2
/* pngwutil.c - utilities to write a PNG file
4
* Last changed in libpng 1.4.1 [February 25, 2010]
5
* Copyright (c) 1998-2010 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.)
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
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* and license in png.h
14
#define PNG_NO_PEDANTIC_WARNINGS
16
#ifdef PNG_WRITE_SUPPORTED
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/* 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.
24
png_save_uint_32(png_bytep buf, png_uint_32 i)
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buf[0] = (png_byte)((i >> 24) & 0xff);
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buf[1] = (png_byte)((i >> 16) & 0xff);
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buf[2] = (png_byte)((i >> 8) & 0xff);
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buf[3] = (png_byte)(i & 0xff);
32
#ifdef PNG_SAVE_INT_32_SUPPORTED
33
/* The png_save_int_32 function assumes integers are stored in two's
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* complement format. If this isn't the case, then this routine needs to
35
* be modified to write data in two's complement format.
38
png_save_int_32(png_bytep buf, png_int_32 i)
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buf[0] = (png_byte)((i >> 24) & 0xff);
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buf[1] = (png_byte)((i >> 16) & 0xff);
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buf[2] = (png_byte)((i >> 8) & 0xff);
43
buf[3] = (png_byte)(i & 0xff);
47
/* Place a 16-bit number into a buffer in PNG byte order.
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* The parameter is declared unsigned int, not png_uint_16,
49
* just to avoid potential problems on pre-ANSI C compilers.
52
png_save_uint_16(png_bytep buf, unsigned int i)
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buf[0] = (png_byte)((i >> 8) & 0xff);
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buf[1] = (png_byte)(i & 0xff);
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/* Simple function to write the signature. If we have already written
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* the magic bytes of the signature, or more likely, the PNG stream is
60
* being embedded into another stream and doesn't need its own signature,
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* we should call png_set_sig_bytes() to tell libpng how many of the
62
* bytes have already been written.
65
png_write_sig(png_structp png_ptr)
67
png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
69
#ifdef PNG_IO_STATE_SUPPORTED
70
/* Inform the I/O callback that the signature is being written */
71
png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
74
/* Write the rest of the 8 byte signature */
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png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
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(png_size_t)(8 - png_ptr->sig_bytes));
77
if (png_ptr->sig_bytes < 3)
78
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
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/* Write a PNG chunk all at once. The type is an array of ASCII characters
82
* representing the chunk name. The array must be at least 4 bytes in
83
* length, and does not need to be null terminated. To be safe, pass the
84
* pre-defined chunk names here, and if you need a new one, define it
85
* where the others are defined. The length is the length of the data.
86
* All the data must be present. If that is not possible, use the
87
* png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
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png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
92
png_bytep data, png_size_t length)
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png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
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png_write_chunk_data(png_ptr, data, (png_size_t)length);
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png_write_chunk_end(png_ptr);
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/* Write the start of a PNG chunk. The type is the chunk type.
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* The total_length is the sum of the lengths of all the data you will be
103
* passing in png_write_chunk_data().
106
png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
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png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
112
(unsigned long)length);
117
#ifdef PNG_IO_STATE_SUPPORTED
118
/* Inform the I/O callback that the chunk header is being written.
119
* PNG_IO_CHUNK_HDR requires a single I/O call.
121
png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
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/* Write the length and the chunk name */
125
png_save_uint_32(buf, length);
126
png_memcpy(buf + 4, chunk_name, 4);
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png_write_data(png_ptr, buf, (png_size_t)8);
128
/* Put the chunk name into png_ptr->chunk_name */
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png_memcpy(png_ptr->chunk_name, chunk_name, 4);
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/* Reset the crc and run it over the chunk name */
131
png_reset_crc(png_ptr);
132
png_calculate_crc(png_ptr, chunk_name, 4);
134
#ifdef PNG_IO_STATE_SUPPORTED
135
/* Inform the I/O callback that chunk data will (possibly) be written.
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* PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
138
png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
142
/* Write the data of a PNG chunk started with png_write_chunk_start().
143
* Note that multiple calls to this function are allowed, and that the
144
* sum of the lengths from these calls *must* add up to the total_length
145
* given to png_write_chunk_start().
148
png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
150
/* Write the data, and run the CRC over it */
153
if (data != NULL && length > 0)
155
png_write_data(png_ptr, data, length);
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/* Update the CRC after writing the data,
157
* in case that the user I/O routine alters it.
159
png_calculate_crc(png_ptr, data, length);
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/* Finish a chunk started with png_write_chunk_start(). */
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png_write_chunk_end(png_structp png_ptr)
169
if (png_ptr == NULL) return;
171
#ifdef PNG_IO_STATE_SUPPORTED
172
/* Inform the I/O callback that the chunk CRC is being written.
173
* PNG_IO_CHUNK_CRC requires a single I/O function call.
175
png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
178
/* Write the crc in a single operation */
179
png_save_uint_32(buf, png_ptr->crc);
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png_write_data(png_ptr, buf, (png_size_t)4);
184
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
185
/* This pair of functions encapsulates the operation of (a) compressing a
186
* text string, and (b) issuing it later as a series of chunk data writes.
187
* The compression_state structure is shared context for these functions
188
* set up by the caller in order to make the whole mess thread-safe.
193
char *input; /* The uncompressed input data */
194
int input_len; /* Its length */
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int num_output_ptr; /* Number of output pointers used */
196
int max_output_ptr; /* Size of output_ptr */
197
png_charpp output_ptr; /* Array of pointers to output */
200
/* Compress given text into storage in the png_ptr structure */
201
static int /* PRIVATE */
202
png_text_compress(png_structp png_ptr,
203
png_charp text, png_size_t text_len, int compression,
204
compression_state *comp)
208
comp->num_output_ptr = 0;
209
comp->max_output_ptr = 0;
210
comp->output_ptr = NULL;
214
/* We may just want to pass the text right through */
215
if (compression == PNG_TEXT_COMPRESSION_NONE)
218
comp->input_len = text_len;
219
return((int)text_len);
222
if (compression >= PNG_TEXT_COMPRESSION_LAST)
224
#ifdef PNG_STDIO_SUPPORTED
226
png_snprintf(msg, 50, "Unknown compression type %d", compression);
227
png_warning(png_ptr, msg);
229
png_warning(png_ptr, "Unknown compression type");
233
/* We can't write the chunk until we find out how much data we have,
234
* which means we need to run the compressor first and save the
235
* output. This shouldn't be a problem, as the vast majority of
236
* comments should be reasonable, but we will set up an array of
237
* malloc'd pointers to be sure.
239
* If we knew the application was well behaved, we could simplify this
240
* greatly by assuming we can always malloc an output buffer large
241
* enough to hold the compressed text ((1001 * text_len / 1000) + 12)
242
* and malloc this directly. The only time this would be a bad idea is
243
* if we can't malloc more than 64K and we have 64K of random input
244
* data, or if the input string is incredibly large (although this
245
* wouldn't cause a failure, just a slowdown due to swapping).
248
/* Set up the compression buffers */
249
png_ptr->zstream.avail_in = (uInt)text_len;
250
png_ptr->zstream.next_in = (Bytef *)text;
251
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
252
png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
254
/* This is the same compression loop as in png_write_row() */
257
/* Compress the data */
258
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
262
if (png_ptr->zstream.msg != NULL)
263
png_error(png_ptr, png_ptr->zstream.msg);
265
png_error(png_ptr, "zlib error");
267
/* Check to see if we need more room */
268
if (!(png_ptr->zstream.avail_out))
270
/* Make sure the output array has room */
271
if (comp->num_output_ptr >= comp->max_output_ptr)
275
old_max = comp->max_output_ptr;
276
comp->max_output_ptr = comp->num_output_ptr + 4;
277
if (comp->output_ptr != NULL)
281
old_ptr = comp->output_ptr;
282
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
284
(comp->max_output_ptr * png_sizeof(png_charpp)));
285
png_memcpy(comp->output_ptr, old_ptr, old_max
286
* png_sizeof(png_charp));
287
png_free(png_ptr, old_ptr);
290
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
292
(comp->max_output_ptr * png_sizeof(png_charp)));
296
comp->output_ptr[comp->num_output_ptr] =
297
(png_charp)png_malloc(png_ptr,
298
(png_alloc_size_t)png_ptr->zbuf_size);
299
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
301
comp->num_output_ptr++;
303
/* and reset the buffer */
304
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
305
png_ptr->zstream.next_out = png_ptr->zbuf;
307
/* Continue until we don't have any more to compress */
308
} while (png_ptr->zstream.avail_in);
310
/* Finish the compression */
313
/* Tell zlib we are finished */
314
ret = deflate(&png_ptr->zstream, Z_FINISH);
318
/* Check to see if we need more room */
319
if (!(png_ptr->zstream.avail_out))
321
/* Check to make sure our output array has room */
322
if (comp->num_output_ptr >= comp->max_output_ptr)
326
old_max = comp->max_output_ptr;
327
comp->max_output_ptr = comp->num_output_ptr + 4;
328
if (comp->output_ptr != NULL)
332
old_ptr = comp->output_ptr;
333
/* This could be optimized to realloc() */
334
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_alloc_size_t)(comp->max_output_ptr *
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png_sizeof(png_charp)));
337
png_memcpy(comp->output_ptr, old_ptr,
338
old_max * png_sizeof(png_charp));
339
png_free(png_ptr, old_ptr);
342
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_alloc_size_t)(comp->max_output_ptr *
344
png_sizeof(png_charp)));
348
comp->output_ptr[comp->num_output_ptr] =
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(png_charp)png_malloc(png_ptr,
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(png_alloc_size_t)png_ptr->zbuf_size);
351
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
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comp->num_output_ptr++;
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/* and reset the buffer pointers */
356
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
357
png_ptr->zstream.next_out = png_ptr->zbuf;
360
else if (ret != Z_STREAM_END)
362
/* We got an error */
363
if (png_ptr->zstream.msg != NULL)
364
png_error(png_ptr, png_ptr->zstream.msg);
366
png_error(png_ptr, "zlib error");
368
} while (ret != Z_STREAM_END);
370
/* Text length is number of buffers plus last buffer */
371
text_len = png_ptr->zbuf_size * comp->num_output_ptr;
372
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
373
text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
375
return((int)text_len);
378
/* Ship the compressed text out via chunk writes */
379
static void /* PRIVATE */
380
png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
384
/* Handle the no-compression case */
387
png_write_chunk_data(png_ptr, (png_bytep)comp->input,
388
(png_size_t)comp->input_len);
392
/* Write saved output buffers, if any */
393
for (i = 0; i < comp->num_output_ptr; i++)
395
png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
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(png_size_t)png_ptr->zbuf_size);
397
png_free(png_ptr, comp->output_ptr[i]);
399
if (comp->max_output_ptr != 0)
400
png_free(png_ptr, comp->output_ptr);
401
/* Write anything left in zbuf */
402
if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
403
png_write_chunk_data(png_ptr, png_ptr->zbuf,
404
(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
406
/* Reset zlib for another zTXt/iTXt or image data */
407
deflateReset(&png_ptr->zstream);
408
png_ptr->zstream.data_type = Z_BINARY;
412
/* Write the IHDR chunk, and update the png_struct with the necessary
413
* information. Note that the rest of this code depends upon this
414
* information being correct.
417
png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
418
int bit_depth, int color_type, int compression_type, int filter_type,
424
png_byte buf[13]; /* Buffer to store the IHDR info */
426
png_debug(1, "in png_write_IHDR");
428
/* Check that we have valid input data from the application info */
431
case PNG_COLOR_TYPE_GRAY:
438
case 16: png_ptr->channels = 1; break;
439
default: png_error(png_ptr,
440
"Invalid bit depth for grayscale image");
443
case PNG_COLOR_TYPE_RGB:
444
if (bit_depth != 8 && bit_depth != 16)
445
png_error(png_ptr, "Invalid bit depth for RGB image");
446
png_ptr->channels = 3;
448
case PNG_COLOR_TYPE_PALETTE:
454
case 8: png_ptr->channels = 1; break;
455
default: png_error(png_ptr, "Invalid bit depth for paletted image");
458
case PNG_COLOR_TYPE_GRAY_ALPHA:
459
if (bit_depth != 8 && bit_depth != 16)
460
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
461
png_ptr->channels = 2;
463
case PNG_COLOR_TYPE_RGB_ALPHA:
464
if (bit_depth != 8 && bit_depth != 16)
465
png_error(png_ptr, "Invalid bit depth for RGBA image");
466
png_ptr->channels = 4;
469
png_error(png_ptr, "Invalid image color type specified");
472
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
474
png_warning(png_ptr, "Invalid compression type specified");
475
compression_type = PNG_COMPRESSION_TYPE_BASE;
478
/* Write filter_method 64 (intrapixel differencing) only if
479
* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
480
* 2. Libpng did not write a PNG signature (this filter_method is only
481
* used in PNG datastreams that are embedded in MNG datastreams) and
482
* 3. The application called png_permit_mng_features with a mask that
483
* included PNG_FLAG_MNG_FILTER_64 and
484
* 4. The filter_method is 64 and
485
* 5. The color_type is RGB or RGBA
488
#ifdef PNG_MNG_FEATURES_SUPPORTED
489
!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
490
((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
491
(color_type == PNG_COLOR_TYPE_RGB ||
492
color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
493
(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
495
filter_type != PNG_FILTER_TYPE_BASE)
497
png_warning(png_ptr, "Invalid filter type specified");
498
filter_type = PNG_FILTER_TYPE_BASE;
501
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
502
if (interlace_type != PNG_INTERLACE_NONE &&
503
interlace_type != PNG_INTERLACE_ADAM7)
505
png_warning(png_ptr, "Invalid interlace type specified");
506
interlace_type = PNG_INTERLACE_ADAM7;
509
interlace_type=PNG_INTERLACE_NONE;
512
/* Save the relevent information */
513
png_ptr->bit_depth = (png_byte)bit_depth;
514
png_ptr->color_type = (png_byte)color_type;
515
png_ptr->interlaced = (png_byte)interlace_type;
516
#ifdef PNG_MNG_FEATURES_SUPPORTED
517
png_ptr->filter_type = (png_byte)filter_type;
519
png_ptr->compression_type = (png_byte)compression_type;
520
png_ptr->width = width;
521
png_ptr->height = height;
523
png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
524
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
525
/* Set the usr info, so any transformations can modify it */
526
png_ptr->usr_width = png_ptr->width;
527
png_ptr->usr_bit_depth = png_ptr->bit_depth;
528
png_ptr->usr_channels = png_ptr->channels;
530
/* Pack the header information into the buffer */
531
png_save_uint_32(buf, width);
532
png_save_uint_32(buf + 4, height);
533
buf[8] = (png_byte)bit_depth;
534
buf[9] = (png_byte)color_type;
535
buf[10] = (png_byte)compression_type;
536
buf[11] = (png_byte)filter_type;
537
buf[12] = (png_byte)interlace_type;
539
/* Write the chunk */
540
png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
542
/* Initialize zlib with PNG info */
543
png_ptr->zstream.zalloc = png_zalloc;
544
png_ptr->zstream.zfree = png_zfree;
545
png_ptr->zstream.opaque = (voidpf)png_ptr;
546
if (!(png_ptr->do_filter))
548
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
549
png_ptr->bit_depth < 8)
550
png_ptr->do_filter = PNG_FILTER_NONE;
552
png_ptr->do_filter = PNG_ALL_FILTERS;
554
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
556
if (png_ptr->do_filter != PNG_FILTER_NONE)
557
png_ptr->zlib_strategy = Z_FILTERED;
559
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
561
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
562
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
563
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
564
png_ptr->zlib_mem_level = 8;
565
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
566
png_ptr->zlib_window_bits = 15;
567
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
568
png_ptr->zlib_method = 8;
569
ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
570
png_ptr->zlib_method, png_ptr->zlib_window_bits,
571
png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
574
if (ret == Z_VERSION_ERROR) png_error(png_ptr,
575
"zlib failed to initialize compressor -- version error");
576
if (ret == Z_STREAM_ERROR) png_error(png_ptr,
577
"zlib failed to initialize compressor -- stream error");
578
if (ret == Z_MEM_ERROR) png_error(png_ptr,
579
"zlib failed to initialize compressor -- mem error");
580
png_error(png_ptr, "zlib failed to initialize compressor");
582
png_ptr->zstream.next_out = png_ptr->zbuf;
583
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
584
/* libpng is not interested in zstream.data_type */
585
/* Set it to a predefined value, to avoid its evaluation inside zlib */
586
png_ptr->zstream.data_type = Z_BINARY;
588
png_ptr->mode = PNG_HAVE_IHDR;
591
/* Write the palette. We are careful not to trust png_color to be in the
592
* correct order for PNG, so people can redefine it to any convenient
596
png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
603
png_debug(1, "in png_write_PLTE");
606
#ifdef PNG_MNG_FEATURES_SUPPORTED
607
!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
609
num_pal == 0) || num_pal > 256)
611
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
613
png_error(png_ptr, "Invalid number of colors in palette");
617
png_warning(png_ptr, "Invalid number of colors in palette");
622
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
625
"Ignoring request to write a PLTE chunk in grayscale PNG");
629
png_ptr->num_palette = (png_uint_16)num_pal;
630
png_debug1(3, "num_palette = %d", png_ptr->num_palette);
632
png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
633
(png_uint_32)(num_pal * 3));
634
#ifdef PNG_POINTER_INDEXING_SUPPORTED
635
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
637
buf[0] = pal_ptr->red;
638
buf[1] = pal_ptr->green;
639
buf[2] = pal_ptr->blue;
640
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
643
/* This is a little slower but some buggy compilers need to do this
647
for (i = 0; i < num_pal; i++)
649
buf[0] = pal_ptr[i].red;
650
buf[1] = pal_ptr[i].green;
651
buf[2] = pal_ptr[i].blue;
652
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
655
png_write_chunk_end(png_ptr);
656
png_ptr->mode |= PNG_HAVE_PLTE;
659
/* Write an IDAT chunk */
661
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
665
png_debug(1, "in png_write_IDAT");
667
/* Optimize the CMF field in the zlib stream. */
668
/* This hack of the zlib stream is compliant to the stream specification. */
669
if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
670
png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
672
unsigned int z_cmf = data[0]; /* zlib compression method and flags */
673
if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
675
/* Avoid memory underflows and multiplication overflows.
677
* The conditions below are practically always satisfied;
678
* however, they still must be checked.
681
png_ptr->height < 16384 && png_ptr->width < 16384)
683
png_uint_32 uncompressed_idat_size = png_ptr->height *
685
png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
686
unsigned int z_cinfo = z_cmf >> 4;
687
unsigned int half_z_window_size = 1 << (z_cinfo + 7);
688
while (uncompressed_idat_size <= half_z_window_size &&
689
half_z_window_size >= 256)
692
half_z_window_size >>= 1;
694
z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
695
if (data[0] != (png_byte)z_cmf)
697
data[0] = (png_byte)z_cmf;
699
data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
705
"Invalid zlib compression method or flags in IDAT");
708
png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
709
png_ptr->mode |= PNG_HAVE_IDAT;
712
/* Write an IEND chunk */
714
png_write_IEND(png_structp png_ptr)
718
png_debug(1, "in png_write_IEND");
720
png_write_chunk(png_ptr, (png_bytep)png_IEND, NULL,
722
png_ptr->mode |= PNG_HAVE_IEND;
725
#ifdef PNG_WRITE_gAMA_SUPPORTED
726
/* Write a gAMA chunk */
727
#ifdef PNG_FLOATING_POINT_SUPPORTED
729
png_write_gAMA(png_structp png_ptr, double file_gamma)
735
png_debug(1, "in png_write_gAMA");
737
/* file_gamma is saved in 1/100,000ths */
738
igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
739
png_save_uint_32(buf, igamma);
740
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
743
#ifdef PNG_FIXED_POINT_SUPPORTED
745
png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
750
png_debug(1, "in png_write_gAMA");
752
/* file_gamma is saved in 1/100,000ths */
753
png_save_uint_32(buf, (png_uint_32)file_gamma);
754
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
759
#ifdef PNG_WRITE_sRGB_SUPPORTED
760
/* Write a sRGB chunk */
762
png_write_sRGB(png_structp png_ptr, int srgb_intent)
767
png_debug(1, "in png_write_sRGB");
769
if (srgb_intent >= PNG_sRGB_INTENT_LAST)
771
"Invalid sRGB rendering intent specified");
772
buf[0]=(png_byte)srgb_intent;
773
png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
777
#ifdef PNG_WRITE_iCCP_SUPPORTED
778
/* Write an iCCP chunk */
780
png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
781
png_charp profile, int profile_len)
786
compression_state comp;
787
int embedded_profile_len = 0;
789
png_debug(1, "in png_write_iCCP");
791
comp.num_output_ptr = 0;
792
comp.max_output_ptr = 0;
793
comp.output_ptr = NULL;
797
if ((name_len = png_check_keyword(png_ptr, name,
801
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
802
png_warning(png_ptr, "Unknown compression type in iCCP chunk");
808
embedded_profile_len =
809
((*( (png_bytep)profile ))<<24) |
810
((*( (png_bytep)profile + 1))<<16) |
811
((*( (png_bytep)profile + 2))<< 8) |
812
((*( (png_bytep)profile + 3)) );
814
if (embedded_profile_len < 0)
817
"Embedded profile length in iCCP chunk is negative");
818
png_free(png_ptr, new_name);
822
if (profile_len < embedded_profile_len)
825
"Embedded profile length too large in iCCP chunk");
826
png_free(png_ptr, new_name);
830
if (profile_len > embedded_profile_len)
833
"Truncating profile to actual length in iCCP chunk");
834
profile_len = embedded_profile_len;
838
profile_len = png_text_compress(png_ptr, profile,
839
(png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
841
/* Make sure we include the NULL after the name and the compression type */
842
png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
843
(png_uint_32)(name_len + profile_len + 2));
844
new_name[name_len + 1] = 0x00;
845
png_write_chunk_data(png_ptr, (png_bytep)new_name,
846
(png_size_t)(name_len + 2));
849
png_write_compressed_data_out(png_ptr, &comp);
851
png_write_chunk_end(png_ptr);
852
png_free(png_ptr, new_name);
856
#ifdef PNG_WRITE_sPLT_SUPPORTED
857
/* Write a sPLT chunk */
859
png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
864
png_byte entrybuf[10];
865
png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
866
png_size_t palette_size = entry_size * spalette->nentries;
868
#ifndef PNG_POINTER_INDEXING_SUPPORTED
872
png_debug(1, "in png_write_sPLT");
874
if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
877
/* Make sure we include the NULL after the name */
878
png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
879
(png_uint_32)(name_len + 2 + palette_size));
880
png_write_chunk_data(png_ptr, (png_bytep)new_name,
881
(png_size_t)(name_len + 1));
882
png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
884
/* Loop through each palette entry, writing appropriately */
885
#ifdef PNG_POINTER_INDEXING_SUPPORTED
886
for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
888
if (spalette->depth == 8)
890
entrybuf[0] = (png_byte)ep->red;
891
entrybuf[1] = (png_byte)ep->green;
892
entrybuf[2] = (png_byte)ep->blue;
893
entrybuf[3] = (png_byte)ep->alpha;
894
png_save_uint_16(entrybuf + 4, ep->frequency);
898
png_save_uint_16(entrybuf + 0, ep->red);
899
png_save_uint_16(entrybuf + 2, ep->green);
900
png_save_uint_16(entrybuf + 4, ep->blue);
901
png_save_uint_16(entrybuf + 6, ep->alpha);
902
png_save_uint_16(entrybuf + 8, ep->frequency);
904
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
907
ep=spalette->entries;
908
for (i=0; i>spalette->nentries; i++)
910
if (spalette->depth == 8)
912
entrybuf[0] = (png_byte)ep[i].red;
913
entrybuf[1] = (png_byte)ep[i].green;
914
entrybuf[2] = (png_byte)ep[i].blue;
915
entrybuf[3] = (png_byte)ep[i].alpha;
916
png_save_uint_16(entrybuf + 4, ep[i].frequency);
920
png_save_uint_16(entrybuf + 0, ep[i].red);
921
png_save_uint_16(entrybuf + 2, ep[i].green);
922
png_save_uint_16(entrybuf + 4, ep[i].blue);
923
png_save_uint_16(entrybuf + 6, ep[i].alpha);
924
png_save_uint_16(entrybuf + 8, ep[i].frequency);
926
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
930
png_write_chunk_end(png_ptr);
931
png_free(png_ptr, new_name);
935
#ifdef PNG_WRITE_sBIT_SUPPORTED
936
/* Write the sBIT chunk */
938
png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
944
png_debug(1, "in png_write_sBIT");
946
/* Make sure we don't depend upon the order of PNG_COLOR_8 */
947
if (color_type & PNG_COLOR_MASK_COLOR)
951
maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
952
png_ptr->usr_bit_depth);
953
if (sbit->red == 0 || sbit->red > maxbits ||
954
sbit->green == 0 || sbit->green > maxbits ||
955
sbit->blue == 0 || sbit->blue > maxbits)
957
png_warning(png_ptr, "Invalid sBIT depth specified");
961
buf[1] = sbit->green;
967
if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
969
png_warning(png_ptr, "Invalid sBIT depth specified");
976
if (color_type & PNG_COLOR_MASK_ALPHA)
978
if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
980
png_warning(png_ptr, "Invalid sBIT depth specified");
983
buf[size++] = sbit->alpha;
986
png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
990
#ifdef PNG_WRITE_cHRM_SUPPORTED
991
/* Write the cHRM chunk */
992
#ifdef PNG_FLOATING_POINT_SUPPORTED
994
png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
995
double red_x, double red_y, double green_x, double green_y,
996
double blue_x, double blue_y)
1001
png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
1002
int_green_x, int_green_y, int_blue_x, int_blue_y;
1004
png_debug(1, "in png_write_cHRM");
1006
int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
1007
int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
1008
int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5);
1009
int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5);
1010
int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
1011
int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
1012
int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5);
1013
int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5);
1015
#ifdef PNG_CHECK_cHRM_SUPPORTED
1016
if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
1017
int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
1020
/* Each value is saved in 1/100,000ths */
1022
png_save_uint_32(buf, int_white_x);
1023
png_save_uint_32(buf + 4, int_white_y);
1025
png_save_uint_32(buf + 8, int_red_x);
1026
png_save_uint_32(buf + 12, int_red_y);
1028
png_save_uint_32(buf + 16, int_green_x);
1029
png_save_uint_32(buf + 20, int_green_y);
1031
png_save_uint_32(buf + 24, int_blue_x);
1032
png_save_uint_32(buf + 28, int_blue_y);
1034
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1038
#ifdef PNG_FIXED_POINT_SUPPORTED
1040
png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
1041
png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
1042
png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
1043
png_fixed_point blue_y)
1048
png_debug(1, "in png_write_cHRM");
1050
/* Each value is saved in 1/100,000ths */
1051
#ifdef PNG_CHECK_cHRM_SUPPORTED
1052
if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
1053
green_x, green_y, blue_x, blue_y))
1056
png_save_uint_32(buf, (png_uint_32)white_x);
1057
png_save_uint_32(buf + 4, (png_uint_32)white_y);
1059
png_save_uint_32(buf + 8, (png_uint_32)red_x);
1060
png_save_uint_32(buf + 12, (png_uint_32)red_y);
1062
png_save_uint_32(buf + 16, (png_uint_32)green_x);
1063
png_save_uint_32(buf + 20, (png_uint_32)green_y);
1065
png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1066
png_save_uint_32(buf + 28, (png_uint_32)blue_y);
1068
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1074
#ifdef PNG_WRITE_tRNS_SUPPORTED
1075
/* Write the tRNS chunk */
1077
png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
1078
int num_trans, int color_type)
1083
png_debug(1, "in png_write_tRNS");
1085
if (color_type == PNG_COLOR_TYPE_PALETTE)
1087
if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
1089
png_warning(png_ptr, "Invalid number of transparent colors specified");
1092
/* Write the chunk out as it is */
1093
png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans_alpha,
1094
(png_size_t)num_trans);
1096
else if (color_type == PNG_COLOR_TYPE_GRAY)
1098
/* One 16 bit value */
1099
if (tran->gray >= (1 << png_ptr->bit_depth))
1101
png_warning(png_ptr,
1102
"Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1105
png_save_uint_16(buf, tran->gray);
1106
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
1108
else if (color_type == PNG_COLOR_TYPE_RGB)
1110
/* Three 16 bit values */
1111
png_save_uint_16(buf, tran->red);
1112
png_save_uint_16(buf + 2, tran->green);
1113
png_save_uint_16(buf + 4, tran->blue);
1114
if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1116
png_warning(png_ptr,
1117
"Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1120
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
1124
png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1129
#ifdef PNG_WRITE_bKGD_SUPPORTED
1130
/* Write the background chunk */
1132
png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
1137
png_debug(1, "in png_write_bKGD");
1139
if (color_type == PNG_COLOR_TYPE_PALETTE)
1142
#ifdef PNG_MNG_FEATURES_SUPPORTED
1143
(png_ptr->num_palette ||
1144
(!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1146
back->index >= png_ptr->num_palette)
1148
png_warning(png_ptr, "Invalid background palette index");
1151
buf[0] = back->index;
1152
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
1154
else if (color_type & PNG_COLOR_MASK_COLOR)
1156
png_save_uint_16(buf, back->red);
1157
png_save_uint_16(buf + 2, back->green);
1158
png_save_uint_16(buf + 4, back->blue);
1159
if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1161
png_warning(png_ptr,
1162
"Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1165
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
1169
if (back->gray >= (1 << png_ptr->bit_depth))
1171
png_warning(png_ptr,
1172
"Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1175
png_save_uint_16(buf, back->gray);
1176
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
1181
#ifdef PNG_WRITE_hIST_SUPPORTED
1182
/* Write the histogram */
1184
png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
1190
png_debug(1, "in png_write_hIST");
1192
if (num_hist > (int)png_ptr->num_palette)
1194
png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
1195
png_ptr->num_palette);
1196
png_warning(png_ptr, "Invalid number of histogram entries specified");
1200
png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
1201
(png_uint_32)(num_hist * 2));
1202
for (i = 0; i < num_hist; i++)
1204
png_save_uint_16(buf, hist[i]);
1205
png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1207
png_write_chunk_end(png_ptr);
1211
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1212
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1213
/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1214
* and if invalid, correct the keyword rather than discarding the entire
1215
* chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1216
* length, forbids leading or trailing whitespace, multiple internal spaces,
1217
* and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1219
* The new_key is allocated to hold the corrected keyword and must be freed
1220
* by the calling routine. This avoids problems with trying to write to
1221
* static keywords without having to have duplicate copies of the strings.
1223
png_size_t /* PRIVATE */
1224
png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
1231
png_debug(1, "in png_check_keyword");
1235
if (key == NULL || (key_len = png_strlen(key)) == 0)
1237
png_warning(png_ptr, "zero length keyword");
1238
return ((png_size_t)0);
1241
png_debug1(2, "Keyword to be checked is '%s'", key);
1243
*new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1244
if (*new_key == NULL)
1246
png_warning(png_ptr, "Out of memory while procesing keyword");
1247
return ((png_size_t)0);
1250
/* Replace non-printing characters with a blank and print a warning */
1251
for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
1253
if ((png_byte)*kp < 0x20 ||
1254
((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
1256
#ifdef PNG_STDIO_SUPPORTED
1259
png_snprintf(msg, 40,
1260
"invalid keyword character 0x%02X", (png_byte)*kp);
1261
png_warning(png_ptr, msg);
1263
png_warning(png_ptr, "invalid character in keyword");
1274
/* Remove any trailing white space. */
1275
kp = *new_key + key_len - 1;
1278
png_warning(png_ptr, "trailing spaces removed from keyword");
1287
/* Remove any leading white space. */
1291
png_warning(png_ptr, "leading spaces removed from keyword");
1300
png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
1302
/* Remove multiple internal spaces. */
1303
for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1305
if (*kp == ' ' && kflag == 0)
1310
else if (*kp == ' ')
1323
png_warning(png_ptr, "extra interior spaces removed from keyword");
1327
png_free(png_ptr, *new_key);
1328
png_warning(png_ptr, "Zero length keyword");
1333
png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1334
(*new_key)[79] = '\0';
1342
#ifdef PNG_WRITE_tEXt_SUPPORTED
1343
/* Write a tEXt chunk */
1345
png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
1346
png_size_t text_len)
1352
png_debug(1, "in png_write_tEXt");
1354
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1357
if (text == NULL || *text == '\0')
1360
text_len = png_strlen(text);
1362
/* Make sure we include the 0 after the key */
1363
png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
1364
(png_uint_32)(key_len + text_len + 1));
1366
* We leave it to the application to meet PNG-1.0 requirements on the
1367
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1368
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1369
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1371
png_write_chunk_data(png_ptr, (png_bytep)new_key,
1372
(png_size_t)(key_len + 1));
1374
png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
1376
png_write_chunk_end(png_ptr);
1377
png_free(png_ptr, new_key);
1381
#ifdef PNG_WRITE_zTXt_SUPPORTED
1382
/* Write a compressed text chunk */
1384
png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
1385
png_size_t text_len, int compression)
1391
compression_state comp;
1393
png_debug(1, "in png_write_zTXt");
1395
comp.num_output_ptr = 0;
1396
comp.max_output_ptr = 0;
1397
comp.output_ptr = NULL;
1401
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1403
png_free(png_ptr, new_key);
1407
if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1409
png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1410
png_free(png_ptr, new_key);
1414
text_len = png_strlen(text);
1416
/* Compute the compressed data; do it now for the length */
1417
text_len = png_text_compress(png_ptr, text, text_len, compression,
1420
/* Write start of chunk */
1421
png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
1422
(png_uint_32)(key_len+text_len + 2));
1424
png_write_chunk_data(png_ptr, (png_bytep)new_key,
1425
(png_size_t)(key_len + 1));
1426
png_free(png_ptr, new_key);
1428
buf[0] = (png_byte)compression;
1429
/* Write compression */
1430
png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
1431
/* Write the compressed data */
1432
png_write_compressed_data_out(png_ptr, &comp);
1434
/* Close the chunk */
1435
png_write_chunk_end(png_ptr);
1439
#ifdef PNG_WRITE_iTXt_SUPPORTED
1440
/* Write an iTXt chunk */
1442
png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
1443
png_charp lang, png_charp lang_key, png_charp text)
1446
png_size_t lang_len, key_len, lang_key_len, text_len;
1448
png_charp new_key = NULL;
1450
compression_state comp;
1452
png_debug(1, "in png_write_iTXt");
1454
comp.num_output_ptr = 0;
1455
comp.max_output_ptr = 0;
1456
comp.output_ptr = NULL;
1459
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1462
if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
1464
png_warning(png_ptr, "Empty language field in iTXt chunk");
1469
if (lang_key == NULL)
1472
lang_key_len = png_strlen(lang_key);
1477
text_len = png_strlen(text);
1479
/* Compute the compressed data; do it now for the length */
1480
text_len = png_text_compress(png_ptr, text, text_len, compression-2,
1484
/* Make sure we include the compression flag, the compression byte,
1485
* and the NULs after the key, lang, and lang_key parts */
1487
png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
1489
5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1495
/* We leave it to the application to meet PNG-1.0 requirements on the
1496
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1497
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1498
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1500
png_write_chunk_data(png_ptr, (png_bytep)new_key,
1501
(png_size_t)(key_len + 1));
1503
/* Set the compression flag */
1504
if (compression == PNG_ITXT_COMPRESSION_NONE || \
1505
compression == PNG_TEXT_COMPRESSION_NONE)
1507
else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1509
/* Set the compression method */
1511
png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
1514
png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
1515
(png_size_t)(lang_len + 1));
1516
png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
1517
(png_size_t)(lang_key_len + 1));
1518
png_write_compressed_data_out(png_ptr, &comp);
1520
png_write_chunk_end(png_ptr);
1521
png_free(png_ptr, new_key);
1522
png_free(png_ptr, new_lang);
1526
#ifdef PNG_WRITE_oFFs_SUPPORTED
1527
/* Write the oFFs chunk */
1529
png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1535
png_debug(1, "in png_write_oFFs");
1537
if (unit_type >= PNG_OFFSET_LAST)
1538
png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1540
png_save_int_32(buf, x_offset);
1541
png_save_int_32(buf + 4, y_offset);
1542
buf[8] = (png_byte)unit_type;
1544
png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
1547
#ifdef PNG_WRITE_pCAL_SUPPORTED
1548
/* Write the pCAL chunk (described in the PNG extensions document) */
1550
png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1551
png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
1554
png_size_t purpose_len, units_len, total_len;
1555
png_uint_32p params_len;
1557
png_charp new_purpose;
1560
png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
1562
if (type >= PNG_EQUATION_LAST)
1563
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1565
purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1566
png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
1567
units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1568
png_debug1(3, "pCAL units length = %d", (int)units_len);
1569
total_len = purpose_len + units_len + 10;
1571
params_len = (png_uint_32p)png_malloc(png_ptr,
1572
(png_alloc_size_t)(nparams * png_sizeof(png_uint_32)));
1574
/* Find the length of each parameter, making sure we don't count the
1575
null terminator for the last parameter. */
1576
for (i = 0; i < nparams; i++)
1578
params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1579
png_debug2(3, "pCAL parameter %d length = %lu", i,
1580
(unsigned long) params_len[i]);
1581
total_len += (png_size_t)params_len[i];
1584
png_debug1(3, "pCAL total length = %d", (int)total_len);
1585
png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
1586
png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
1587
(png_size_t)purpose_len);
1588
png_save_int_32(buf, X0);
1589
png_save_int_32(buf + 4, X1);
1590
buf[8] = (png_byte)type;
1591
buf[9] = (png_byte)nparams;
1592
png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1593
png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
1595
png_free(png_ptr, new_purpose);
1597
for (i = 0; i < nparams; i++)
1599
png_write_chunk_data(png_ptr, (png_bytep)params[i],
1600
(png_size_t)params_len[i]);
1603
png_free(png_ptr, params_len);
1604
png_write_chunk_end(png_ptr);
1608
#ifdef PNG_WRITE_sCAL_SUPPORTED
1609
/* Write the sCAL chunk */
1610
#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
1612
png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
1616
png_size_t total_len;
1618
png_debug(1, "in png_write_sCAL");
1620
buf[0] = (char)unit;
1621
png_snprintf(buf + 1, 63, "%12.12e", width);
1622
total_len = 1 + png_strlen(buf + 1) + 1;
1623
png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
1624
total_len += png_strlen(buf + total_len);
1626
png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1627
png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
1630
#ifdef PNG_FIXED_POINT_SUPPORTED
1632
png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
1637
png_size_t wlen, hlen, total_len;
1639
png_debug(1, "in png_write_sCAL_s");
1641
wlen = png_strlen(width);
1642
hlen = png_strlen(height);
1643
total_len = wlen + hlen + 2;
1646
png_warning(png_ptr, "Can't write sCAL (buffer too small)");
1650
buf[0] = (png_byte)unit;
1651
png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
1652
png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
1654
png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
1655
png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
1661
#ifdef PNG_WRITE_pHYs_SUPPORTED
1662
/* Write the pHYs chunk */
1664
png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1665
png_uint_32 y_pixels_per_unit,
1671
png_debug(1, "in png_write_pHYs");
1673
if (unit_type >= PNG_RESOLUTION_LAST)
1674
png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1676
png_save_uint_32(buf, x_pixels_per_unit);
1677
png_save_uint_32(buf + 4, y_pixels_per_unit);
1678
buf[8] = (png_byte)unit_type;
1680
png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
1684
#ifdef PNG_WRITE_tIME_SUPPORTED
1685
/* Write the tIME chunk. Use either png_convert_from_struct_tm()
1686
* or png_convert_from_time_t(), or fill in the structure yourself.
1689
png_write_tIME(png_structp png_ptr, png_timep mod_time)
1694
png_debug(1, "in png_write_tIME");
1696
if (mod_time->month > 12 || mod_time->month < 1 ||
1697
mod_time->day > 31 || mod_time->day < 1 ||
1698
mod_time->hour > 23 || mod_time->second > 60)
1700
png_warning(png_ptr, "Invalid time specified for tIME chunk");
1704
png_save_uint_16(buf, mod_time->year);
1705
buf[2] = mod_time->month;
1706
buf[3] = mod_time->day;
1707
buf[4] = mod_time->hour;
1708
buf[5] = mod_time->minute;
1709
buf[6] = mod_time->second;
1711
png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
1715
/* Initializes the row writing capability of libpng */
1717
png_write_start_row(png_structp png_ptr)
1719
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1720
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1722
/* Start of interlace block */
1723
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1725
/* Offset to next interlace block */
1726
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1728
/* Start of interlace block in the y direction */
1729
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1731
/* Offset to next interlace block in the y direction */
1732
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1735
png_size_t buf_size;
1737
png_debug(1, "in png_write_start_row");
1739
buf_size = (png_size_t)(PNG_ROWBYTES(
1740
png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
1742
/* Set up row buffer */
1743
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
1744
(png_alloc_size_t)buf_size);
1745
png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1747
#ifdef PNG_WRITE_FILTER_SUPPORTED
1748
/* Set up filtering buffer, if using this filter */
1749
if (png_ptr->do_filter & PNG_FILTER_SUB)
1751
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1752
(png_alloc_size_t)(png_ptr->rowbytes + 1));
1753
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1756
/* We only need to keep the previous row if we are using one of these. */
1757
if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1759
/* Set up previous row buffer */
1760
png_ptr->prev_row = (png_bytep)png_calloc(png_ptr,
1761
(png_alloc_size_t)buf_size);
1763
if (png_ptr->do_filter & PNG_FILTER_UP)
1765
png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1766
(png_size_t)(png_ptr->rowbytes + 1));
1767
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1770
if (png_ptr->do_filter & PNG_FILTER_AVG)
1772
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1773
(png_alloc_size_t)(png_ptr->rowbytes + 1));
1774
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1777
if (png_ptr->do_filter & PNG_FILTER_PAETH)
1779
png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1780
(png_size_t)(png_ptr->rowbytes + 1));
1781
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1784
#endif /* PNG_WRITE_FILTER_SUPPORTED */
1786
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1787
/* If interlaced, we need to set up width and height of pass */
1788
if (png_ptr->interlaced)
1790
if (!(png_ptr->transformations & PNG_INTERLACE))
1792
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1793
png_pass_ystart[0]) / png_pass_yinc[0];
1794
png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1795
png_pass_start[0]) / png_pass_inc[0];
1799
png_ptr->num_rows = png_ptr->height;
1800
png_ptr->usr_width = png_ptr->width;
1806
png_ptr->num_rows = png_ptr->height;
1807
png_ptr->usr_width = png_ptr->width;
1809
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1810
png_ptr->zstream.next_out = png_ptr->zbuf;
1813
/* Internal use only. Called when finished processing a row of data. */
1815
png_write_finish_row(png_structp png_ptr)
1817
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1818
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1820
/* Start of interlace block */
1821
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1823
/* Offset to next interlace block */
1824
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1826
/* Start of interlace block in the y direction */
1827
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1829
/* Offset to next interlace block in the y direction */
1830
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1835
png_debug(1, "in png_write_finish_row");
1838
png_ptr->row_number++;
1840
/* See if we are done */
1841
if (png_ptr->row_number < png_ptr->num_rows)
1844
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1845
/* If interlaced, go to next pass */
1846
if (png_ptr->interlaced)
1848
png_ptr->row_number = 0;
1849
if (png_ptr->transformations & PNG_INTERLACE)
1855
/* Loop until we find a non-zero width or height pass */
1859
if (png_ptr->pass >= 7)
1861
png_ptr->usr_width = (png_ptr->width +
1862
png_pass_inc[png_ptr->pass] - 1 -
1863
png_pass_start[png_ptr->pass]) /
1864
png_pass_inc[png_ptr->pass];
1865
png_ptr->num_rows = (png_ptr->height +
1866
png_pass_yinc[png_ptr->pass] - 1 -
1867
png_pass_ystart[png_ptr->pass]) /
1868
png_pass_yinc[png_ptr->pass];
1869
if (png_ptr->transformations & PNG_INTERLACE)
1871
} while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1875
/* Reset the row above the image for the next pass */
1876
if (png_ptr->pass < 7)
1878
if (png_ptr->prev_row != NULL)
1879
png_memset(png_ptr->prev_row, 0,
1880
(png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
1881
png_ptr->usr_bit_depth, png_ptr->width)) + 1);
1887
/* If we get here, we've just written the last row, so we need
1888
to flush the compressor */
1891
/* Tell the compressor we are done */
1892
ret = deflate(&png_ptr->zstream, Z_FINISH);
1893
/* Check for an error */
1896
/* Check to see if we need more room */
1897
if (!(png_ptr->zstream.avail_out))
1899
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1900
png_ptr->zstream.next_out = png_ptr->zbuf;
1901
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1904
else if (ret != Z_STREAM_END)
1906
if (png_ptr->zstream.msg != NULL)
1907
png_error(png_ptr, png_ptr->zstream.msg);
1909
png_error(png_ptr, "zlib error");
1911
} while (ret != Z_STREAM_END);
1913
/* Write any extra space */
1914
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1916
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1917
png_ptr->zstream.avail_out);
1920
deflateReset(&png_ptr->zstream);
1921
png_ptr->zstream.data_type = Z_BINARY;
1924
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1925
/* Pick out the correct pixels for the interlace pass.
1926
* The basic idea here is to go through the row with a source
1927
* pointer and a destination pointer (sp and dp), and copy the
1928
* correct pixels for the pass. As the row gets compacted,
1929
* sp will always be >= dp, so we should never overwrite anything.
1930
* See the default: case for the easiest code to understand.
1933
png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
1935
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1937
/* Start of interlace block */
1938
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1940
/* Offset to next interlace block */
1941
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1943
png_debug(1, "in png_do_write_interlace");
1945
/* We don't have to do anything on the last pass (6) */
1948
/* Each pixel depth is handled separately */
1949
switch (row_info->pixel_depth)
1959
png_uint_32 row_width = row_info->width;
1964
for (i = png_pass_start[pass]; i < row_width;
1965
i += png_pass_inc[pass])
1967
sp = row + (png_size_t)(i >> 3);
1968
value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
1969
d |= (value << shift);
1974
*dp++ = (png_byte)d;
1993
png_uint_32 row_width = row_info->width;
1998
for (i = png_pass_start[pass]; i < row_width;
1999
i += png_pass_inc[pass])
2001
sp = row + (png_size_t)(i >> 2);
2002
value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
2003
d |= (value << shift);
2008
*dp++ = (png_byte)d;
2026
png_uint_32 row_width = row_info->width;
2031
for (i = png_pass_start[pass]; i < row_width;
2032
i += png_pass_inc[pass])
2034
sp = row + (png_size_t)(i >> 1);
2035
value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
2036
d |= (value << shift);
2041
*dp++ = (png_byte)d;
2056
png_uint_32 row_width = row_info->width;
2057
png_size_t pixel_bytes;
2059
/* Start at the beginning */
2061
/* Find out how many bytes each pixel takes up */
2062
pixel_bytes = (row_info->pixel_depth >> 3);
2063
/* Loop through the row, only looking at the pixels that
2065
for (i = png_pass_start[pass]; i < row_width;
2066
i += png_pass_inc[pass])
2068
/* Find out where the original pixel is */
2069
sp = row + (png_size_t)i * pixel_bytes;
2070
/* Move the pixel */
2072
png_memcpy(dp, sp, pixel_bytes);
2079
/* Set new row width */
2080
row_info->width = (row_info->width +
2081
png_pass_inc[pass] - 1 -
2082
png_pass_start[pass]) /
2084
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2090
/* This filters the row, chooses which filter to use, if it has not already
2091
* been specified by the application, and then writes the row out with the
2094
#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
2095
#define PNG_HISHIFT 10
2096
#define PNG_LOMASK ((png_uint_32)0xffffL)
2097
#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2099
png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2102
#ifdef PNG_WRITE_FILTER_SUPPORTED
2103
png_bytep prev_row, row_buf;
2104
png_uint_32 mins, bpp;
2105
png_byte filter_to_do = png_ptr->do_filter;
2106
png_uint_32 row_bytes = row_info->rowbytes;
2107
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2108
int num_p_filters = (int)png_ptr->num_prev_filters;
2111
png_debug(1, "in png_write_find_filter");
2113
#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2114
if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
2116
/* These will never be selected so we need not test them. */
2117
filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
2121
/* Find out how many bytes offset each pixel is */
2122
bpp = (row_info->pixel_depth + 7) >> 3;
2124
prev_row = png_ptr->prev_row;
2126
best_row = png_ptr->row_buf;
2127
#ifdef PNG_WRITE_FILTER_SUPPORTED
2131
/* The prediction method we use is to find which method provides the
2132
* smallest value when summing the absolute values of the distances
2133
* from zero, using anything >= 128 as negative numbers. This is known
2134
* as the "minimum sum of absolute differences" heuristic. Other
2135
* heuristics are the "weighted minimum sum of absolute differences"
2136
* (experimental and can in theory improve compression), and the "zlib
2137
* predictive" method (not implemented yet), which does test compressions
2138
* of lines using different filter methods, and then chooses the
2139
* (series of) filter(s) that give minimum compressed data size (VERY
2140
* computationally expensive).
2142
* GRR 980525: consider also
2143
* (1) minimum sum of absolute differences from running average (i.e.,
2144
* keep running sum of non-absolute differences & count of bytes)
2145
* [track dispersion, too? restart average if dispersion too large?]
2146
* (1b) minimum sum of absolute differences from sliding average, probably
2147
* with window size <= deflate window (usually 32K)
2148
* (2) minimum sum of squared differences from zero or running average
2149
* (i.e., ~ root-mean-square approach)
2153
/* We don't need to test the 'no filter' case if this is the only filter
2154
* that has been chosen, as it doesn't actually do anything to the data.
2156
if ((filter_to_do & PNG_FILTER_NONE) &&
2157
filter_to_do != PNG_FILTER_NONE)
2160
png_uint_32 sum = 0;
2164
for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2167
sum += (v < 128) ? v : 256 - v;
2170
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2171
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2173
png_uint_32 sumhi, sumlo;
2175
sumlo = sum & PNG_LOMASK;
2176
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2178
/* Reduce the sum if we match any of the previous rows */
2179
for (j = 0; j < num_p_filters; j++)
2181
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2183
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2185
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2190
/* Factor in the cost of this filter (this is here for completeness,
2191
* but it makes no sense to have a "cost" for the NONE filter, as
2192
* it has the minimum possible computational cost - none).
2194
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2196
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2199
if (sumhi > PNG_HIMASK)
2202
sum = (sumhi << PNG_HISHIFT) + sumlo;
2209
if (filter_to_do == PNG_FILTER_SUB)
2210
/* It's the only filter so no testing is needed */
2212
png_bytep rp, lp, dp;
2214
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2219
for (lp = row_buf + 1; i < row_bytes;
2220
i++, rp++, lp++, dp++)
2222
*dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2224
best_row = png_ptr->sub_row;
2227
else if (filter_to_do & PNG_FILTER_SUB)
2229
png_bytep rp, dp, lp;
2230
png_uint_32 sum = 0, lmins = mins;
2234
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2235
/* We temporarily increase the "minimum sum" by the factor we
2236
* would reduce the sum of this filter, so that we can do the
2237
* early exit comparison without scaling the sum each time.
2239
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2242
png_uint_32 lmhi, lmlo;
2243
lmlo = lmins & PNG_LOMASK;
2244
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2246
for (j = 0; j < num_p_filters; j++)
2248
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2250
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2252
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2257
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2259
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2262
if (lmhi > PNG_HIMASK)
2265
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2269
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2274
sum += (v < 128) ? v : 256 - v;
2276
for (lp = row_buf + 1; i < row_bytes;
2277
i++, rp++, lp++, dp++)
2279
v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2281
sum += (v < 128) ? v : 256 - v;
2283
if (sum > lmins) /* We are already worse, don't continue. */
2287
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2288
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2291
png_uint_32 sumhi, sumlo;
2292
sumlo = sum & PNG_LOMASK;
2293
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2295
for (j = 0; j < num_p_filters; j++)
2297
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2299
sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2301
sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2306
sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2308
sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2311
if (sumhi > PNG_HIMASK)
2314
sum = (sumhi << PNG_HISHIFT) + sumlo;
2321
best_row = png_ptr->sub_row;
2326
if (filter_to_do == PNG_FILTER_UP)
2328
png_bytep rp, dp, pp;
2331
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2332
pp = prev_row + 1; i < row_bytes;
2333
i++, rp++, pp++, dp++)
2335
*dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2337
best_row = png_ptr->up_row;
2340
else if (filter_to_do & PNG_FILTER_UP)
2342
png_bytep rp, dp, pp;
2343
png_uint_32 sum = 0, lmins = mins;
2348
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2349
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2352
png_uint_32 lmhi, lmlo;
2353
lmlo = lmins & PNG_LOMASK;
2354
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2356
for (j = 0; j < num_p_filters; j++)
2358
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2360
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2362
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2367
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2369
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2372
if (lmhi > PNG_HIMASK)
2375
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2379
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2380
pp = prev_row + 1; i < row_bytes; i++)
2382
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2384
sum += (v < 128) ? v : 256 - v;
2386
if (sum > lmins) /* We are already worse, don't continue. */
2390
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2391
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2394
png_uint_32 sumhi, sumlo;
2395
sumlo = sum & PNG_LOMASK;
2396
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2398
for (j = 0; j < num_p_filters; j++)
2400
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2402
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2404
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2409
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2411
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2414
if (sumhi > PNG_HIMASK)
2417
sum = (sumhi << PNG_HISHIFT) + sumlo;
2424
best_row = png_ptr->up_row;
2429
if (filter_to_do == PNG_FILTER_AVG)
2431
png_bytep rp, dp, pp, lp;
2433
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2434
pp = prev_row + 1; i < bpp; i++)
2436
*dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2438
for (lp = row_buf + 1; i < row_bytes; i++)
2440
*dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2443
best_row = png_ptr->avg_row;
2446
else if (filter_to_do & PNG_FILTER_AVG)
2448
png_bytep rp, dp, pp, lp;
2449
png_uint_32 sum = 0, lmins = mins;
2453
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2454
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2457
png_uint_32 lmhi, lmlo;
2458
lmlo = lmins & PNG_LOMASK;
2459
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2461
for (j = 0; j < num_p_filters; j++)
2463
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2465
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2467
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2472
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2474
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2477
if (lmhi > PNG_HIMASK)
2480
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2484
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2485
pp = prev_row + 1; i < bpp; i++)
2487
v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2489
sum += (v < 128) ? v : 256 - v;
2491
for (lp = row_buf + 1; i < row_bytes; i++)
2494
(png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2496
sum += (v < 128) ? v : 256 - v;
2498
if (sum > lmins) /* We are already worse, don't continue. */
2502
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2503
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2506
png_uint_32 sumhi, sumlo;
2507
sumlo = sum & PNG_LOMASK;
2508
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2510
for (j = 0; j < num_p_filters; j++)
2512
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2514
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2516
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2521
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2523
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2526
if (sumhi > PNG_HIMASK)
2529
sum = (sumhi << PNG_HISHIFT) + sumlo;
2536
best_row = png_ptr->avg_row;
2541
if (filter_to_do == PNG_FILTER_PAETH)
2543
png_bytep rp, dp, pp, cp, lp;
2545
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2546
pp = prev_row + 1; i < bpp; i++)
2548
*dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2551
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2553
int a, b, c, pa, pb, pc, p;
2567
pa = p < 0 ? -p : p;
2568
pb = pc < 0 ? -pc : pc;
2569
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2572
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2574
*dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2576
best_row = png_ptr->paeth_row;
2579
else if (filter_to_do & PNG_FILTER_PAETH)
2581
png_bytep rp, dp, pp, cp, lp;
2582
png_uint_32 sum = 0, lmins = mins;
2586
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2587
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2590
png_uint_32 lmhi, lmlo;
2591
lmlo = lmins & PNG_LOMASK;
2592
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2594
for (j = 0; j < num_p_filters; j++)
2596
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2598
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2600
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2605
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2607
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2610
if (lmhi > PNG_HIMASK)
2613
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2617
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2618
pp = prev_row + 1; i < bpp; i++)
2620
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2622
sum += (v < 128) ? v : 256 - v;
2625
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2627
int a, b, c, pa, pb, pc, p;
2633
#ifndef PNG_SLOW_PAETH
2641
pa = p < 0 ? -p : p;
2642
pb = pc < 0 ? -pc : pc;
2643
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2645
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2646
#else /* PNG_SLOW_PAETH */
2651
if (pa <= pb && pa <= pc)
2657
#endif /* PNG_SLOW_PAETH */
2659
v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2661
sum += (v < 128) ? v : 256 - v;
2663
if (sum > lmins) /* We are already worse, don't continue. */
2667
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2668
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2671
png_uint_32 sumhi, sumlo;
2672
sumlo = sum & PNG_LOMASK;
2673
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2675
for (j = 0; j < num_p_filters; j++)
2677
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2679
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2681
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2686
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2688
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2691
if (sumhi > PNG_HIMASK)
2694
sum = (sumhi << PNG_HISHIFT) + sumlo;
2700
best_row = png_ptr->paeth_row;
2703
#endif /* PNG_WRITE_FILTER_SUPPORTED */
2704
/* Do the actual writing of the filtered row data from the chosen filter. */
2706
png_write_filtered_row(png_ptr, best_row);
2708
#ifdef PNG_WRITE_FILTER_SUPPORTED
2709
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
2710
/* Save the type of filter we picked this time for future calculations */
2711
if (png_ptr->num_prev_filters > 0)
2714
for (j = 1; j < num_p_filters; j++)
2716
png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
2718
png_ptr->prev_filters[j] = best_row[0];
2721
#endif /* PNG_WRITE_FILTER_SUPPORTED */
2725
/* Do the actual writing of a previously filtered row. */
2727
png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2729
png_debug(1, "in png_write_filtered_row");
2731
png_debug1(2, "filter = %d", filtered_row[0]);
2732
/* Set up the zlib input buffer */
2734
png_ptr->zstream.next_in = filtered_row;
2735
png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
2736
/* Repeat until we have compressed all the data */
2739
int ret; /* Return of zlib */
2741
/* Compress the data */
2742
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2743
/* Check for compression errors */
2746
if (png_ptr->zstream.msg != NULL)
2747
png_error(png_ptr, png_ptr->zstream.msg);
2749
png_error(png_ptr, "zlib error");
2752
/* See if it is time to write another IDAT */
2753
if (!(png_ptr->zstream.avail_out))
2755
/* Write the IDAT and reset the zlib output buffer */
2756
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2757
png_ptr->zstream.next_out = png_ptr->zbuf;
2758
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2760
/* Repeat until all data has been compressed */
2761
} while (png_ptr->zstream.avail_in);
2763
/* Swap the current and previous rows */
2764
if (png_ptr->prev_row != NULL)
2768
tptr = png_ptr->prev_row;
2769
png_ptr->prev_row = png_ptr->row_buf;
2770
png_ptr->row_buf = tptr;
2773
/* Finish row - updates counters and flushes zlib if last row */
2774
png_write_finish_row(png_ptr);
2776
#ifdef PNG_WRITE_FLUSH_SUPPORTED
2777
png_ptr->flush_rows++;
2779
if (png_ptr->flush_dist > 0 &&
2780
png_ptr->flush_rows >= png_ptr->flush_dist)
2782
png_write_flush(png_ptr);
2786
#endif /* PNG_WRITE_SUPPORTED */
added
removed
source/Irrlicht/libpng/pngwutil.c
