_memcpy(dp, sp, pixel_bytes);
2161
2162 /* Next pixel */
2163 dp += pixel_bytes;
2164 }
2165 break;
2166 }
2167 }
2168 /* Set new row width */
2169 row_info->width = (row_info->width +
2170 png_pass_inc[pass] - 1 -
2171 png_pass_start[pass]) /
2172 png_pass_inc[pass];
2173
2174 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2175 row_info->width);
2176 }
2177 }
2178 #endif
2179
2180 /* This filters the row, chooses which filter to use, if it has not already
2181 * been specified by the application, and then writes the row out with the
2182 * chosen filter.
2183 */
2184 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
2185 #define PNG_HISHIFT 10
2186 #define PNG_LOMASK ((png_uint_32)0xffffL)
2187 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2188 void /* PRIVATE */
2189 png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2190 {
2191 png_bytep best_row;
2192 #ifdef PNG_WRITE_FILTER_SUPPORTED
2193 png_bytep prev_row, row_buf;
2194 png_uint_32 mins, bpp;
2195 png_byte filter_to_do = png_ptr->do_filter;
2196 png_size_t row_bytes = row_info->rowbytes;
2197 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2198 int num_p_filters = (int)png_ptr->num_prev_filters;
2199 #endif
2200
2201 png_debug(1, "in png_write_find_filter");
2202
2203 #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2204 if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
2205 {
2206 /* These will never be selected so we need not test them. */
2207 filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
2208 }
2209 #endif
2210
2211 /* Find out how many bytes offset each pixel is */
2212 bpp = (row_info->pixel_depth + 7) >> 3;
2213
2214 prev_row = png_ptr->prev_row;
2215 #endif
2216 best_row = png_ptr->row_buf;
2217 #ifdef PNG_WRITE_FILTER_SUPPORTED
2218 row_buf = best_row;
2219 mins = PNG_MAXSUM;
2220
2221 /* The prediction method we use is to find which method provides the
2222 * smallest value when summing the absolute values of the distances
2223 * from zero, using anything >= 128 as negative numbers. This is known
2224 * as the "minimum sum of absolute differences" heuristic. Other
2225 * heuristics are the "weighted minimum sum of absolute differences"
2226 * (experimental and can in theory improve compression), and the "zlib
2227 * predictive" method (not implemented yet), which does test compressions
2228 * of lines using different filter methods, and then chooses the
2229 * (series of) filter(s) that give minimum compressed data size (VERY
2230 * computationally expensive).
2231 *
2232 * GRR 980525: consider also
2233 *
2234 * (1) minimum sum of absolute differences from running average (i.e.,
2235 * keep running sum of non-absolute differences & count of bytes)
2236 * [track dispersion, too? restart average if dispersion too large?]
2237 *
2238 * (1b) minimum sum of absolute differences from sliding average, probably
2239 * with window size <= deflate window (usually 32K)
2240 *
2241 * (2) minimum sum of squared differences from zero or running average
2242 * (i.e., ~ root-mean-square approach)
2243 */
2244
2245
2246 /* We don't need to test the 'no filter' case if this is the only filter
2247 * that has been chosen, as it doesn't actually do anything to the data.
2248 */
2249 if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)
2250 {
2251 png_bytep rp;
2252 png_uint_32 sum = 0;
2253 png_size_t i;
2254 int v;
2255
2256 for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2257 {
2258 v = *rp;
2259 sum += (v < 128) ? v : 256 - v;
2260 }
2261
2262 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2263 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2264 {
2265 png_uint_32 sumhi, sumlo;
2266 int j;
2267 sumlo = sum & PNG_LOMASK;
2268 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2269
2270 /* Reduce the sum if we match any of the previous rows */
2271 for (j = 0; j < num_p_filters; j++)
2272 {
2273 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2274 {
2275 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2276 PNG_WEIGHT_SHIFT;
2277
2278 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2279 PNG_WEIGHT_SHIFT;
2280 }
2281 }
2282
2283 /* Factor in the cost of this filter (this is here for completeness,
2284 * but it makes no sense to have a "cost" for the NONE filter, as
2285 * it has the minimum possible computational cost - none).
2286 */
2287 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2288 PNG_COST_SHIFT;
2289
2290 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2291 PNG_COST_SHIFT;
2292
2293 if (sumhi > PNG_HIMASK)
2294 sum = PNG_MAXSUM;
2295
2296 else
2297 sum = (sumhi << PNG_HISHIFT) + sumlo;
2298 }
2299 #endif
2300 mins = sum;
2301 }
2302
2303 /* Sub filter */
2304 if (filter_to_do == PNG_FILTER_SUB)
2305 /* It's the only filter so no testing is needed */
2306 {
2307 png_bytep rp, lp, dp;
2308 png_size_t i;
2309
2310 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2311 i++, rp++, dp++)
2312 {
2313 *dp = *rp;
2314 }
2315
2316 for (lp = row_buf + 1; i < row_bytes;
2317 i++, rp++, lp++, dp++)
2318 {
2319 *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2320 }
2321
2322 best_row = png_ptr->sub_row;
2323 }
2324
2325 else if (filter_to_do & PNG_FILTER_SUB)
2326 {
2327 png_bytep rp, dp, lp;
2328 png_uint_32 sum = 0, lmins = mins;
2329 png_size_t i;
2330 int v;
2331
2332 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2333 /* We temporarily increase the "minimum sum" by the factor we
2334 * would reduce the sum of this filter, so that we can do the
2335 * early exit comparison without scaling the sum each time.
2336 */
2337 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2338 {
2339 int j;
2340 png_uint_32 lmhi, lmlo;
2341 lmlo = lmins & PNG_LOMASK;
2342 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2343
2344 for (j = 0; j < num_p_filters; j++)
2345 {
2346 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2347 {
2348 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2349 PNG_WEIGHT_SHIFT;
2350
2351 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2352 PNG_WEIGHT_SHIFT;
2353 }
2354 }
2355
2356 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2357 PNG_COST_SHIFT;
2358
2359 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2360 PNG_COST_SHIFT;
2361
2362 if (lmhi > PNG_HIMASK)
2363 lmins = PNG_MAXSUM;
2364
2365 else
2366 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2367 }
2368 #endif
2369
2370 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2371 i++, rp++, dp++)
2372 {
2373 v = *dp = *rp;
2374
2375 sum += (v < 128) ? v : 256 - v;
2376 }
2377
2378 for (lp = row_buf + 1; i < row_bytes;
2379 i++, rp++, lp++, dp++)
2380 {
2381 v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2382
2383 sum += (v < 128) ? v : 256 - v;
2384
2385 if (sum > lmins) /* We are already worse, don't continue. */
2386 break;
2387 }
2388
2389 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2390 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2391 {
2392 int j;
2393 png_uint_32 sumhi, sumlo;
2394 sumlo = sum & PNG_LOMASK;
2395 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2396
2397 for (j = 0; j < num_p_filters; j++)
2398 {
2399 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2400 {
2401 sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2402 PNG_WEIGHT_SHIFT;
2403
2404 sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2405 PNG_WEIGHT_SHIFT;
2406 }
2407 }
2408
2409 sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2410 PNG_COST_SHIFT;
2411
2412 sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2413 PNG_COST_SHIFT;
2414
2415 if (sumhi > PNG_HIMASK)
2416 sum = PNG_MAXSUM;
2417
2418 else
2419 sum = (sumhi << PNG_HISHIFT) + sumlo;
2420 }
2421 #endif
2422
2423 if (sum < mins)
2424 {
2425 mins = sum;
2426 best_row = png_ptr->sub_row;
2427 }
2428 }
2429
2430 /* Up filter */
2431 if (filter_to_do == PNG_FILTER_UP)
2432 {
2433 png_bytep rp, dp, pp;
2434 png_size_t i;
2435
2436 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2437 pp = prev_row + 1; i < row_bytes;
2438 i++, rp++, pp++, dp++)
2439 {
2440 *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2441 }
2442
2443 best_row = png_ptr->up_row;
2444 }
2445
2446 else if (filter_to_do & PNG_FILTER_UP)
2447 {
2448 png_bytep rp, dp, pp;
2449 png_uint_32 sum = 0, lmins = mins;
2450 png_size_t i;
2451 int v;
2452
2453
2454 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2455 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2456 {
2457 int j;
2458 png_uint_32 lmhi, lmlo;
2459 lmlo = lmins & PNG_LOMASK;
2460 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2461
2462 for (j = 0; j < num_p_filters; j++)
2463 {
2464 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2465 {
2466 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2467 PNG_WEIGHT_SHIFT;
2468
2469 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2470 PNG_WEIGHT_SHIFT;
2471 }
2472 }
2473
2474 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2475 PNG_COST_SHIFT;
2476
2477 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2478 PNG_COST_SHIFT;
2479
2480 if (lmhi > PNG_HIMASK)
2481 lmins = PNG_MAXSUM;
2482
2483 else
2484 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2485 }
2486 #endif
2487
2488 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2489 pp = prev_row + 1; i < row_bytes; i++)
2490 {
2491 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2492
2493 sum += (v < 128) ? v : 256 - v;
2494
2495 if (sum > lmins) /* We are already worse, don't continue. */
2496 break;
2497 }
2498
2499 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2500 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2501 {
2502 int j;
2503 png_uint_32 sumhi, sumlo;
2504 sumlo = sum & PNG_LOMASK;
2505 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2506
2507 for (j = 0; j < num_p_filters; j++)
2508 {
2509 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2510 {
2511 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2512 PNG_WEIGHT_SHIFT;
2513
2514 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2515 PNG_WEIGHT_SHIFT;
2516 }
2517 }
2518
2519 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2520 PNG_COST_SHIFT;
2521
2522 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2523 PNG_COST_SHIFT;
2524
2525 if (sumhi > PNG_HIMASK)
2526 sum = PNG_MAXSUM;
2527
2528 else
2529 sum = (sumhi << PNG_HISHIFT) + sumlo;
2530 }
2531 #endif
2532
2533 if (sum < mins)
2534 {
2535 mins = sum;
2536 best_row = png_ptr->up_row;
2537 }
2538 }
2539
2540 /* Avg filter */
2541 if (filter_to_do == PNG_FILTER_AVG)
2542 {
2543 png_bytep rp, dp, pp, lp;
2544 png_uint_32 i;
2545
2546 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2547 pp = prev_row + 1; i < bpp; i++)
2548 {
2549 *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2550 }
2551
2552 for (lp = row_buf + 1; i < row_bytes; i++)
2553 {
2554 *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2555 & 0xff);
2556 }
2557 best_row = png_ptr->avg_row;
2558 }
2559
2560 else if (filter_to_do & PNG_FILTER_AVG)
2561 {
2562 png_bytep rp, dp, pp, lp;
2563 png_uint_32 sum = 0, lmins = mins;
2564 png_size_t i;
2565 int v;
2566
2567 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2568 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2569 {
2570 int j;
2571 png_uint_32 lmhi, lmlo;
2572 lmlo = lmins & PNG_LOMASK;
2573 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2574
2575 for (j = 0; j < num_p_filters; j++)
2576 {
2577 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2578 {
2579 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2580 PNG_WEIGHT_SHIFT;
2581
2582 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2583 PNG_WEIGHT_SHIFT;
2584 }
2585 }
2586
2587 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2588 PNG_COST_SHIFT;
2589
2590 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2591 PNG_COST_SHIFT;
2592
2593 if (lmhi > PNG_HIMASK)
2594 lmins = PNG_MAXSUM;
2595
2596 else
2597 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2598 }
2599 #endif
2600
2601 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2602 pp = prev_row + 1; i < bpp; i++)
2603 {
2604 v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2605
2606 sum += (v < 128) ? v : 256 - v;
2607 }
2608
2609 for (lp = row_buf + 1; i < row_bytes; i++)
2610 {
2611 v = *dp++ =
2612 (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2613
2614 sum += (v < 128) ? v : 256 - v;
2615
2616 if (sum > lmins) /* We are already worse, don't continue. */
2617 break;
2618 }
2619
2620 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2621 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2622 {
2623 int j;
2624 png_uint_32 sumhi, sumlo;
2625 sumlo = sum & PNG_LOMASK;
2626 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2627
2628 for (j = 0; j < num_p_filters; j++)
2629 {
2630 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2631 {
2632 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2633 PNG_WEIGHT_SHIFT;
2634
2635 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2636 PNG_WEIGHT_SHIFT;
2637 }
2638 }
2639
2640 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2641 PNG_COST_SHIFT;
2642
2643 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2644 PNG_COST_SHIFT;
2645
2646 if (sumhi > PNG_HIMASK)
2647 sum = PNG_MAXSUM;
2648
2649 else
2650 sum = (sumhi << PNG_HISHIFT) + sumlo;
2651 }
2652 #endif
2653
2654 if (sum < mins)
2655 {
2656 mins = sum;
2657 best_row = png_ptr->avg_row;
2658 }
2659 }
2660
2661 /* Paeth filter */
2662 if (filter_to_do == PNG_FILTER_PAETH)
2663 {
2664 png_bytep rp, dp, pp, cp, lp;
2665 png_size_t i;
2666
2667 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2668 pp = prev_row + 1; i < bpp; i++)
2669 {
2670 *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2671 }
2672
2673 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2674 {
2675 int a, b, c, pa, pb, pc, p;
2676
2677 b = *pp++;
2678 c = *cp++;
2679 a = *lp++;
2680
2681 p = b - c;
2682 pc = a - c;
2683
2684 #ifdef PNG_USE_ABS
2685 pa = abs(p);
2686 pb = abs(pc);
2687 pc = abs(p + pc);
2688 #else
2689 pa = p < 0 ? -p : p;
2690 pb = pc < 0 ? -pc : pc;
2691 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2692 #endif
2693
2694 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2695
2696 *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2697 }
2698 best_row = png_ptr->paeth_row;
2699 }
2700
2701 else if (filter_to_do & PNG_FILTER_PAETH)
2702 {
2703 png_bytep rp, dp, pp, cp, lp;
2704 png_uint_32 sum = 0, lmins = mins;
2705 png_size_t i;
2706 int v;
2707
2708 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2709 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2710 {
2711 int j;
2712 png_uint_32 lmhi, lmlo;
2713 lmlo = lmins & PNG_LOMASK;
2714 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2715
2716 for (j = 0; j < num_p_filters; j++)
2717 {
2718 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2719 {
2720 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2721 PNG_WEIGHT_SHIFT;
2722
2723 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2724 PNG_WEIGHT_SHIFT;
2725 }
2726 }
2727
2728 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2729 PNG_COST_SHIFT;
2730
2731 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2732 PNG_COST_SHIFT;
2733
2734 if (lmhi > PNG_HIMASK)
2735 lmins = PNG_MAXSUM;
2736
2737 else
2738 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2739 }
2740 #endif
2741
2742 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2743 pp = prev_row + 1; i < bpp; i++)
2744 {
2745 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2746
2747 sum += (v < 128) ? v : 256 - v;
2748 }
2749
2750 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2751 {
2752 int a, b, c, pa, pb, pc, p;
2753
2754 b = *pp++;
2755 c = *cp++;
2756 a = *lp++;
2757
2758 #ifndef PNG_SLOW_PAETH
2759 p = b - c;
2760 pc = a - c;
2761 #ifdef PNG_USE_ABS
2762 pa = abs(p);
2763 pb = abs(pc);
2764 pc = abs(p + pc);
2765 #else
2766 pa = p < 0 ? -p : p;
2767 pb = pc < 0 ? -pc : pc;
2768 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2769 #endif
2770 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2771 #else /* PNG_SLOW_PAETH */
2772 p = a + b - c;
2773 pa = abs(p - a);
2774 pb = abs(p - b);
2775 pc = abs(p - c);
2776
2777 if (pa <= pb && pa <= pc)
2778 p = a;
2779
2780 else if (pb <= pc)
2781 p = b;
2782
2783 else
2784 p = c;
2785 #endif /* PNG_SLOW_PAETH */
2786
2787 v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2788
2789 sum += (v < 128) ? v : 256 - v;
2790
2791 if (sum > lmins) /* We are already worse, don't continue. */
2792 break;
2793 }
2794
2795 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2796 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2797 {
2798 int j;
2799 png_uint_32 sumhi, sumlo;
2800 sumlo = sum & PNG_LOMASK;
2801 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2802
2803 for (j = 0; j < num_p_filters; j++)
2804 {
2805 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2806 {
2807 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2808 PNG_WEIGHT_SHIFT;
2809
2810 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2811 PNG_WEIGHT_SHIFT;
2812 }
2813 }
2814
2815 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2816 PNG_COST_SHIFT;
2817
2818 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2819 PNG_COST_SHIFT;
2820
2821 if (sumhi > PNG_HIMASK)
2822 sum = PNG_MAXSUM;
2823
2824 else
2825 sum = (sumhi << PNG_HISHIFT) + sumlo;
2826 }
2827 #endif
2828
2829 if (sum < mins)
2830 {
2831 best_row = png_ptr->paeth_row;
2832 }
2833 }
2834 #endif /* PNG_WRITE_FILTER_SUPPORTED */
2835 /* Do the actual writing of the filtered row data from the chosen filter. */
2836
2837 png_write_filtered_row(png_ptr, best_row);
2838
2839 #ifdef PNG_WRITE_FILTER_SUPPORTED
2840 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2841 /* Save the type of filter we picked this time for future calculations */
2842 if (png_ptr->num_prev_filters > 0)
2843 {
2844 int j;
2845
2846 for (j = 1; j < num_p_filters; j++)
2847 {
2848 png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
2849 }
2850
2851 png_ptr->prev_filters[j] = best_row[0];
2852 }
2853 #endif
2854 #endif /* PNG_WRITE_FILTER_SUPPORTED */
2855 }
2856
2857
2858 /* Do the actual writing of a previously filtered row. */
2859 void /* PRIVATE */
2860 png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2861 {
2862 png_size_t avail;
2863
2864 png_debug(1, "in png_write_filtered_row");
2865
2866 png_debug1(2, "filter = %d", filtered_row[0]);
2867 /* Set up the zlib input buffer */
2868
2869 png_ptr->zstream.next_in = filtered_row;
2870 png_ptr->zstream.avail_in = 0;
2871 avail = png_ptr->row_info.rowbytes + 1;
2872 /* Repeat until we have compressed all the data */
2873 do
2874 {
2875 int ret; /* Return of zlib */
2876
2877 /* Record the number of bytes available - zlib supports at least 65535
2878 * bytes at one step, depending on the size of the zlib type 'uInt', the
2879 * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h).
2880 * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e.
2881 * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a
2882 * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called
2883 * with smaller chunks of data.
2884 */
2885 if (png_ptr->zstream.avail_in == 0)
2886 {
2887 if (avail > ZLIB_IO_MAX)
2888 {
2889 png_ptr->zstream.avail_in = ZLIB_IO_MAX;
2890 avail -= ZLIB_IO_MAX;
2891 }
2892
2893 else
2894 {
2895 /* So this will fit in the available uInt space: */
2896 png_ptr->zstream.avail_in = (uInt)avail;
2897 avail = 0;
2898 }
2899 }
2900
2901 /* Compress the data */
2902 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2903
2904 /* Check for compression errors */
2905 if (ret != Z_OK)
2906 {
2907 if (png_ptr->zstream.msg != NULL)
2908 png_error(png_ptr, png_ptr->zstream.msg);
2909
2910 else
2911 png_error(png_ptr, "zlib error");
2912 }
2913
2914 /* See if it is time to write another IDAT */
2915 if (!(png_ptr->zstream.avail_out))
2916 {
2917 /* Write the IDAT and reset the zlib output buffer */
2918 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2919 png_ptr->zstream.next_out = png_ptr->zbuf;
2920 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2921 }
2922 /* Repeat until all data has been compressed */
2923 } while (avail > 0 || png_ptr->zstream.avail_in > 0);
2924
2925 /* Swap the current and previous rows */
2926 if (png_ptr->prev_row != NULL)
2927 {
2928 png_bytep tptr;
2929
2930 tptr = png_ptr->prev_row;
2931 png_ptr->prev_row = png_ptr->row_buf;
2932 png_ptr->row_buf = tptr;
2933 }
2934
2935 /* Finish row - updates counters and flushes zlib if last row */
2936 png_write_finish_row(png_ptr);
2937
2938 #ifdef PNG_WRITE_FLUSH_SUPPORTED
2939 png_ptr->flush_rows++;
2940
2941 if (png_ptr->flush_dist > 0 &&
2942 png_ptr->flush_rows >= png_ptr->flush_dist)
2943 {
2944 png_write_flush(png_ptr);
2945 }
2946 #endif
2947 }
2948 #endif /* PNG_WRITE_SUPPORTED */
PNG_PLTE
#define PNG_PLTE
Definition: pngpriv.h:441
PNG_FILTER_VALUE_AVG
#define PNG_FILTER_VALUE_AVG
Definition: png.h:1320
PNG_WEIGHT_SHIFT
#define PNG_WEIGHT_SHIFT
Definition: pnglibconf.h:22
PNG_TEXT_COMPRESSION_LAST
#define PNG_TEXT_COMPRESSION_LAST
Definition: png.h:623
png_write_start_row
void png_write_start_row(png_structp png_ptr)
Definition: pngwutil.c:1774
png_zfree
void png_zfree(voidpf png_ptr, voidpf ptr)
Definition: png.c:99
png_memcpy
#define png_memcpy
Definition: pngpriv.h:226
compression_state
Definition: pngwutil.c:202
voidpf
Byte FAR * voidpf
Definition: zconf.h:355
png_write_sPLT
void png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette)
Definition: pngwutil.c:931
deflateInit2
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy)
Definition: zlib.h:1550
png_write_PLTE
void png_write_PLTE(png_structp png_ptr, png_const_colorp palette, png_uint_32 num_pal)
Definition: pngwutil.c:671
PNG_FILTER_PAETH
#define PNG_FILTER_PAETH
Definition: png.h:1310
png_const_timep
PNG_CONST png_time FAR * png_const_timep
Definition: png.h:641
PNG_cHRM
#define PNG_cHRM
Definition: pngpriv.h:443
PNG_FILTER_HEURISTIC_WEIGHTED
#define PNG_FILTER_HEURISTIC_WEIGHTED
Definition: png.h:1367
png_write_sBIT
void png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type)
Definition: pngwutil.c:1016
PNG_FILTER_SUB
#define PNG_FILTER_SUB
Definition: png.h:1307
Z_NO_FLUSH
#define Z_NO_FLUSH
Definition: zlib.h:164
png_save_int_32
void PNGAPI png_save_int_32(png_bytep buf, png_int_32 i)
Definition: pngwutil.c:40
PNG_INTERLACE_NONE
#define PNG_INTERLACE_NONE
Definition: png.h:708
PNG_COLOR_TYPE_RGB
#define PNG_COLOR_TYPE_RGB
Definition: png.h:691
compression_state::input
png_const_bytep input
Definition: pngwutil.c:204
PNG_COLOR_TYPE_GRAY_ALPHA
#define PNG_COLOR_TYPE_GRAY_ALPHA
Definition: png.h:693
PNG_bKGD
#define PNG_bKGD
Definition: pngpriv.h:442
png_write_gAMA_fixed
void png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
Definition: pngwutil.c:813
PNG_INTERLACE_ADAM7
#define PNG_INTERLACE_ADAM7
Definition: png.h:709
png_charp
char FAR * png_charp
Definition: pngconf.h:572
PNG_COLOR_TYPE_PALETTE
#define PNG_COLOR_TYPE_PALETTE
Definition: png.h:690
compression_state::num_output_ptr
int num_output_ptr
Definition: pngwutil.c:206
PNG_FILTER_VALUE_PAETH
#define PNG_FILTER_VALUE_PAETH
Definition: png.h:1321
PNG_IO_CHUNK_DATA
#define PNG_IO_CHUNK_DATA
Definition: png.h:2109
png_write_zTXt
void png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len, int compression)
Definition: pngwutil.c:1450
PNG_sCAL
#define PNG_sCAL
Definition: pngpriv.h:450
png_debug
#define png_debug(l, m)
Definition: pngdebug.h:149
PNG_COLOR_TYPE_RGB_ALPHA
#define PNG_COLOR_TYPE_RGB_ALPHA
Definition: png.h:692
png_const_colorp
PNG_CONST png_color FAR * png_const_colorp
Definition: png.h:525
png_snprintf
#define png_snprintf
Definition: pngpriv.h:239
png_int_32
long png_int_32
Definition: pngconf.h:481
png_memset
#define png_memset
Definition: pngpriv.h:227
png_const_charp
PNG_CONST char FAR * png_const_charp
Definition: pngconf.h:573
PNG_HIMASK
#define PNG_HIMASK
Definition: pngwutil.c:2187
Z_FILTERED
#define Z_FILTERED
Definition: zlib.h:192
PNG_OFFSET_LAST
#define PNG_OFFSET_LAST
Definition: png.h:715
png_write_oFFs
void png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, int unit_type)
Definition: pngwutil.c:1606
png_write_IDAT
void png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
Definition: pngwutil.c:742
Z_STREAM_ERROR
#define Z_STREAM_ERROR
Definition: zlib.h:177
PNG_tEXt
#define PNG_tEXt
Definition: pngpriv.h:456
png_const_color_8p
PNG_CONST png_color_8 FAR * png_const_color_8p
Definition: png.h:549
PNG_IEND
#define PNG_IEND
Definition: pngpriv.h:440
Bytef
Byte FAR Bytef
Definition: zconf.h:342
b
long b
Definition: jpegint.h:371
PNG_sRGB_INTENT_LAST
#define PNG_sRGB_INTENT_LAST
Definition: png.h:740
PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL
#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL
Definition: pngpriv.h:324
PNG_iCCP
#define PNG_iCCP
Definition: pngpriv.h:446
png_write_pCAL
void png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params)
Definition: pngwutil.c:1627
png_alloc_size_t
png_size_t png_alloc_size_t
Definition: pngconf.h:627
png_write_data
void png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
Definition: pngwio.c:33
png_write_pHYs
void png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int unit_type)
Definition: pngwutil.c:1721
PNG_HAVE_IDAT
#define PNG_HAVE_IDAT
Definition: pngpriv.h:266
PNG_pCAL
#define PNG_pCAL
Definition: pngpriv.h:449
PNG_MNG_FEATURES_SUPPORTED
#define PNG_MNG_FEATURES_SUPPORTED
Definition: pnglibconf.h:70
png_bytepp
png_byte FAR *FAR * png_bytepp
Definition: pngconf.h:589
PNG_LOMASK
#define PNG_LOMASK
Definition: pngwutil.c:2186
Z_FINISH
#define Z_FINISH
Definition: zlib.h:168
png_uint_32
unsigned long png_uint_32
Definition: pngconf.h:480
PNG_tRNS
#define PNG_tRNS
Definition: pngpriv.h:458
PNG_TEXT_COMPRESSION_NONE
#define PNG_TEXT_COMPRESSION_NONE
Definition: png.h:619
PNGAPI
#define PNGAPI
Definition: pngconf.h:256
png_structp
png_struct FAR * png_structp
Definition: png.h:797
png_write_tIME
void png_write_tIME(png_structp png_ptr, png_const_timep mod_time)
Definition: pngwutil.c:1746
png_write_cHRM_fixed
void png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, png_fixed_point blue_y)
Definition: pngwutil.c:1076
png_write_tEXt
void png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len)
Definition: pngwutil.c:1408
PNG_COLOR_MASK_COLOR
#define PNG_COLOR_MASK_COLOR
Definition: png.h:685
PNG_ITXT_COMPRESSION_NONE
#define PNG_ITXT_COMPRESSION_NONE
Definition: png.h:621
png_write_flush
void PNGAPI png_write_flush(png_structp png_ptr)
Definition: pngwrite.c:852
png_write_find_filter
void png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
Definition: pngwutil.c:2189
PNG_gAMA
#define PNG_gAMA
Definition: pngpriv.h:444
png_byte
unsigned char png_byte
Definition: pngconf.h:485
png_uint_16
unsigned short png_uint_16
Definition: pngconf.h:483
PNG_FILTER_VALUE_SUB
#define PNG_FILTER_VALUE_SUB
Definition: png.h:1318
PNG_hIST
#define PNG_hIST
Definition: pngpriv.h:445
png_write_IHDR
void png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int compression_type, int filter_type, int interlace_type)
Definition: pngwutil.c:449
PNG_COLOR_TYPE_GRAY
#define PNG_COLOR_TYPE_GRAY
Definition: png.h:689
png_write_filtered_row
void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
Definition: pngwutil.c:2860
png_sPLT_entryp
png_sPLT_entry FAR * png_sPLT_entryp
Definition: png.h:564
PNG_HAVE_IHDR
#define PNG_HAVE_IHDR
Definition: pngpriv.h:264
png_warning
void PNGAPI png_warning(png_structp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:108
png_check_cHRM_fixed
int png_check_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, png_fixed_point blue_y)
Definition: png.c:671
PNG_ALL_FILTERS
#define PNG_ALL_FILTERS
Definition: png.h:1311
Z_STREAM_END
#define Z_STREAM_END
Definition: zlib.h:174
PNG_oFFs
#define PNG_oFFs
Definition: pngpriv.h:448
PNG_IO_CHUNK_HDR
#define PNG_IO_CHUNK_HDR
Definition: png.h:2108
PNG_IO_SIGNATURE
#define PNG_IO_SIGNATURE
Definition: png.h:2107
png_const_bytep
PNG_CONST png_byte FAR * png_const_bytep
Definition: pngconf.h:563
PNG_IHDR
#define PNG_IHDR
Definition: pngpriv.h:438
PNG_sBIT
#define PNG_sBIT
Definition: pngpriv.h:452
png_debug1
#define png_debug1(l, m, p1)
Definition: pngdebug.h:152
compression_state::max_output_ptr
int max_output_ptr
Definition: pngwutil.c:207
PNG_FILTER_UP
#define PNG_FILTER_UP
Definition: png.h:1308
png_strlen
#define png_strlen
Definition: pngpriv.h:224
PNG_tIME
#define PNG_tIME
Definition: pngpriv.h:457
PNG_FILTER_AVG
#define PNG_FILTER_AVG
Definition: png.h:1309
Z_MEM_ERROR
#define Z_MEM_ERROR
Definition: zlib.h:179
PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS
#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS
Definition: pngpriv.h:325
PNG_EQUATION_LAST
#define PNG_EQUATION_LAST
Definition: png.h:722
PNG_RESOLUTION_LAST
#define PNG_RESOLUTION_LAST
Definition: png.h:733
png_const_color_16p
PNG_CONST png_color_16 FAR * png_const_color_16p
Definition: png.h:537
PNG_IO_CHUNK_CRC
#define PNG_IO_CHUNK_CRC
Definition: png.h:2110
png_write_iCCP
void png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, png_const_charp profile, int profile_len)
Definition: pngwutil.c:848
Z_BINARY
#define Z_BINARY
Definition: zlib.h:199
PNG_FILTER_VALUE_UP
#define PNG_FILTER_VALUE_UP
Definition: png.h:1319
deflate
int ZEXPORT deflate(z_streamp strm, int flush)
Definition: deflate.c:582
png_save_uint_32
void PNGAPI png_save_uint_32(png_bytep buf, png_uint_32 i)
Definition: pngwutil.c:24
PNG_FLAG_ZLIB_CUSTOM_METHOD
#define PNG_FLAG_ZLIB_CUSTOM_METHOD
Definition: pngpriv.h:326
png_check_keyword
png_size_t png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)
Definition: pngwutil.c:1282
PNG_FLAG_MNG_FILTER_64
#define PNG_FLAG_MNG_FILTER_64
Definition: png.h:874
PNG_IO_WRITING
#define PNG_IO_WRITING
Definition: png.h:2106
PNG_INTERLACE
#define PNG_INTERLACE
Definition: pngpriv.h:281
png_bytep
png_byte FAR * png_bytep
Definition: pngconf.h:562
PNG_FLAG_ZLIB_CUSTOM_LEVEL
#define PNG_FLAG_ZLIB_CUSTOM_LEVEL
Definition: pngpriv.h:323
PNG_sRGB
#define PNG_sRGB
Definition: pngpriv.h:454
png_write_chunk_end
void PNGAPI png_write_chunk_end(png_structp png_ptr)
Definition: pngwutil.c:176
pngpriv.h
PNG_FILTER_TYPE_BASE
#define PNG_FILTER_TYPE_BASE
Definition: png.h:703
PNG_COLOR_MASK_ALPHA
#define PNG_COLOR_MASK_ALPHA
Definition: png.h:686
Z_VERSION_ERROR
#define Z_VERSION_ERROR
Definition: zlib.h:181
png_row_infop
png_row_info FAR * png_row_infop
Definition: png.h:784
PNG_COMPRESSION_TYPE_BASE
#define PNG_COMPRESSION_TYPE_BASE
Definition: png.h:699
PNG_pHYs
#define PNG_pHYs
Definition: pngpriv.h:451
png_write_sRGB
void png_write_sRGB(png_structp png_ptr, int srgb_intent)
Definition: pngwutil.c:829
PNG_HISHIFT
#define PNG_HISHIFT
Definition: pngwutil.c:2185
png_write_sig
void PNGAPI png_write_sig(png_structp png_ptr)
Definition: pngwutil.c:68
PNG_HAVE_IEND
#define PNG_HAVE_IEND
Definition: pngpriv.h:268
png_write_tRNS
void png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, png_const_color_16p tran, int num_trans, int color_type)
Definition: pngwutil.c:1112
png_write_IEND
void png_write_IEND(png_structp png_ptr)
Definition: pngwutil.c:800
PNG_HAVE_PLTE
#define PNG_HAVE_PLTE
Definition: pngpriv.h:265
png_write_iTXt
void png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, png_const_charp lang, png_const_charp lang_key, png_const_charp text)
Definition: pngwutil.c:1512
png_fixed_point
png_int_32 png_fixed_point
Definition: pngconf.h:557
png_charpp
char FAR *FAR * png_charpp
Definition: pngconf.h:595
PNG_IDAT
#define PNG_IDAT
Definition: pngpriv.h:439
Z_OK
#define Z_OK
Definition: zlib.h:173
PNG_FILTER_VALUE_NONE
#define PNG_FILTER_VALUE_NONE
Definition: png.h:1317
png_calculate_crc
void png_calculate_crc(png_structp png_ptr, png_const_bytep ptr, png_size_t length)
Definition: png.c:119
png_size_t
size_t png_size_t
Definition: pngconf.h:490
png_save_uint_16
void PNGAPI png_save_uint_16(png_bytep buf, unsigned int i)
Definition: pngwutil.c:54
data
JSAMPIMAGE data
Definition: jpeglib.h:945
PNG_INTRAPIXEL_DIFFERENCING
#define PNG_INTRAPIXEL_DIFFERENCING
Definition: png.h:704
PNG_FLAG_MNG_EMPTY_PLTE
#define PNG_FLAG_MNG_EMPTY_PLTE
Definition: png.h:873
png_write_hIST
void png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist)
Definition: pngwutil.c:1240
png_write_chunk
void PNGAPI png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, png_const_bytep data, png_size_t length)
Definition: pngwutil.c:95
png_const_sPLT_tp
PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp
Definition: png.h:581
Z_DEFAULT_STRATEGY
#define Z_DEFAULT_STRATEGY
Definition: zlib.h:196
png_uint_32p
png_uint_32 FAR * png_uint_32p
Definition: pngconf.h:564
deflateReset
int ZEXPORT deflateReset(z_streamp strm)
Definition: deflate.c:353
png_write_finish_row
void png_write_finish_row(png_structp png_ptr)
Definition: pngwutil.c:1880
compression_state::input_len
png_size_t input_len
Definition: pngwutil.c:205
PNG_FILTER_NONE
#define PNG_FILTER_NONE
Definition: png.h:1306
PNG_zTXt
#define PNG_zTXt
Definition: pngpriv.h:459
PNG_MAXSUM
#define PNG_MAXSUM
Definition: pngwutil.c:2184
png_free
void PNGAPI png_free(png_structp png_ptr, png_voidp ptr)
Definition: pngmem.c:569
PNG_COST_SHIFT
#define PNG_COST_SHIFT
Definition: pnglibconf.h:19
PNG_ROWBYTES
#define PNG_ROWBYTES(pixel_bits, width)
Definition: pngpriv.h:382
PNG_HAVE_PNG_SIGNATURE
#define PNG_HAVE_PNG_SIGNATURE
Definition: pngpriv.h:276
png_write_chunk_start
void PNGAPI png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, png_uint_32 length)
Definition: pngwutil.c:111
PNG_iTXt
#define PNG_iTXt
Definition: pngpriv.h:447
png_write_sCAL_s
void png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, png_const_charp height)
Definition: pngwutil.c:1690
png_do_write_interlace
void png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
Definition: pngwutil.c:2008
png_const_uint_16p
PNG_CONST png_uint_16 FAR * png_const_uint_16p
Definition: pngconf.h:569
png_reset_crc
void png_reset_crc(png_structp png_ptr)
Definition: png.c:108
PNG_sPLT
#define PNG_sPLT
Definition: pngpriv.h:453
Z_DEFAULT_COMPRESSION
#define Z_DEFAULT_COMPRESSION
Definition: zlib.h:189
compression_state::output_ptr
png_bytep * output_ptr
Definition: pngwutil.c:208
uInt
unsigned int uInt
Definition: zconf.h:335
png_write_chunk_data
void PNGAPI png_write_chunk_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
Definition: pngwutil.c:156
png_sizeof
#define png_sizeof(x)
Definition: pngconf.h:492
ZLIB_IO_MAX
#define ZLIB_IO_MAX
Definition: pngpriv.h:372
png_debug2
#define png_debug2(l, m, p1, p2)
Definition: pngdebug.h:155
png_write_bKGD
void png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type)
Definition: pngwutil.c:1177
PNG_FLAG_ZLIB_CUSTOM_STRATEGY
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY
Definition: pngpriv.h:322