/[pcsx2_0.9.7]/trunk/3rdparty/wxWidgets/src/png/pngwutil.c
ViewVC logotype

Contents of /trunk/3rdparty/wxWidgets/src/png/pngwutil.c

Parent Directory Parent Directory | Revision Log Revision Log


Revision 31 - (show annotations) (download)
Tue Sep 7 03:24:11 2010 UTC (10 years, 1 month ago) by william
File MIME type: text/plain
File size: 85086 byte(s)
committing r3113 initial commit again...
1
2 /* pngwutil.c - utilities to write a PNG file
3 *
4 * Last changed in libpng 1.2.39 [August 13, 2009]
5 * Copyright (c) 1998-2009 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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 #define PNG_INTERNAL
15 #include "png.h"
16 #ifdef PNG_WRITE_SUPPORTED
17
18 /* Place a 32-bit number into a buffer in PNG byte order. We work
19 * with unsigned numbers for convenience, although one supported
20 * ancillary chunk uses signed (two's complement) numbers.
21 */
22 void PNGAPI
23 png_save_uint_32(png_bytep buf, png_uint_32 i)
24 {
25 buf[0] = (png_byte)((i >> 24) & 0xff);
26 buf[1] = (png_byte)((i >> 16) & 0xff);
27 buf[2] = (png_byte)((i >> 8) & 0xff);
28 buf[3] = (png_byte)(i & 0xff);
29 }
30
31 /* The png_save_int_32 function assumes integers are stored in two's
32 * complement format. If this isn't the case, then this routine needs to
33 * be modified to write data in two's complement format.
34 */
35 void PNGAPI
36 png_save_int_32(png_bytep buf, png_int_32 i)
37 {
38 buf[0] = (png_byte)((i >> 24) & 0xff);
39 buf[1] = (png_byte)((i >> 16) & 0xff);
40 buf[2] = (png_byte)((i >> 8) & 0xff);
41 buf[3] = (png_byte)(i & 0xff);
42 }
43
44 /* Place a 16-bit number into a buffer in PNG byte order.
45 * The parameter is declared unsigned int, not png_uint_16,
46 * just to avoid potential problems on pre-ANSI C compilers.
47 */
48 void PNGAPI
49 png_save_uint_16(png_bytep buf, unsigned int i)
50 {
51 buf[0] = (png_byte)((i >> 8) & 0xff);
52 buf[1] = (png_byte)(i & 0xff);
53 }
54
55 /* Simple function to write the signature. If we have already written
56 * the magic bytes of the signature, or more likely, the PNG stream is
57 * being embedded into another stream and doesn't need its own signature,
58 * we should call png_set_sig_bytes() to tell libpng how many of the
59 * bytes have already been written.
60 */
61 void /* PRIVATE */
62 png_write_sig(png_structp png_ptr)
63 {
64 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
65
66 /* Write the rest of the 8 byte signature */
67 png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
68 (png_size_t)(8 - png_ptr->sig_bytes));
69 if (png_ptr->sig_bytes < 3)
70 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
71 }
72
73 /* Write a PNG chunk all at once. The type is an array of ASCII characters
74 * representing the chunk name. The array must be at least 4 bytes in
75 * length, and does not need to be null terminated. To be safe, pass the
76 * pre-defined chunk names here, and if you need a new one, define it
77 * where the others are defined. The length is the length of the data.
78 * All the data must be present. If that is not possible, use the
79 * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
80 * functions instead.
81 */
82 void PNGAPI
83 png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
84 png_bytep data, png_size_t length)
85 {
86 if (png_ptr == NULL)
87 return;
88 png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
89 png_write_chunk_data(png_ptr, data, (png_size_t)length);
90 png_write_chunk_end(png_ptr);
91 }
92
93 /* Write the start of a PNG chunk. The type is the chunk type.
94 * The total_length is the sum of the lengths of all the data you will be
95 * passing in png_write_chunk_data().
96 */
97 void PNGAPI
98 png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
99 png_uint_32 length)
100 {
101 png_byte buf[8];
102
103 png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
104 (unsigned long)length);
105 if (png_ptr == NULL)
106 return;
107
108 /* Write the length and the chunk name */
109 png_save_uint_32(buf, length);
110 png_memcpy(buf + 4, chunk_name, 4);
111 png_write_data(png_ptr, buf, (png_size_t)8);
112 /* Put the chunk name into png_ptr->chunk_name */
113 png_memcpy(png_ptr->chunk_name, chunk_name, 4);
114 /* Reset the crc and run it over the chunk name */
115 png_reset_crc(png_ptr);
116 png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
117 }
118
119 /* Write the data of a PNG chunk started with png_write_chunk_start().
120 * Note that multiple calls to this function are allowed, and that the
121 * sum of the lengths from these calls *must* add up to the total_length
122 * given to png_write_chunk_start().
123 */
124 void PNGAPI
125 png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
126 {
127 /* Write the data, and run the CRC over it */
128 if (png_ptr == NULL)
129 return;
130 if (data != NULL && length > 0)
131 {
132 png_write_data(png_ptr, data, length);
133 /* Update the CRC after writing the data,
134 * in case that the user I/O routine alters it.
135 */
136 png_calculate_crc(png_ptr, data, length);
137 }
138 }
139
140 /* Finish a chunk started with png_write_chunk_start(). */
141 void PNGAPI
142 png_write_chunk_end(png_structp png_ptr)
143 {
144 png_byte buf[4];
145
146 if (png_ptr == NULL) return;
147
148 /* Write the crc in a single operation */
149 png_save_uint_32(buf, png_ptr->crc);
150
151 png_write_data(png_ptr, buf, (png_size_t)4);
152 }
153
154 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
155 /* This pair of functions encapsulates the operation of (a) compressing a
156 * text string, and (b) issuing it later as a series of chunk data writes.
157 * The compression_state structure is shared context for these functions
158 * set up by the caller in order to make the whole mess thread-safe.
159 */
160
161 typedef struct
162 {
163 char *input; /* The uncompressed input data */
164 int input_len; /* Its length */
165 int num_output_ptr; /* Number of output pointers used */
166 int max_output_ptr; /* Size of output_ptr */
167 png_charpp output_ptr; /* Array of pointers to output */
168 } compression_state;
169
170 /* Compress given text into storage in the png_ptr structure */
171 static int /* PRIVATE */
172 png_text_compress(png_structp png_ptr,
173 png_charp text, png_size_t text_len, int compression,
174 compression_state *comp)
175 {
176 int ret;
177
178 comp->num_output_ptr = 0;
179 comp->max_output_ptr = 0;
180 comp->output_ptr = NULL;
181 comp->input = NULL;
182 comp->input_len = 0;
183
184 /* We may just want to pass the text right through */
185 if (compression == PNG_TEXT_COMPRESSION_NONE)
186 {
187 comp->input = text;
188 comp->input_len = text_len;
189 return((int)text_len);
190 }
191
192 if (compression >= PNG_TEXT_COMPRESSION_LAST)
193 {
194 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
195 char msg[50];
196 png_snprintf(msg, 50, "Unknown compression type %d", compression);
197 png_warning(png_ptr, msg);
198 #else
199 png_warning(png_ptr, "Unknown compression type");
200 #endif
201 }
202
203 /* We can't write the chunk until we find out how much data we have,
204 * which means we need to run the compressor first and save the
205 * output. This shouldn't be a problem, as the vast majority of
206 * comments should be reasonable, but we will set up an array of
207 * malloc'd pointers to be sure.
208 *
209 * If we knew the application was well behaved, we could simplify this
210 * greatly by assuming we can always malloc an output buffer large
211 * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
212 * and malloc this directly. The only time this would be a bad idea is
213 * if we can't malloc more than 64K and we have 64K of random input
214 * data, or if the input string is incredibly large (although this
215 * wouldn't cause a failure, just a slowdown due to swapping).
216 */
217
218 /* Set up the compression buffers */
219 png_ptr->zstream.avail_in = (uInt)text_len;
220 png_ptr->zstream.next_in = (Bytef *)text;
221 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
222 png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
223
224 /* This is the same compression loop as in png_write_row() */
225 do
226 {
227 /* Compress the data */
228 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
229 if (ret != Z_OK)
230 {
231 /* Error */
232 if (png_ptr->zstream.msg != NULL)
233 png_error(png_ptr, png_ptr->zstream.msg);
234 else
235 png_error(png_ptr, "zlib error");
236 }
237 /* Check to see if we need more room */
238 if (!(png_ptr->zstream.avail_out))
239 {
240 /* Make sure the output array has room */
241 if (comp->num_output_ptr >= comp->max_output_ptr)
242 {
243 int old_max;
244
245 old_max = comp->max_output_ptr;
246 comp->max_output_ptr = comp->num_output_ptr + 4;
247 if (comp->output_ptr != NULL)
248 {
249 png_charpp old_ptr;
250
251 old_ptr = comp->output_ptr;
252 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
253 (png_uint_32)
254 (comp->max_output_ptr * png_sizeof(png_charpp)));
255 png_memcpy(comp->output_ptr, old_ptr, old_max
256 * png_sizeof(png_charp));
257 png_free(png_ptr, old_ptr);
258 }
259 else
260 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
261 (png_uint_32)
262 (comp->max_output_ptr * png_sizeof(png_charp)));
263 }
264
265 /* Save the data */
266 comp->output_ptr[comp->num_output_ptr] =
267 (png_charp)png_malloc(png_ptr,
268 (png_uint_32)png_ptr->zbuf_size);
269 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
270 png_ptr->zbuf_size);
271 comp->num_output_ptr++;
272
273 /* and reset the buffer */
274 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
275 png_ptr->zstream.next_out = png_ptr->zbuf;
276 }
277 /* Continue until we don't have any more to compress */
278 } while (png_ptr->zstream.avail_in);
279
280 /* Finish the compression */
281 do
282 {
283 /* Tell zlib we are finished */
284 ret = deflate(&png_ptr->zstream, Z_FINISH);
285
286 if (ret == Z_OK)
287 {
288 /* Check to see if we need more room */
289 if (!(png_ptr->zstream.avail_out))
290 {
291 /* Check to make sure our output array has room */
292 if (comp->num_output_ptr >= comp->max_output_ptr)
293 {
294 int old_max;
295
296 old_max = comp->max_output_ptr;
297 comp->max_output_ptr = comp->num_output_ptr + 4;
298 if (comp->output_ptr != NULL)
299 {
300 png_charpp old_ptr;
301
302 old_ptr = comp->output_ptr;
303 /* This could be optimized to realloc() */
304 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
305 (png_uint_32)(comp->max_output_ptr *
306 png_sizeof(png_charp)));
307 png_memcpy(comp->output_ptr, old_ptr,
308 old_max * png_sizeof(png_charp));
309 png_free(png_ptr, old_ptr);
310 }
311 else
312 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
313 (png_uint_32)(comp->max_output_ptr *
314 png_sizeof(png_charp)));
315 }
316
317 /* Save the data */
318 comp->output_ptr[comp->num_output_ptr] =
319 (png_charp)png_malloc(png_ptr,
320 (png_uint_32)png_ptr->zbuf_size);
321 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
322 png_ptr->zbuf_size);
323 comp->num_output_ptr++;
324
325 /* and reset the buffer pointers */
326 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
327 png_ptr->zstream.next_out = png_ptr->zbuf;
328 }
329 }
330 else if (ret != Z_STREAM_END)
331 {
332 /* We got an error */
333 if (png_ptr->zstream.msg != NULL)
334 png_error(png_ptr, png_ptr->zstream.msg);
335 else
336 png_error(png_ptr, "zlib error");
337 }
338 } while (ret != Z_STREAM_END);
339
340 /* Text length is number of buffers plus last buffer */
341 text_len = png_ptr->zbuf_size * comp->num_output_ptr;
342 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
343 text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
344
345 return((int)text_len);
346 }
347
348 /* Ship the compressed text out via chunk writes */
349 static void /* PRIVATE */
350 png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
351 {
352 int i;
353
354 /* Handle the no-compression case */
355 if (comp->input)
356 {
357 png_write_chunk_data(png_ptr, (png_bytep)comp->input,
358 (png_size_t)comp->input_len);
359 return;
360 }
361
362 /* Write saved output buffers, if any */
363 for (i = 0; i < comp->num_output_ptr; i++)
364 {
365 png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
366 (png_size_t)png_ptr->zbuf_size);
367 png_free(png_ptr, comp->output_ptr[i]);
368 comp->output_ptr[i]=NULL;
369 }
370 if (comp->max_output_ptr != 0)
371 png_free(png_ptr, comp->output_ptr);
372 comp->output_ptr=NULL;
373 /* Write anything left in zbuf */
374 if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
375 png_write_chunk_data(png_ptr, png_ptr->zbuf,
376 (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
377
378 /* Reset zlib for another zTXt/iTXt or image data */
379 deflateReset(&png_ptr->zstream);
380 png_ptr->zstream.data_type = Z_BINARY;
381 }
382 #endif
383
384 /* Write the IHDR chunk, and update the png_struct with the necessary
385 * information. Note that the rest of this code depends upon this
386 * information being correct.
387 */
388 void /* PRIVATE */
389 png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
390 int bit_depth, int color_type, int compression_type, int filter_type,
391 int interlace_type)
392 {
393 #ifdef PNG_USE_LOCAL_ARRAYS
394 PNG_IHDR;
395 #endif
396 int ret;
397
398 png_byte buf[13]; /* Buffer to store the IHDR info */
399
400 png_debug(1, "in png_write_IHDR");
401 /* Check that we have valid input data from the application info */
402 switch (color_type)
403 {
404 case PNG_COLOR_TYPE_GRAY:
405 switch (bit_depth)
406 {
407 case 1:
408 case 2:
409 case 4:
410 case 8:
411 case 16: png_ptr->channels = 1; break;
412 default: png_error(png_ptr, "Invalid bit depth for grayscale image");
413 }
414 break;
415 case PNG_COLOR_TYPE_RGB:
416 if (bit_depth != 8 && bit_depth != 16)
417 png_error(png_ptr, "Invalid bit depth for RGB image");
418 png_ptr->channels = 3;
419 break;
420 case PNG_COLOR_TYPE_PALETTE:
421 switch (bit_depth)
422 {
423 case 1:
424 case 2:
425 case 4:
426 case 8: png_ptr->channels = 1; break;
427 default: png_error(png_ptr, "Invalid bit depth for paletted image");
428 }
429 break;
430 case PNG_COLOR_TYPE_GRAY_ALPHA:
431 if (bit_depth != 8 && bit_depth != 16)
432 png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
433 png_ptr->channels = 2;
434 break;
435 case PNG_COLOR_TYPE_RGB_ALPHA:
436 if (bit_depth != 8 && bit_depth != 16)
437 png_error(png_ptr, "Invalid bit depth for RGBA image");
438 png_ptr->channels = 4;
439 break;
440 default:
441 png_error(png_ptr, "Invalid image color type specified");
442 }
443
444 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
445 {
446 png_warning(png_ptr, "Invalid compression type specified");
447 compression_type = PNG_COMPRESSION_TYPE_BASE;
448 }
449
450 /* Write filter_method 64 (intrapixel differencing) only if
451 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
452 * 2. Libpng did not write a PNG signature (this filter_method is only
453 * used in PNG datastreams that are embedded in MNG datastreams) and
454 * 3. The application called png_permit_mng_features with a mask that
455 * included PNG_FLAG_MNG_FILTER_64 and
456 * 4. The filter_method is 64 and
457 * 5. The color_type is RGB or RGBA
458 */
459 if (
460 #if defined(PNG_MNG_FEATURES_SUPPORTED)
461 !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
462 ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
463 (color_type == PNG_COLOR_TYPE_RGB ||
464 color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
465 (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
466 #endif
467 filter_type != PNG_FILTER_TYPE_BASE)
468 {
469 png_warning(png_ptr, "Invalid filter type specified");
470 filter_type = PNG_FILTER_TYPE_BASE;
471 }
472
473 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
474 if (interlace_type != PNG_INTERLACE_NONE &&
475 interlace_type != PNG_INTERLACE_ADAM7)
476 {
477 png_warning(png_ptr, "Invalid interlace type specified");
478 interlace_type = PNG_INTERLACE_ADAM7;
479 }
480 #else
481 interlace_type=PNG_INTERLACE_NONE;
482 #endif
483
484 /* Save the relevent information */
485 png_ptr->bit_depth = (png_byte)bit_depth;
486 png_ptr->color_type = (png_byte)color_type;
487 png_ptr->interlaced = (png_byte)interlace_type;
488 #if defined(PNG_MNG_FEATURES_SUPPORTED)
489 png_ptr->filter_type = (png_byte)filter_type;
490 #endif
491 png_ptr->compression_type = (png_byte)compression_type;
492 png_ptr->width = width;
493 png_ptr->height = height;
494
495 png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
496 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
497 /* Set the usr info, so any transformations can modify it */
498 png_ptr->usr_width = png_ptr->width;
499 png_ptr->usr_bit_depth = png_ptr->bit_depth;
500 png_ptr->usr_channels = png_ptr->channels;
501
502 /* Pack the header information into the buffer */
503 png_save_uint_32(buf, width);
504 png_save_uint_32(buf + 4, height);
505 buf[8] = (png_byte)bit_depth;
506 buf[9] = (png_byte)color_type;
507 buf[10] = (png_byte)compression_type;
508 buf[11] = (png_byte)filter_type;
509 buf[12] = (png_byte)interlace_type;
510
511 /* Write the chunk */
512 png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
513
514 /* Initialize zlib with PNG info */
515 png_ptr->zstream.zalloc = png_zalloc;
516 png_ptr->zstream.zfree = png_zfree;
517 png_ptr->zstream.opaque = (voidpf)png_ptr;
518 if (!(png_ptr->do_filter))
519 {
520 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
521 png_ptr->bit_depth < 8)
522 png_ptr->do_filter = PNG_FILTER_NONE;
523 else
524 png_ptr->do_filter = PNG_ALL_FILTERS;
525 }
526 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
527 {
528 if (png_ptr->do_filter != PNG_FILTER_NONE)
529 png_ptr->zlib_strategy = Z_FILTERED;
530 else
531 png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
532 }
533 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
534 png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
535 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
536 png_ptr->zlib_mem_level = 8;
537 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
538 png_ptr->zlib_window_bits = 15;
539 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
540 png_ptr->zlib_method = 8;
541 ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
542 png_ptr->zlib_method, png_ptr->zlib_window_bits,
543 png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
544 if (ret != Z_OK)
545 {
546 if (ret == Z_VERSION_ERROR) png_error(png_ptr,
547 "zlib failed to initialize compressor -- version error");
548 if (ret == Z_STREAM_ERROR) png_error(png_ptr,
549 "zlib failed to initialize compressor -- stream error");
550 if (ret == Z_MEM_ERROR) png_error(png_ptr,
551 "zlib failed to initialize compressor -- mem error");
552 png_error(png_ptr, "zlib failed to initialize compressor");
553 }
554 png_ptr->zstream.next_out = png_ptr->zbuf;
555 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
556 /* libpng is not interested in zstream.data_type */
557 /* Set it to a predefined value, to avoid its evaluation inside zlib */
558 png_ptr->zstream.data_type = Z_BINARY;
559
560 png_ptr->mode = PNG_HAVE_IHDR;
561 }
562
563 /* Write the palette. We are careful not to trust png_color to be in the
564 * correct order for PNG, so people can redefine it to any convenient
565 * structure.
566 */
567 void /* PRIVATE */
568 png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
569 {
570 #ifdef PNG_USE_LOCAL_ARRAYS
571 PNG_PLTE;
572 #endif
573 png_uint_32 i;
574 png_colorp pal_ptr;
575 png_byte buf[3];
576
577 png_debug(1, "in png_write_PLTE");
578 if ((
579 #if defined(PNG_MNG_FEATURES_SUPPORTED)
580 !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
581 #endif
582 num_pal == 0) || num_pal > 256)
583 {
584 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
585 {
586 png_error(png_ptr, "Invalid number of colors in palette");
587 }
588 else
589 {
590 png_warning(png_ptr, "Invalid number of colors in palette");
591 return;
592 }
593 }
594
595 if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
596 {
597 png_warning(png_ptr,
598 "Ignoring request to write a PLTE chunk in grayscale PNG");
599 return;
600 }
601
602 png_ptr->num_palette = (png_uint_16)num_pal;
603 png_debug1(3, "num_palette = %d", png_ptr->num_palette);
604
605 png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
606 (png_uint_32)(num_pal * 3));
607 #ifndef PNG_NO_POINTER_INDEXING
608 for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
609 {
610 buf[0] = pal_ptr->red;
611 buf[1] = pal_ptr->green;
612 buf[2] = pal_ptr->blue;
613 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
614 }
615 #else
616 /* This is a little slower but some buggy compilers need to do this instead */
617 pal_ptr=palette;
618 for (i = 0; i < num_pal; i++)
619 {
620 buf[0] = pal_ptr[i].red;
621 buf[1] = pal_ptr[i].green;
622 buf[2] = pal_ptr[i].blue;
623 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
624 }
625 #endif
626 png_write_chunk_end(png_ptr);
627 png_ptr->mode |= PNG_HAVE_PLTE;
628 }
629
630 /* Write an IDAT chunk */
631 void /* PRIVATE */
632 png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
633 {
634 #ifdef PNG_USE_LOCAL_ARRAYS
635 PNG_IDAT;
636 #endif
637 png_debug(1, "in png_write_IDAT");
638
639 /* Optimize the CMF field in the zlib stream. */
640 /* This hack of the zlib stream is compliant to the stream specification. */
641 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
642 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
643 {
644 unsigned int z_cmf = data[0]; /* zlib compression method and flags */
645 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
646 {
647 /* Avoid memory underflows and multiplication overflows.
648 *
649 * The conditions below are practically always satisfied;
650 * however, they still must be checked.
651 */
652 if (length >= 2 &&
653 png_ptr->height < 16384 && png_ptr->width < 16384)
654 {
655 png_uint_32 uncompressed_idat_size = png_ptr->height *
656 ((png_ptr->width *
657 png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
658 unsigned int z_cinfo = z_cmf >> 4;
659 unsigned int half_z_window_size = 1 << (z_cinfo + 7);
660 while (uncompressed_idat_size <= half_z_window_size &&
661 half_z_window_size >= 256)
662 {
663 z_cinfo--;
664 half_z_window_size >>= 1;
665 }
666 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
667 if (data[0] != (png_byte)z_cmf)
668 {
669 data[0] = (png_byte)z_cmf;
670 data[1] &= 0xe0;
671 data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
672 }
673 }
674 }
675 else
676 png_error(png_ptr,
677 "Invalid zlib compression method or flags in IDAT");
678 }
679
680 png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
681 png_ptr->mode |= PNG_HAVE_IDAT;
682 }
683
684 /* Write an IEND chunk */
685 void /* PRIVATE */
686 png_write_IEND(png_structp png_ptr)
687 {
688 #ifdef PNG_USE_LOCAL_ARRAYS
689 PNG_IEND;
690 #endif
691 png_debug(1, "in png_write_IEND");
692 png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
693 (png_size_t)0);
694 png_ptr->mode |= PNG_HAVE_IEND;
695 }
696
697 #if defined(PNG_WRITE_gAMA_SUPPORTED)
698 /* Write a gAMA chunk */
699 #ifdef PNG_FLOATING_POINT_SUPPORTED
700 void /* PRIVATE */
701 png_write_gAMA(png_structp png_ptr, double file_gamma)
702 {
703 #ifdef PNG_USE_LOCAL_ARRAYS
704 PNG_gAMA;
705 #endif
706 png_uint_32 igamma;
707 png_byte buf[4];
708
709 png_debug(1, "in png_write_gAMA");
710 /* file_gamma is saved in 1/100,000ths */
711 igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
712 png_save_uint_32(buf, igamma);
713 png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
714 }
715 #endif
716 #ifdef PNG_FIXED_POINT_SUPPORTED
717 void /* PRIVATE */
718 png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
719 {
720 #ifdef PNG_USE_LOCAL_ARRAYS
721 PNG_gAMA;
722 #endif
723 png_byte buf[4];
724
725 png_debug(1, "in png_write_gAMA");
726 /* file_gamma is saved in 1/100,000ths */
727 png_save_uint_32(buf, (png_uint_32)file_gamma);
728 png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
729 }
730 #endif
731 #endif
732
733 #if defined(PNG_WRITE_sRGB_SUPPORTED)
734 /* Write a sRGB chunk */
735 void /* PRIVATE */
736 png_write_sRGB(png_structp png_ptr, int srgb_intent)
737 {
738 #ifdef PNG_USE_LOCAL_ARRAYS
739 PNG_sRGB;
740 #endif
741 png_byte buf[1];
742
743 png_debug(1, "in png_write_sRGB");
744 if (srgb_intent >= PNG_sRGB_INTENT_LAST)
745 png_warning(png_ptr,
746 "Invalid sRGB rendering intent specified");
747 buf[0]=(png_byte)srgb_intent;
748 png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
749 }
750 #endif
751
752 #if defined(PNG_WRITE_iCCP_SUPPORTED)
753 /* Write an iCCP chunk */
754 void /* PRIVATE */
755 png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
756 png_charp profile, int profile_len)
757 {
758 #ifdef PNG_USE_LOCAL_ARRAYS
759 PNG_iCCP;
760 #endif
761 png_size_t name_len;
762 png_charp new_name;
763 compression_state comp;
764 int embedded_profile_len = 0;
765
766 png_debug(1, "in png_write_iCCP");
767
768 comp.num_output_ptr = 0;
769 comp.max_output_ptr = 0;
770 comp.output_ptr = NULL;
771 comp.input = NULL;
772 comp.input_len = 0;
773
774 if ((name_len = png_check_keyword(png_ptr, name,
775 &new_name)) == 0)
776 return;
777
778 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
779 png_warning(png_ptr, "Unknown compression type in iCCP chunk");
780
781 if (profile == NULL)
782 profile_len = 0;
783
784 if (profile_len > 3)
785 embedded_profile_len =
786 ((*( (png_bytep)profile ))<<24) |
787 ((*( (png_bytep)profile + 1))<<16) |
788 ((*( (png_bytep)profile + 2))<< 8) |
789 ((*( (png_bytep)profile + 3)) );
790
791 if (embedded_profile_len < 0)
792 {
793 png_warning(png_ptr,
794 "Embedded profile length in iCCP chunk is negative");
795 png_free(png_ptr, new_name);
796 return;
797 }
798
799 if (profile_len < embedded_profile_len)
800 {
801 png_warning(png_ptr,
802 "Embedded profile length too large in iCCP chunk");
803 png_free(png_ptr, new_name);
804 return;
805 }
806
807 if (profile_len > embedded_profile_len)
808 {
809 png_warning(png_ptr,
810 "Truncating profile to actual length in iCCP chunk");
811 profile_len = embedded_profile_len;
812 }
813
814 if (profile_len)
815 profile_len = png_text_compress(png_ptr, profile,
816 (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
817
818 /* Make sure we include the NULL after the name and the compression type */
819 png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
820 (png_uint_32)(name_len + profile_len + 2));
821 new_name[name_len + 1] = 0x00;
822 png_write_chunk_data(png_ptr, (png_bytep)new_name,
823 (png_size_t)(name_len + 2));
824
825 if (profile_len)
826 png_write_compressed_data_out(png_ptr, &comp);
827
828 png_write_chunk_end(png_ptr);
829 png_free(png_ptr, new_name);
830 }
831 #endif
832
833 #if defined(PNG_WRITE_sPLT_SUPPORTED)
834 /* Write a sPLT chunk */
835 void /* PRIVATE */
836 png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
837 {
838 #ifdef PNG_USE_LOCAL_ARRAYS
839 PNG_sPLT;
840 #endif
841 png_size_t name_len;
842 png_charp new_name;
843 png_byte entrybuf[10];
844 int entry_size = (spalette->depth == 8 ? 6 : 10);
845 int palette_size = entry_size * spalette->nentries;
846 png_sPLT_entryp ep;
847 #ifdef PNG_NO_POINTER_INDEXING
848 int i;
849 #endif
850
851 png_debug(1, "in png_write_sPLT");
852 if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
853 return;
854
855 /* Make sure we include the NULL after the name */
856 png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
857 (png_uint_32)(name_len + 2 + palette_size));
858 png_write_chunk_data(png_ptr, (png_bytep)new_name,
859 (png_size_t)(name_len + 1));
860 png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
861
862 /* Loop through each palette entry, writing appropriately */
863 #ifndef PNG_NO_POINTER_INDEXING
864 for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
865 {
866 if (spalette->depth == 8)
867 {
868 entrybuf[0] = (png_byte)ep->red;
869 entrybuf[1] = (png_byte)ep->green;
870 entrybuf[2] = (png_byte)ep->blue;
871 entrybuf[3] = (png_byte)ep->alpha;
872 png_save_uint_16(entrybuf + 4, ep->frequency);
873 }
874 else
875 {
876 png_save_uint_16(entrybuf + 0, ep->red);
877 png_save_uint_16(entrybuf + 2, ep->green);
878 png_save_uint_16(entrybuf + 4, ep->blue);
879 png_save_uint_16(entrybuf + 6, ep->alpha);
880 png_save_uint_16(entrybuf + 8, ep->frequency);
881 }
882 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
883 }
884 #else
885 ep=spalette->entries;
886 for (i=0; i>spalette->nentries; i++)
887 {
888 if (spalette->depth == 8)
889 {
890 entrybuf[0] = (png_byte)ep[i].red;
891 entrybuf[1] = (png_byte)ep[i].green;
892 entrybuf[2] = (png_byte)ep[i].blue;
893 entrybuf[3] = (png_byte)ep[i].alpha;
894 png_save_uint_16(entrybuf + 4, ep[i].frequency);
895 }
896 else
897 {
898 png_save_uint_16(entrybuf + 0, ep[i].red);
899 png_save_uint_16(entrybuf + 2, ep[i].green);
900 png_save_uint_16(entrybuf + 4, ep[i].blue);
901 png_save_uint_16(entrybuf + 6, ep[i].alpha);
902 png_save_uint_16(entrybuf + 8, ep[i].frequency);
903 }
904 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
905 }
906 #endif
907
908 png_write_chunk_end(png_ptr);
909 png_free(png_ptr, new_name);
910 }
911 #endif
912
913 #if defined(PNG_WRITE_sBIT_SUPPORTED)
914 /* Write the sBIT chunk */
915 void /* PRIVATE */
916 png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
917 {
918 #ifdef PNG_USE_LOCAL_ARRAYS
919 PNG_sBIT;
920 #endif
921 png_byte buf[4];
922 png_size_t size;
923
924 png_debug(1, "in png_write_sBIT");
925 /* Make sure we don't depend upon the order of PNG_COLOR_8 */
926 if (color_type & PNG_COLOR_MASK_COLOR)
927 {
928 png_byte maxbits;
929
930 maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
931 png_ptr->usr_bit_depth);
932 if (sbit->red == 0 || sbit->red > maxbits ||
933 sbit->green == 0 || sbit->green > maxbits ||
934 sbit->blue == 0 || sbit->blue > maxbits)
935 {
936 png_warning(png_ptr, "Invalid sBIT depth specified");
937 return;
938 }
939 buf[0] = sbit->red;
940 buf[1] = sbit->green;
941 buf[2] = sbit->blue;
942 size = 3;
943 }
944 else
945 {
946 if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
947 {
948 png_warning(png_ptr, "Invalid sBIT depth specified");
949 return;
950 }
951 buf[0] = sbit->gray;
952 size = 1;
953 }
954
955 if (color_type & PNG_COLOR_MASK_ALPHA)
956 {
957 if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
958 {
959 png_warning(png_ptr, "Invalid sBIT depth specified");
960 return;
961 }
962 buf[size++] = sbit->alpha;
963 }
964
965 png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
966 }
967 #endif
968
969 #if defined(PNG_WRITE_cHRM_SUPPORTED)
970 /* Write the cHRM chunk */
971 #ifdef PNG_FLOATING_POINT_SUPPORTED
972 void /* PRIVATE */
973 png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
974 double red_x, double red_y, double green_x, double green_y,
975 double blue_x, double blue_y)
976 {
977 #ifdef PNG_USE_LOCAL_ARRAYS
978 PNG_cHRM;
979 #endif
980 png_byte buf[32];
981
982 png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
983 int_green_x, int_green_y, int_blue_x, int_blue_y;
984
985 png_debug(1, "in png_write_cHRM");
986
987 int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
988 int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
989 int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5);
990 int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5);
991 int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
992 int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
993 int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5);
994 int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5);
995
996 #if !defined(PNG_NO_CHECK_cHRM)
997 if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
998 int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
999 #endif
1000 {
1001 /* Each value is saved in 1/100,000ths */
1002
1003 png_save_uint_32(buf, int_white_x);
1004 png_save_uint_32(buf + 4, int_white_y);
1005
1006 png_save_uint_32(buf + 8, int_red_x);
1007 png_save_uint_32(buf + 12, int_red_y);
1008
1009 png_save_uint_32(buf + 16, int_green_x);
1010 png_save_uint_32(buf + 20, int_green_y);
1011
1012 png_save_uint_32(buf + 24, int_blue_x);
1013 png_save_uint_32(buf + 28, int_blue_y);
1014
1015 png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1016 }
1017 }
1018 #endif
1019 #ifdef PNG_FIXED_POINT_SUPPORTED
1020 void /* PRIVATE */
1021 png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
1022 png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
1023 png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
1024 png_fixed_point blue_y)
1025 {
1026 #ifdef PNG_USE_LOCAL_ARRAYS
1027 PNG_cHRM;
1028 #endif
1029 png_byte buf[32];
1030
1031 png_debug(1, "in png_write_cHRM");
1032 /* Each value is saved in 1/100,000ths */
1033 #if !defined(PNG_NO_CHECK_cHRM)
1034 if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
1035 green_x, green_y, blue_x, blue_y))
1036 #endif
1037 {
1038 png_save_uint_32(buf, (png_uint_32)white_x);
1039 png_save_uint_32(buf + 4, (png_uint_32)white_y);
1040
1041 png_save_uint_32(buf + 8, (png_uint_32)red_x);
1042 png_save_uint_32(buf + 12, (png_uint_32)red_y);
1043
1044 png_save_uint_32(buf + 16, (png_uint_32)green_x);
1045 png_save_uint_32(buf + 20, (png_uint_32)green_y);
1046
1047 png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1048 png_save_uint_32(buf + 28, (png_uint_32)blue_y);
1049
1050 png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1051 }
1052 }
1053 #endif
1054 #endif
1055
1056 #if defined(PNG_WRITE_tRNS_SUPPORTED)
1057 /* Write the tRNS chunk */
1058 void /* PRIVATE */
1059 png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
1060 int num_trans, int color_type)
1061 {
1062 #ifdef PNG_USE_LOCAL_ARRAYS
1063 PNG_tRNS;
1064 #endif
1065 png_byte buf[6];
1066
1067 png_debug(1, "in png_write_tRNS");
1068 if (color_type == PNG_COLOR_TYPE_PALETTE)
1069 {
1070 if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
1071 {
1072 png_warning(png_ptr, "Invalid number of transparent colors specified");
1073 return;
1074 }
1075 /* Write the chunk out as it is */
1076 png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
1077 (png_size_t)num_trans);
1078 }
1079 else if (color_type == PNG_COLOR_TYPE_GRAY)
1080 {
1081 /* One 16 bit value */
1082 if (tran->gray >= (1 << png_ptr->bit_depth))
1083 {
1084 png_warning(png_ptr,
1085 "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1086 return;
1087 }
1088 png_save_uint_16(buf, tran->gray);
1089 png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
1090 }
1091 else if (color_type == PNG_COLOR_TYPE_RGB)
1092 {
1093 /* Three 16 bit values */
1094 png_save_uint_16(buf, tran->red);
1095 png_save_uint_16(buf + 2, tran->green);
1096 png_save_uint_16(buf + 4, tran->blue);
1097 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1098 {
1099 png_warning(png_ptr,
1100 "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1101 return;
1102 }
1103 png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
1104 }
1105 else
1106 {
1107 png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1108 }
1109 }
1110 #endif
1111
1112 #if defined(PNG_WRITE_bKGD_SUPPORTED)
1113 /* Write the background chunk */
1114 void /* PRIVATE */
1115 png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
1116 {
1117 #ifdef PNG_USE_LOCAL_ARRAYS
1118 PNG_bKGD;
1119 #endif
1120 png_byte buf[6];
1121
1122 png_debug(1, "in png_write_bKGD");
1123 if (color_type == PNG_COLOR_TYPE_PALETTE)
1124 {
1125 if (
1126 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1127 (png_ptr->num_palette ||
1128 (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1129 #endif
1130 back->index >= png_ptr->num_palette)
1131 {
1132 png_warning(png_ptr, "Invalid background palette index");
1133 return;
1134 }
1135 buf[0] = back->index;
1136 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
1137 }
1138 else if (color_type & PNG_COLOR_MASK_COLOR)
1139 {
1140 png_save_uint_16(buf, back->red);
1141 png_save_uint_16(buf + 2, back->green);
1142 png_save_uint_16(buf + 4, back->blue);
1143 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1144 {
1145 png_warning(png_ptr,
1146 "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1147 return;
1148 }
1149 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
1150 }
1151 else
1152 {
1153 if (back->gray >= (1 << png_ptr->bit_depth))
1154 {
1155 png_warning(png_ptr,
1156 "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1157 return;
1158 }
1159 png_save_uint_16(buf, back->gray);
1160 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
1161 }
1162 }
1163 #endif
1164
1165 #if defined(PNG_WRITE_hIST_SUPPORTED)
1166 /* Write the histogram */
1167 void /* PRIVATE */
1168 png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
1169 {
1170 #ifdef PNG_USE_LOCAL_ARRAYS
1171 PNG_hIST;
1172 #endif
1173 int i;
1174 png_byte buf[3];
1175
1176 png_debug(1, "in png_write_hIST");
1177 if (num_hist > (int)png_ptr->num_palette)
1178 {
1179 png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
1180 png_ptr->num_palette);
1181 png_warning(png_ptr, "Invalid number of histogram entries specified");
1182 return;
1183 }
1184
1185 png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
1186 (png_uint_32)(num_hist * 2));
1187 for (i = 0; i < num_hist; i++)
1188 {
1189 png_save_uint_16(buf, hist[i]);
1190 png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1191 }
1192 png_write_chunk_end(png_ptr);
1193 }
1194 #endif
1195
1196 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1197 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1198 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1199 * and if invalid, correct the keyword rather than discarding the entire
1200 * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1201 * length, forbids leading or trailing whitespace, multiple internal spaces,
1202 * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1203 *
1204 * The new_key is allocated to hold the corrected keyword and must be freed
1205 * by the calling routine. This avoids problems with trying to write to
1206 * static keywords without having to have duplicate copies of the strings.
1207 */
1208 png_size_t /* PRIVATE */
1209 png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
1210 {
1211 png_size_t key_len;
1212 png_charp kp, dp;
1213 int kflag;
1214 int kwarn=0;
1215
1216 png_debug(1, "in png_check_keyword");
1217 *new_key = NULL;
1218
1219 if (key == NULL || (key_len = png_strlen(key)) == 0)
1220 {
1221 png_warning(png_ptr, "zero length keyword");
1222 return ((png_size_t)0);
1223 }
1224
1225 png_debug1(2, "Keyword to be checked is '%s'", key);
1226
1227 *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1228 if (*new_key == NULL)
1229 {
1230 png_warning(png_ptr, "Out of memory while procesing keyword");
1231 return ((png_size_t)0);
1232 }
1233
1234 /* Replace non-printing characters with a blank and print a warning */
1235 for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
1236 {
1237 if ((png_byte)*kp < 0x20 ||
1238 ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
1239 {
1240 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
1241 char msg[40];
1242
1243 png_snprintf(msg, 40,
1244 "invalid keyword character 0x%02X", (png_byte)*kp);
1245 png_warning(png_ptr, msg);
1246 #else
1247 png_warning(png_ptr, "invalid character in keyword");
1248 #endif
1249 *dp = ' ';
1250 }
1251 else
1252 {
1253 *dp = *kp;
1254 }
1255 }
1256 *dp = '\0';
1257
1258 /* Remove any trailing white space. */
1259 kp = *new_key + key_len - 1;
1260 if (*kp == ' ')
1261 {
1262 png_warning(png_ptr, "trailing spaces removed from keyword");
1263
1264 while (*kp == ' ')
1265 {
1266 *(kp--) = '\0';
1267 key_len--;
1268 }
1269 }
1270
1271 /* Remove any leading white space. */
1272 kp = *new_key;
1273 if (*kp == ' ')
1274 {
1275 png_warning(png_ptr, "leading spaces removed from keyword");
1276
1277 while (*kp == ' ')
1278 {
1279 kp++;
1280 key_len--;
1281 }
1282 }
1283
1284 png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
1285
1286 /* Remove multiple internal spaces. */
1287 for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1288 {
1289 if (*kp == ' ' && kflag == 0)
1290 {
1291 *(dp++) = *kp;
1292 kflag = 1;
1293 }
1294 else if (*kp == ' ')
1295 {
1296 key_len--;
1297 kwarn=1;
1298 }
1299 else
1300 {
1301 *(dp++) = *kp;
1302 kflag = 0;
1303 }
1304 }
1305 *dp = '\0';
1306 if (kwarn)
1307 png_warning(png_ptr, "extra interior spaces removed from keyword");
1308
1309 if (key_len == 0)
1310 {
1311 png_free(png_ptr, *new_key);
1312 *new_key=NULL;
1313 png_warning(png_ptr, "Zero length keyword");
1314 }
1315
1316 if (key_len > 79)
1317 {
1318 png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1319 (*new_key)[79] = '\0';
1320 key_len = 79;
1321 }
1322
1323 return (key_len);
1324 }
1325 #endif
1326
1327 #if defined(PNG_WRITE_tEXt_SUPPORTED)
1328 /* Write a tEXt chunk */
1329 void /* PRIVATE */
1330 png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
1331 png_size_t text_len)
1332 {
1333 #ifdef PNG_USE_LOCAL_ARRAYS
1334 PNG_tEXt;
1335 #endif
1336 png_size_t key_len;
1337 png_charp new_key;
1338
1339 png_debug(1, "in png_write_tEXt");
1340 if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1341 return;
1342
1343 if (text == NULL || *text == '\0')
1344 text_len = 0;
1345 else
1346 text_len = png_strlen(text);
1347
1348 /* Make sure we include the 0 after the key */
1349 png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
1350 (png_uint_32)(key_len + text_len + 1));
1351 /*
1352 * We leave it to the application to meet PNG-1.0 requirements on the
1353 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1354 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1355 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1356 */
1357 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1358 (png_size_t)(key_len + 1));
1359 if (text_len)
1360 png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
1361
1362 png_write_chunk_end(png_ptr);
1363 png_free(png_ptr, new_key);
1364 }
1365 #endif
1366
1367 #if defined(PNG_WRITE_zTXt_SUPPORTED)
1368 /* Write a compressed text chunk */
1369 void /* PRIVATE */
1370 png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
1371 png_size_t text_len, int compression)
1372 {
1373 #ifdef PNG_USE_LOCAL_ARRAYS
1374 PNG_zTXt;
1375 #endif
1376 png_size_t key_len;
1377 char buf[1];
1378 png_charp new_key;
1379 compression_state comp;
1380
1381 png_debug(1, "in png_write_zTXt");
1382
1383 comp.num_output_ptr = 0;
1384 comp.max_output_ptr = 0;
1385 comp.output_ptr = NULL;
1386 comp.input = NULL;
1387 comp.input_len = 0;
1388
1389 if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1390 {
1391 png_free(png_ptr, new_key);
1392 return;
1393 }
1394
1395 if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1396 {
1397 png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1398 png_free(png_ptr, new_key);
1399 return;
1400 }
1401
1402 text_len = png_strlen(text);
1403
1404 /* Compute the compressed data; do it now for the length */
1405 text_len = png_text_compress(png_ptr, text, text_len, compression,
1406 &comp);
1407
1408 /* Write start of chunk */
1409 png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
1410 (png_uint_32)(key_len+text_len + 2));
1411 /* Write key */
1412 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1413 (png_size_t)(key_len + 1));
1414 png_free(png_ptr, new_key);
1415
1416 buf[0] = (png_byte)compression;
1417 /* Write compression */
1418 png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
1419 /* Write the compressed data */
1420 png_write_compressed_data_out(png_ptr, &comp);
1421
1422 /* Close the chunk */
1423 png_write_chunk_end(png_ptr);
1424 }
1425 #endif
1426
1427 #if defined(PNG_WRITE_iTXt_SUPPORTED)
1428 /* Write an iTXt chunk */
1429 void /* PRIVATE */
1430 png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
1431 png_charp lang, png_charp lang_key, png_charp text)
1432 {
1433 #ifdef PNG_USE_LOCAL_ARRAYS
1434 PNG_iTXt;
1435 #endif
1436 png_size_t lang_len, key_len, lang_key_len, text_len;
1437 png_charp new_lang;
1438 png_charp new_key = NULL;
1439 png_byte cbuf[2];
1440 compression_state comp;
1441
1442 png_debug(1, "in png_write_iTXt");
1443
1444 comp.num_output_ptr = 0;
1445 comp.max_output_ptr = 0;
1446 comp.output_ptr = NULL;
1447 comp.input = NULL;
1448
1449 if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1450 return;
1451
1452 if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
1453 {
1454 png_warning(png_ptr, "Empty language field in iTXt chunk");
1455 new_lang = NULL;
1456 lang_len = 0;
1457 }
1458
1459 if (lang_key == NULL)
1460 lang_key_len = 0;
1461 else
1462 lang_key_len = png_strlen(lang_key);
1463
1464 if (text == NULL)
1465 text_len = 0;
1466 else
1467 text_len = png_strlen(text);
1468
1469 /* Compute the compressed data; do it now for the length */
1470 text_len = png_text_compress(png_ptr, text, text_len, compression-2,
1471 &comp);
1472
1473
1474 /* Make sure we include the compression flag, the compression byte,
1475 * and the NULs after the key, lang, and lang_key parts */
1476
1477 png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
1478 (png_uint_32)(
1479 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1480 + key_len
1481 + lang_len
1482 + lang_key_len
1483 + text_len));
1484
1485 /* We leave it to the application to meet PNG-1.0 requirements on the
1486 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1487 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1488 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1489 */
1490 png_write_chunk_data(png_ptr, (png_bytep)new_key,
1491 (png_size_t)(key_len + 1));
1492
1493 /* Set the compression flag */
1494 if (compression == PNG_ITXT_COMPRESSION_NONE || \
1495 compression == PNG_TEXT_COMPRESSION_NONE)
1496 cbuf[0] = 0;
1497 else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1498 cbuf[0] = 1;
1499 /* Set the compression method */
1500 cbuf[1] = 0;
1501 png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
1502
1503 cbuf[0] = 0;
1504 png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
1505 (png_size_t)(lang_len + 1));
1506 png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
1507 (png_size_t)(lang_key_len + 1));
1508 png_write_compressed_data_out(png_ptr, &comp);
1509
1510 png_write_chunk_end(png_ptr);
1511 png_free(png_ptr, new_key);
1512 png_free(png_ptr, new_lang);
1513 }
1514 #endif
1515
1516 #if defined(PNG_WRITE_oFFs_SUPPORTED)
1517 /* Write the oFFs chunk */
1518 void /* PRIVATE */
1519 png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1520 int unit_type)
1521 {
1522 #ifdef PNG_USE_LOCAL_ARRAYS
1523 PNG_oFFs;
1524 #endif
1525 png_byte buf[9];
1526
1527 png_debug(1, "in png_write_oFFs");
1528 if (unit_type >= PNG_OFFSET_LAST)
1529 png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1530
1531 png_save_int_32(buf, x_offset);
1532 png_save_int_32(buf + 4, y_offset);
1533 buf[8] = (png_byte)unit_type;
1534
1535 png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
1536 }
1537 #endif
1538 #if defined(PNG_WRITE_pCAL_SUPPORTED)
1539 /* Write the pCAL chunk (described in the PNG extensions document) */
1540 void /* PRIVATE */
1541 png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1542 png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
1543 {
1544 #ifdef PNG_USE_LOCAL_ARRAYS
1545 PNG_pCAL;
1546 #endif
1547 png_size_t purpose_len, units_len, total_len;
1548 png_uint_32p params_len;
1549 png_byte buf[10];
1550 png_charp new_purpose;
1551 int i;
1552
1553 png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
1554 if (type >= PNG_EQUATION_LAST)
1555 png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1556
1557 purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1558 png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
1559 units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1560 png_debug1(3, "pCAL units length = %d", (int)units_len);
1561 total_len = purpose_len + units_len + 10;
1562
1563 params_len = (png_uint_32p)png_malloc(png_ptr,
1564 (png_uint_32)(nparams * png_sizeof(png_uint_32)));
1565
1566 /* Find the length of each parameter, making sure we don't count the
1567 null terminator for the last parameter. */
1568 for (i = 0; i < nparams; i++)
1569 {
1570 params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1571 png_debug2(3, "pCAL parameter %d length = %lu", i,
1572 (unsigned long) params_len[i]);
1573 total_len += (png_size_t)params_len[i];
1574 }
1575
1576 png_debug1(3, "pCAL total length = %d", (int)total_len);
1577 png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
1578 png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
1579 (png_size_t)purpose_len);
1580 png_save_int_32(buf, X0);
1581 png_save_int_32(buf + 4, X1);
1582 buf[8] = (png_byte)type;
1583 buf[9] = (png_byte)nparams;
1584 png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1585 png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
1586
1587 png_free(png_ptr, new_purpose);
1588
1589 for (i = 0; i < nparams; i++)
1590 {
1591 png_write_chunk_data(png_ptr, (png_bytep)params[i],
1592 (png_size_t)params_len[i]);
1593 }
1594
1595 png_free(png_ptr, params_len);
1596 png_write_chunk_end(png_ptr);
1597 }
1598 #endif
1599
1600 #if defined(PNG_WRITE_sCAL_SUPPORTED)
1601 /* Write the sCAL chunk */
1602 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
1603 void /* PRIVATE */
1604 png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
1605 {
1606 #ifdef PNG_USE_LOCAL_ARRAYS
1607 PNG_sCAL;
1608 #endif
1609 char buf[64];
1610 png_size_t total_len;
1611
1612 png_debug(1, "in png_write_sCAL");
1613
1614 buf[0] = (char)unit;
1615 #if defined(_WIN32_WCE)
1616 /* sprintf() function is not supported on WindowsCE */
1617 {
1618 wchar_t wc_buf[32];
1619 size_t wc_len;
1620 swprintf(wc_buf, TEXT("%12.12e"), width);
1621 wc_len = wcslen(wc_buf);
1622 WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + 1, wc_len, NULL, NULL);
1623 total_len = wc_len + 2;
1624 swprintf(wc_buf, TEXT("%12.12e"), height);
1625 wc_len = wcslen(wc_buf);
1626 WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + total_len, wc_len,
1627 NULL, NULL);
1628 total_len += wc_len;
1629 }
1630 #else
1631 png_snprintf(buf + 1, 63, "%12.12e", width);
1632 total_len = 1 + png_strlen(buf + 1) + 1;
1633 png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
1634 total_len += png_strlen(buf + total_len);
1635 #endif
1636
1637 png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1638 png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
1639 }
1640 #else
1641 #ifdef PNG_FIXED_POINT_SUPPORTED
1642 void /* PRIVATE */
1643 png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
1644 png_charp height)
1645 {
1646 #ifdef PNG_USE_LOCAL_ARRAYS
1647 PNG_sCAL;
1648 #endif
1649 png_byte buf[64];
1650 png_size_t wlen, hlen, total_len;
1651
1652 png_debug(1, "in png_write_sCAL_s");
1653
1654 wlen = png_strlen(width);
1655 hlen = png_strlen(height);
1656 total_len = wlen + hlen + 2;
1657 if (total_len > 64)
1658 {
1659 png_warning(png_ptr, "Can't write sCAL (buffer too small)");
1660 return;
1661 }
1662
1663 buf[0] = (png_byte)unit;
1664 png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
1665 png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
1666
1667 png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1668 png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
1669 }
1670 #endif
1671 #endif
1672 #endif
1673
1674 #if defined(PNG_WRITE_pHYs_SUPPORTED)
1675 /* Write the pHYs chunk */
1676 void /* PRIVATE */
1677 png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1678 png_uint_32 y_pixels_per_unit,
1679 int unit_type)
1680 {
1681 #ifdef PNG_USE_LOCAL_ARRAYS
1682 PNG_pHYs;
1683 #endif
1684 png_byte buf[9];
1685
1686 png_debug(1, "in png_write_pHYs");
1687 if (unit_type >= PNG_RESOLUTION_LAST)
1688 png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1689
1690 png_save_uint_32(buf, x_pixels_per_unit);
1691 png_save_uint_32(buf + 4, y_pixels_per_unit);
1692 buf[8] = (png_byte)unit_type;
1693
1694 png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
1695 }
1696 #endif
1697
1698 #if defined(PNG_WRITE_tIME_SUPPORTED)
1699 /* Write the tIME chunk. Use either png_convert_from_struct_tm()
1700 * or png_convert_from_time_t(), or fill in the structure yourself.
1701 */
1702 void /* PRIVATE */
1703 png_write_tIME(png_structp png_ptr, png_timep mod_time)
1704 {
1705 #ifdef PNG_USE_LOCAL_ARRAYS
1706 PNG_tIME;
1707 #endif
1708 png_byte buf[7];
1709
1710 png_debug(1, "in png_write_tIME");
1711 if (mod_time->month > 12 || mod_time->month < 1 ||
1712 mod_time->day > 31 || mod_time->day < 1 ||
1713 mod_time->hour > 23 || mod_time->second > 60)
1714 {
1715 png_warning(png_ptr, "Invalid time specified for tIME chunk");
1716 return;
1717 }
1718
1719 png_save_uint_16(buf, mod_time->year);
1720 buf[2] = mod_time->month;
1721 buf[3] = mod_time->day;
1722 buf[4] = mod_time->hour;
1723 buf[5] = mod_time->minute;
1724 buf[6] = mod_time->second;
1725
1726 png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
1727 }
1728 #endif
1729
1730 /* Initializes the row writing capability of libpng */
1731 void /* PRIVATE */
1732 png_write_start_row(png_structp png_ptr)
1733 {
1734 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1735 #ifdef PNG_USE_LOCAL_ARRAYS
1736 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1737
1738 /* Start of interlace block */
1739 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1740
1741 /* Offset to next interlace block */
1742 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1743
1744 /* Start of interlace block in the y direction */
1745 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1746
1747 /* Offset to next interlace block in the y direction */
1748 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1749 #endif
1750 #endif
1751
1752 png_size_t buf_size;
1753
1754 png_debug(1, "in png_write_start_row");
1755 buf_size = (png_size_t)(PNG_ROWBYTES(
1756 png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
1757
1758 /* Set up row buffer */
1759 png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
1760 (png_uint_32)buf_size);
1761 png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1762
1763 #ifndef PNG_NO_WRITE_FILTER
1764 /* Set up filtering buffer, if using this filter */
1765 if (png_ptr->do_filter & PNG_FILTER_SUB)
1766 {
1767 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1768 (png_uint_32)(png_ptr->rowbytes + 1));
1769 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1770 }
1771
1772 /* We only need to keep the previous row if we are using one of these. */
1773 if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1774 {
1775 /* Set up previous row buffer */
1776 png_ptr->prev_row = (png_bytep)png_malloc(png_ptr,
1777 (png_uint_32)buf_size);
1778 png_memset(png_ptr->prev_row, 0, buf_size);
1779
1780 if (png_ptr->do_filter & PNG_FILTER_UP)
1781 {
1782 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1783 (png_uint_32)(png_ptr->rowbytes + 1));
1784 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1785 }
1786
1787 if (png_ptr->do_filter & PNG_FILTER_AVG)
1788 {
1789 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1790 (png_uint_32)(png_ptr->rowbytes + 1));
1791 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1792 }
1793
1794 if (png_ptr->do_filter & PNG_FILTER_PAETH)
1795 {
1796 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1797 (png_uint_32)(png_ptr->rowbytes + 1));
1798 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1799 }
1800 }
1801 #endif /* PNG_NO_WRITE_FILTER */
1802
1803 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1804 /* If interlaced, we need to set up width and height of pass */
1805 if (png_ptr->interlaced)
1806 {
1807 if (!(png_ptr->transformations & PNG_INTERLACE))
1808 {
1809 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1810 png_pass_ystart[0]) / png_pass_yinc[0];
1811 png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1812 png_pass_start[0]) / png_pass_inc[0];
1813 }
1814 else
1815 {
1816 png_ptr->num_rows = png_ptr->height;
1817 png_ptr->usr_width = png_ptr->width;
1818 }
1819 }
1820 else
1821 #endif
1822 {
1823 png_ptr->num_rows = png_ptr->height;
1824 png_ptr->usr_width = png_ptr->width;
1825 }
1826 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1827 png_ptr->zstream.next_out = png_ptr->zbuf;
1828 }
1829
1830 /* Internal use only. Called when finished processing a row of data. */
1831 void /* PRIVATE */
1832 png_write_finish_row(png_structp png_ptr)
1833 {
1834 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1835 #ifdef PNG_USE_LOCAL_ARRAYS
1836 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1837
1838 /* Start of interlace block */
1839 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1840
1841 /* Offset to next interlace block */
1842 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1843
1844 /* Start of interlace block in the y direction */
1845 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1846
1847 /* Offset to next interlace block in the y direction */
1848 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1849 #endif
1850 #endif
1851
1852 int ret;
1853
1854 png_debug(1, "in png_write_finish_row");
1855 /* Next row */
1856 png_ptr->row_number++;
1857
1858 /* See if we are done */
1859 if (png_ptr->row_number < png_ptr->num_rows)
1860 return;
1861
1862 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1863 /* If interlaced, go to next pass */
1864 if (png_ptr->interlaced)
1865 {
1866 png_ptr->row_number = 0;
1867 if (png_ptr->transformations & PNG_INTERLACE)
1868 {
1869 png_ptr->pass++;
1870 }
1871 else
1872 {
1873 /* Loop until we find a non-zero width or height pass */
1874 do
1875 {
1876 png_ptr->pass++;
1877 if (png_ptr->pass >= 7)
1878 break;
1879 png_ptr->usr_width = (png_ptr->width +
1880 png_pass_inc[png_ptr->pass] - 1 -
1881 png_pass_start[png_ptr->pass]) /
1882 png_pass_inc[png_ptr->pass];
1883 png_ptr->num_rows = (png_ptr->height +
1884 png_pass_yinc[png_ptr->pass] - 1 -
1885 png_pass_ystart[png_ptr->pass]) /
1886 png_pass_yinc[png_ptr->pass];
1887 if (png_ptr->transformations & PNG_INTERLACE)
1888 break;
1889 } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1890
1891 }
1892
1893 /* Reset the row above the image for the next pass */
1894 if (png_ptr->pass < 7)
1895 {
1896 if (png_ptr->prev_row != NULL)
1897 png_memset(png_ptr->prev_row, 0,
1898 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
1899 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
1900 return;
1901 }
1902 }
1903 #endif
1904
1905 /* If we get here, we've just written the last row, so we need
1906 to flush the compressor */
1907 do
1908 {
1909 /* Tell the compressor we are done */
1910 ret = deflate(&png_ptr->zstream, Z_FINISH);
1911 /* Check for an error */
1912 if (ret == Z_OK)
1913 {
1914 /* Check to see if we need more room */
1915 if (!(png_ptr->zstream.avail_out))
1916 {
1917 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1918 png_ptr->zstream.next_out = png_ptr->zbuf;
1919 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1920 }
1921 }
1922 else if (ret != Z_STREAM_END)
1923 {
1924 if (png_ptr->zstream.msg != NULL)
1925 png_error(png_ptr, png_ptr->zstream.msg);
1926 else
1927 png_error(png_ptr, "zlib error");
1928 }
1929 } while (ret != Z_STREAM_END);
1930
1931 /* Write any extra space */
1932 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1933 {
1934 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1935 png_ptr->zstream.avail_out);
1936 }
1937
1938 deflateReset(&png_ptr->zstream);
1939 png_ptr->zstream.data_type = Z_BINARY;
1940 }
1941
1942 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
1943 /* Pick out the correct pixels for the interlace pass.
1944 * The basic idea here is to go through the row with a source
1945 * pointer and a destination pointer (sp and dp), and copy the
1946 * correct pixels for the pass. As the row gets compacted,
1947 * sp will always be >= dp, so we should never overwrite anything.
1948 * See the default: case for the easiest code to understand.
1949 */
1950 void /* PRIVATE */
1951 png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
1952 {
1953 #ifdef PNG_USE_LOCAL_ARRAYS
1954 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1955
1956 /* Start of interlace block */
1957 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1958
1959 /* Offset to next interlace block */
1960 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1961 #endif
1962
1963 png_debug(1, "in png_do_write_interlace");
1964 /* We don't have to do anything on the last pass (6) */
1965 #if defined(PNG_USELESS_TESTS_SUPPORTED)
1966 if (row != NULL && row_info != NULL && pass < 6)
1967 #else
1968 if (pass < 6)
1969 #endif
1970 {
1971 /* Each pixel depth is handled separately */
1972 switch (row_info->pixel_depth)
1973 {
1974 case 1:
1975 {
1976 png_bytep sp;
1977 png_bytep dp;
1978 int shift;
1979 int d;
1980 int value;
1981 png_uint_32 i;
1982 png_uint_32 row_width = row_info->width;
1983
1984 dp = row;
1985 d = 0;
1986 shift = 7;
1987 for (i = png_pass_start[pass]; i < row_width;
1988 i += png_pass_inc[pass])
1989 {
1990 sp = row + (png_size_t)(i >> 3);
1991 value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
1992 d |= (value << shift);
1993
1994 if (shift == 0)
1995 {
1996 shift = 7;
1997 *dp++ = (png_byte)d;
1998 d = 0;
1999 }
2000 else
2001 shift--;
2002
2003 }
2004 if (shift != 7)
2005 *dp = (png_byte)d;
2006 break;
2007 }
2008 case 2:
2009 {
2010 png_bytep sp;
2011 png_bytep dp;
2012 int shift;
2013 int d;
2014 int value;
2015 png_uint_32 i;
2016 png_uint_32 row_width = row_info->width;
2017
2018 dp = row;
2019 shift = 6;
2020 d = 0;
2021 for (i = png_pass_start[pass]; i < row_width;
2022 i += png_pass_inc[pass])
2023 {
2024 sp = row + (png_size_t)(i >> 2);
2025 value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
2026 d |= (value << shift);
2027
2028 if (shift == 0)
2029 {
2030 shift = 6;
2031 *dp++ = (png_byte)d;
2032 d = 0;
2033 }
2034 else
2035 shift -= 2;
2036 }
2037 if (shift != 6)
2038 *dp = (png_byte)d;
2039 break;
2040 }
2041 case 4:
2042 {
2043 png_bytep sp;
2044 png_bytep dp;
2045 int shift;
2046 int d;
2047 int value;
2048 png_uint_32 i;
2049 png_uint_32 row_width = row_info->width;
2050
2051 dp = row;
2052 shift = 4;
2053 d = 0;
2054 for (i = png_pass_start[pass]; i < row_width;
2055 i += png_pass_inc[pass])
2056 {
2057 sp = row + (png_size_t)(i >> 1);
2058 value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
2059 d |= (value << shift);
2060
2061 if (shift == 0)
2062 {
2063 shift = 4;
2064 *dp++ = (png_byte)d;
2065 d = 0;
2066 }
2067 else
2068 shift -= 4;
2069 }
2070 if (shift != 4)
2071 *dp = (png_byte)d;
2072 break;
2073 }
2074 default:
2075 {
2076 png_bytep sp;
2077 png_bytep dp;
2078 png_uint_32 i;
2079 png_uint_32 row_width = row_info->width;
2080 png_size_t pixel_bytes;
2081
2082 /* Start at the beginning */
2083 dp = row;
2084 /* Find out how many bytes each pixel takes up */
2085 pixel_bytes = (row_info->pixel_depth >> 3);
2086 /* Loop through the row, only looking at the pixels that
2087 matter */
2088 for (i = png_pass_start[pass]; i < row_width;
2089 i += png_pass_inc[pass])
2090 {
2091 /* Find out where the original pixel is */
2092 sp = row + (png_size_t)i * pixel_bytes;
2093 /* Move the pixel */
2094 if (dp != sp)
2095 png_memcpy(dp, sp, pixel_bytes);
2096 /* Next pixel */
2097 dp += pixel_bytes;
2098 }
2099 break;
2100 }
2101 }
2102 /* Set new row width */
2103 row_info->width = (row_info->width +
2104 png_pass_inc[pass] - 1 -
2105 png_pass_start[pass]) /
2106 png_pass_inc[pass];
2107 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2108 row_info->width);
2109 }
2110 }
2111 #endif
2112
2113 /* This filters the row, chooses which filter to use, if it has not already
2114 * been specified by the application, and then writes the row out with the
2115 * chosen filter.
2116 */
2117 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
2118 #define PNG_HISHIFT 10
2119 #define PNG_LOMASK ((png_uint_32)0xffffL)
2120 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2121 void /* PRIVATE */
2122 png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2123 {
2124 png_bytep best_row;
2125 #ifndef PNG_NO_WRITE_FILTER
2126 png_bytep prev_row, row_buf;
2127 png_uint_32 mins, bpp;
2128 png_byte filter_to_do = png_ptr->do_filter;
2129 png_uint_32 row_bytes = row_info->rowbytes;
2130 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2131 int num_p_filters = (int)png_ptr->num_prev_filters;
2132 #endif
2133
2134 png_debug(1, "in png_write_find_filter");
2135
2136
2137 png_debug(1, "in png_write_find_filter");
2138 /* Find out how many bytes offset each pixel is */
2139 bpp = (row_info->pixel_depth + 7) >> 3;
2140
2141 prev_row = png_ptr->prev_row;
2142 #endif
2143 best_row = png_ptr->row_buf;
2144 #ifndef PNG_NO_WRITE_FILTER
2145 row_buf = best_row;
2146 mins = PNG_MAXSUM;
2147
2148 /* The prediction method we use is to find which method provides the
2149 * smallest value when summing the absolute values of the distances
2150 * from zero, using anything >= 128 as negative numbers. This is known
2151 * as the "minimum sum of absolute differences" heuristic. Other
2152 * heuristics are the "weighted minimum sum of absolute differences"
2153 * (experimental and can in theory improve compression), and the "zlib
2154 * predictive" method (not implemented yet), which does test compressions
2155 * of lines using different filter methods, and then chooses the
2156 * (series of) filter(s) that give minimum compressed data size (VERY
2157 * computationally expensive).
2158 *
2159 * GRR 980525: consider also
2160 * (1) minimum sum of absolute differences from running average (i.e.,
2161 * keep running sum of non-absolute differences & count of bytes)
2162 * [track dispersion, too? restart average if dispersion too large?]
2163 * (1b) minimum sum of absolute differences from sliding average, probably
2164 * with window size <= deflate window (usually 32K)
2165 * (2) minimum sum of squared differences from zero or running average
2166 * (i.e., ~ root-mean-square approach)
2167 */
2168
2169
2170 /* We don't need to test the 'no filter' case if this is the only filter
2171 * that has been chosen, as it doesn't actually do anything to the data.
2172 */
2173 if ((filter_to_do & PNG_FILTER_NONE) &&
2174 filter_to_do != PNG_FILTER_NONE)
2175 {
2176 png_bytep rp;
2177 png_uint_32 sum = 0;
2178 png_uint_32 i;
2179 int v;
2180
2181 for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2182 {
2183 v = *rp;
2184 sum += (v < 128) ? v : 256 - v;
2185 }
2186
2187 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2188 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2189 {
2190 png_uint_32 sumhi, sumlo;
2191 int j;
2192 sumlo = sum & PNG_LOMASK;
2193 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2194
2195 /* Reduce the sum if we match any of the previous rows */
2196 for (j = 0; j < num_p_filters; j++)
2197 {
2198 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2199 {
2200 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2201 PNG_WEIGHT_SHIFT;
2202 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2203 PNG_WEIGHT_SHIFT;
2204 }
2205 }
2206
2207 /* Factor in the cost of this filter (this is here for completeness,
2208 * but it makes no sense to have a "cost" for the NONE filter, as
2209 * it has the minimum possible computational cost - none).
2210 */
2211 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2212 PNG_COST_SHIFT;
2213 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2214 PNG_COST_SHIFT;
2215
2216 if (sumhi > PNG_HIMASK)
2217 sum = PNG_MAXSUM;
2218 else
2219 sum = (sumhi << PNG_HISHIFT) + sumlo;
2220 }
2221 #endif
2222 mins = sum;
2223 }
2224
2225 /* Sub filter */
2226 if (filter_to_do == PNG_FILTER_SUB)
2227 /* It's the only filter so no testing is needed */
2228 {
2229 png_bytep rp, lp, dp;
2230 png_uint_32 i;
2231 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2232 i++, rp++, dp++)
2233 {
2234 *dp = *rp;
2235 }
2236 for (lp = row_buf + 1; i < row_bytes;
2237 i++, rp++, lp++, dp++)
2238 {
2239 *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2240 }
2241 best_row = png_ptr->sub_row;
2242 }
2243
2244 else if (filter_to_do & PNG_FILTER_SUB)
2245 {
2246 png_bytep rp, dp, lp;
2247 png_uint_32 sum = 0, lmins = mins;
2248 png_uint_32 i;
2249 int v;
2250
2251 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2252 /* We temporarily increase the "minimum sum" by the factor we
2253 * would reduce the sum of this filter, so that we can do the
2254 * early exit comparison without scaling the sum each time.
2255 */
2256 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2257 {
2258 int j;
2259 png_uint_32 lmhi, lmlo;
2260 lmlo = lmins & PNG_LOMASK;
2261 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2262
2263 for (j = 0; j < num_p_filters; j++)
2264 {
2265 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2266 {
2267 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2268 PNG_WEIGHT_SHIFT;
2269 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2270 PNG_WEIGHT_SHIFT;
2271 }
2272 }
2273
2274 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2275 PNG_COST_SHIFT;
2276 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2277 PNG_COST_SHIFT;
2278
2279 if (lmhi > PNG_HIMASK)
2280 lmins = PNG_MAXSUM;
2281 else
2282 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2283 }
2284 #endif
2285
2286 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2287 i++, rp++, dp++)
2288 {
2289 v = *dp = *rp;
2290
2291 sum += (v < 128) ? v : 256 - v;
2292 }
2293 for (lp = row_buf + 1; i < row_bytes;
2294 i++, rp++, lp++, dp++)
2295 {
2296 v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2297
2298 sum += (v < 128) ? v : 256 - v;
2299
2300 if (sum > lmins) /* We are already worse, don't continue. */
2301 break;
2302 }
2303
2304 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2305 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2306 {
2307 int j;
2308 png_uint_32 sumhi, sumlo;
2309 sumlo = sum & PNG_LOMASK;
2310 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2311
2312 for (j = 0; j < num_p_filters; j++)
2313 {
2314 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2315 {
2316 sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2317 PNG_WEIGHT_SHIFT;
2318 sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2319 PNG_WEIGHT_SHIFT;
2320 }
2321 }
2322
2323 sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2324 PNG_COST_SHIFT;
2325 sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2326 PNG_COST_SHIFT;
2327
2328 if (sumhi > PNG_HIMASK)
2329 sum = PNG_MAXSUM;
2330 else
2331 sum = (sumhi << PNG_HISHIFT) + sumlo;
2332 }
2333 #endif
2334
2335 if (sum < mins)
2336 {
2337 mins = sum;
2338 best_row = png_ptr->sub_row;
2339 }
2340 }
2341
2342 /* Up filter */
2343 if (filter_to_do == PNG_FILTER_UP)
2344 {
2345 png_bytep rp, dp, pp;
2346 png_uint_32 i;
2347
2348 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2349 pp = prev_row + 1; i < row_bytes;
2350 i++, rp++, pp++, dp++)
2351 {
2352 *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2353 }
2354 best_row = png_ptr->up_row;
2355 }
2356
2357 else if (filter_to_do & PNG_FILTER_UP)
2358 {
2359 png_bytep rp, dp, pp;
2360 png_uint_32 sum = 0, lmins = mins;
2361 png_uint_32 i;
2362 int v;
2363
2364
2365 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2366 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2367 {
2368 int j;
2369 png_uint_32 lmhi, lmlo;
2370 lmlo = lmins & PNG_LOMASK;
2371 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2372
2373 for (j = 0; j < num_p_filters; j++)
2374 {
2375 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2376 {
2377 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2378 PNG_WEIGHT_SHIFT;
2379 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2380 PNG_WEIGHT_SHIFT;
2381 }
2382 }
2383
2384 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2385 PNG_COST_SHIFT;
2386 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2387 PNG_COST_SHIFT;
2388
2389 if (lmhi > PNG_HIMASK)
2390 lmins = PNG_MAXSUM;
2391 else
2392 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2393 }
2394 #endif
2395
2396 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2397 pp = prev_row + 1; i < row_bytes; i++)
2398 {
2399 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2400
2401 sum += (v < 128) ? v : 256 - v;
2402
2403 if (sum > lmins) /* We are already worse, don't continue. */
2404 break;
2405 }
2406
2407 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2408 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2409 {
2410 int j;
2411 png_uint_32 sumhi, sumlo;
2412 sumlo = sum & PNG_LOMASK;
2413 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2414
2415 for (j = 0; j < num_p_filters; j++)
2416 {
2417 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2418 {
2419 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2420 PNG_WEIGHT_SHIFT;
2421 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2422 PNG_WEIGHT_SHIFT;
2423 }
2424 }
2425
2426 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2427 PNG_COST_SHIFT;
2428 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2429 PNG_COST_SHIFT;
2430
2431 if (sumhi > PNG_HIMASK)
2432 sum = PNG_MAXSUM;
2433 else
2434 sum = (sumhi << PNG_HISHIFT) + sumlo;
2435 }
2436 #endif
2437
2438 if (sum < mins)
2439 {
2440 mins = sum;
2441 best_row = png_ptr->up_row;
2442 }
2443 }
2444
2445 /* Avg filter */
2446 if (filter_to_do == PNG_FILTER_AVG)
2447 {
2448 png_bytep rp, dp, pp, lp;
2449 png_uint_32 i;
2450 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2451 pp = prev_row + 1; i < bpp; i++)
2452 {
2453 *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2454 }
2455 for (lp = row_buf + 1; i < row_bytes; i++)
2456 {
2457 *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2458 & 0xff);
2459 }
2460 best_row = png_ptr->avg_row;
2461 }
2462
2463 else if (filter_to_do & PNG_FILTER_AVG)
2464 {
2465 png_bytep rp, dp, pp, lp;
2466 png_uint_32 sum = 0, lmins = mins;
2467 png_uint_32 i;
2468 int v;
2469
2470 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2471 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2472 {
2473 int j;
2474 png_uint_32 lmhi, lmlo;
2475 lmlo = lmins & PNG_LOMASK;
2476 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2477
2478 for (j = 0; j < num_p_filters; j++)
2479 {
2480 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2481 {
2482 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2483 PNG_WEIGHT_SHIFT;
2484 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2485 PNG_WEIGHT_SHIFT;
2486 }
2487 }
2488
2489 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2490 PNG_COST_SHIFT;
2491 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2492 PNG_COST_SHIFT;
2493
2494 if (lmhi > PNG_HIMASK)
2495 lmins = PNG_MAXSUM;
2496 else
2497 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2498 }
2499 #endif
2500
2501 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2502 pp = prev_row + 1; i < bpp; i++)
2503 {
2504 v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2505
2506 sum += (v < 128) ? v : 256 - v;
2507 }
2508 for (lp = row_buf + 1; i < row_bytes; i++)
2509 {
2510 v = *dp++ =
2511 (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2512
2513 sum += (v < 128) ? v : 256 - v;
2514
2515 if (sum > lmins) /* We are already worse, don't continue. */
2516 break;
2517 }
2518
2519 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2520 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2521 {
2522 int j;
2523 png_uint_32 sumhi, sumlo;
2524 sumlo = sum & PNG_LOMASK;
2525 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2526
2527 for (j = 0; j < num_p_filters; j++)
2528 {
2529 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2530 {
2531 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2532 PNG_WEIGHT_SHIFT;
2533 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2534 PNG_WEIGHT_SHIFT;
2535 }
2536 }
2537
2538 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2539 PNG_COST_SHIFT;
2540 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2541 PNG_COST_SHIFT;
2542
2543 if (sumhi > PNG_HIMASK)
2544 sum = PNG_MAXSUM;
2545 else
2546 sum = (sumhi << PNG_HISHIFT) + sumlo;
2547 }
2548 #endif
2549
2550 if (sum < mins)
2551 {
2552 mins = sum;
2553 best_row = png_ptr->avg_row;
2554 }
2555 }
2556
2557 /* Paeth filter */
2558 if (filter_to_do == PNG_FILTER_PAETH)
2559 {
2560 png_bytep rp, dp, pp, cp, lp;
2561 png_uint_32 i;
2562 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2563 pp = prev_row + 1; i < bpp; i++)
2564 {
2565 *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2566 }
2567
2568 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2569 {
2570 int a, b, c, pa, pb, pc, p;
2571
2572 b = *pp++;
2573 c = *cp++;
2574 a = *lp++;
2575
2576 p = b - c;
2577 pc = a - c;
2578
2579 #ifdef PNG_USE_ABS
2580 pa = abs(p);
2581 pb = abs(pc);
2582 pc = abs(p + pc);
2583 #else
2584 pa = p < 0 ? -p : p;
2585 pb = pc < 0 ? -pc : pc;
2586 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2587 #endif
2588
2589 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2590
2591 *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2592 }
2593 best_row = png_ptr->paeth_row;
2594 }
2595
2596 else if (filter_to_do & PNG_FILTER_PAETH)
2597 {
2598 png_bytep rp, dp, pp, cp, lp;
2599 png_uint_32 sum = 0, lmins = mins;
2600 png_uint_32 i;
2601 int v;
2602
2603 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2604 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2605 {
2606 int j;
2607 png_uint_32 lmhi, lmlo;
2608 lmlo = lmins & PNG_LOMASK;
2609 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2610
2611 for (j = 0; j < num_p_filters; j++)
2612 {
2613 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2614 {
2615 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2616 PNG_WEIGHT_SHIFT;
2617 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2618 PNG_WEIGHT_SHIFT;
2619 }
2620 }
2621
2622 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2623 PNG_COST_SHIFT;
2624 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2625 PNG_COST_SHIFT;
2626
2627 if (lmhi > PNG_HIMASK)
2628 lmins = PNG_MAXSUM;
2629 else
2630 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2631 }
2632 #endif
2633
2634 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2635 pp = prev_row + 1; i < bpp; i++)
2636 {
2637 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2638
2639 sum += (v < 128) ? v : 256 - v;
2640 }
2641
2642 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2643 {
2644 int a, b, c, pa, pb, pc, p;
2645
2646 b = *pp++;
2647 c = *cp++;
2648 a = *lp++;
2649
2650 #ifndef PNG_SLOW_PAETH
2651 p = b - c;
2652 pc = a - c;
2653 #ifdef PNG_USE_ABS
2654 pa = abs(p);
2655 pb = abs(pc);
2656 pc = abs(p + pc);
2657 #else
2658 pa = p < 0 ? -p : p;
2659 pb = pc < 0 ? -pc : pc;
2660 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2661 #endif
2662 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2663 #else /* PNG_SLOW_PAETH */
2664 p = a + b - c;
2665 pa = abs(p - a);
2666 pb = abs(p - b);
2667 pc = abs(p - c);
2668 if (pa <= pb && pa <= pc)
2669 p = a;
2670 else if (pb <= pc)
2671 p = b;
2672 else
2673 p = c;
2674 #endif /* PNG_SLOW_PAETH */
2675
2676 v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2677
2678 sum += (v < 128) ? v : 256 - v;
2679
2680 if (sum > lmins) /* We are already worse, don't continue. */
2681 break;
2682 }
2683
2684 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2685 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2686 {
2687 int j;
2688 png_uint_32 sumhi, sumlo;
2689 sumlo = sum & PNG_LOMASK;
2690 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2691
2692 for (j = 0; j < num_p_filters; j++)
2693 {
2694 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2695 {
2696 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2697 PNG_WEIGHT_SHIFT;
2698 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2699 PNG_WEIGHT_SHIFT;
2700 }
2701 }
2702
2703 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2704 PNG_COST_SHIFT;
2705 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2706 PNG_COST_SHIFT;
2707
2708 if (sumhi > PNG_HIMASK)
2709 sum = PNG_MAXSUM;
2710 else
2711 sum = (sumhi << PNG_HISHIFT) + sumlo;
2712 }
2713 #endif
2714
2715 if (sum < mins)
2716 {
2717 best_row = png_ptr->paeth_row;
2718 }
2719 }
2720 #endif /* PNG_NO_WRITE_FILTER */
2721 /* Do the actual writing of the filtered row data from the chosen filter. */
2722
2723 png_write_filtered_row(png_ptr, best_row);
2724
2725 #ifndef PNG_NO_WRITE_FILTER
2726 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2727 /* Save the type of filter we picked this time for future calculations */
2728 if (png_ptr->num_prev_filters > 0)
2729 {
2730 int j;
2731 for (j = 1; j < num_p_filters; j++)
2732 {
2733 png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
2734 }
2735 png_ptr->prev_filters[j] = best_row[0];
2736 }
2737 #endif
2738 #endif /* PNG_NO_WRITE_FILTER */
2739 }
2740
2741
2742 /* Do the actual writing of a previously filtered row. */
2743 void /* PRIVATE */
2744 png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2745 {
2746 png_debug(1, "in png_write_filtered_row");
2747 png_debug1(2, "filter = %d", filtered_row[0]);
2748 /* Set up the zlib input buffer */
2749
2750 png_ptr->zstream.next_in = filtered_row;
2751 png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
2752 /* Repeat until we have compressed all the data */
2753 do
2754 {
2755 int ret; /* Return of zlib */
2756
2757 /* Compress the data */
2758 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2759 /* Check for compression errors */
2760 if (ret != Z_OK)
2761 {
2762 if (png_ptr->zstream.msg != NULL)
2763 png_error(png_ptr, png_ptr->zstream.msg);
2764 else
2765 png_error(png_ptr, "zlib error");
2766 }
2767
2768 /* See if it is time to write another IDAT */
2769 if (!(png_ptr->zstream.avail_out))
2770 {
2771 /* Write the IDAT and reset the zlib output buffer */
2772 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2773 png_ptr->zstream.next_out = png_ptr->zbuf;
2774 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2775 }
2776 /* Repeat until all data has been compressed */
2777 } while (png_ptr->zstream.avail_in);
2778
2779 /* Swap the current and previous rows */
2780 if (png_ptr->prev_row != NULL)
2781 {
2782 png_bytep tptr;
2783
2784 tptr = png_ptr->prev_row;
2785 png_ptr->prev_row = png_ptr->row_buf;
2786 png_ptr->row_buf = tptr;
2787 }
2788
2789 /* Finish row - updates counters and flushes zlib if last row */
2790 png_write_finish_row(png_ptr);
2791
2792 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2793 png_ptr->flush_rows++;
2794
2795 if (png_ptr->flush_dist > 0 &&
2796 png_ptr->flush_rows >= png_ptr->flush_dist)
2797 {
2798 png_write_flush(png_ptr);
2799 }
2800 #endif
2801 }
2802 #endif /* PNG_WRITE_SUPPORTED */

  ViewVC Help
Powered by ViewVC 1.1.22