2 /* pngwrite.c - general routines to write a PNG file
4 * Last changed in libpng 1.6.2 [April 25, 2013]
5 * Copyright (c) 1998-2013 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.)
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
15 #if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
19 #ifdef PNG_WRITE_SUPPORTED
21 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
22 /* Write out all the unknown chunks for the current given location */
24 write_unknown_chunks(png_structrp png_ptr
, png_const_inforp info_ptr
,
27 if (info_ptr
->unknown_chunks_num
)
29 png_const_unknown_chunkp up
;
31 png_debug(5, "writing extra chunks");
33 for (up
= info_ptr
->unknown_chunks
;
34 up
< info_ptr
->unknown_chunks
+ info_ptr
->unknown_chunks_num
;
36 if (up
->location
& where
)
38 /* If per-chunk unknown chunk handling is enabled use it, otherwise
39 * just write the chunks the application has set.
41 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
42 int keep
= png_handle_as_unknown(png_ptr
, up
->name
);
44 /* NOTE: this code is radically different from the read side in the
45 * matter of handling an ancillary unknown chunk. In the read side
46 * the default behavior is to discard it, in the code below the default
47 * behavior is to write it. Critical chunks are, however, only
48 * written if explicitly listed or if the default is set to write all
51 * The default handling is also slightly weird - it is not possible to
52 * stop the writing of all unsafe-to-copy chunks!
54 * TODO: REVIEW: this would seem to be a bug.
56 if (keep
!= PNG_HANDLE_CHUNK_NEVER
&&
57 ((up
->name
[3] & 0x20) /* safe-to-copy overrides everything */ ||
58 keep
== PNG_HANDLE_CHUNK_ALWAYS
||
59 (keep
== PNG_HANDLE_CHUNK_AS_DEFAULT
&&
60 png_ptr
->unknown_default
== PNG_HANDLE_CHUNK_ALWAYS
)))
63 /* TODO: review, what is wrong with a zero length unknown chunk? */
65 png_warning(png_ptr
, "Writing zero-length unknown chunk");
67 png_write_chunk(png_ptr
, up
->name
, up
->data
, up
->size
);
72 #endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
74 /* Writes all the PNG information. This is the suggested way to use the
75 * library. If you have a new chunk to add, make a function to write it,
76 * and put it in the correct location here. If you want the chunk written
77 * after the image data, put it in png_write_end(). I strongly encourage
78 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
79 * the chunk, as that will keep the code from breaking if you want to just
80 * write a plain PNG file. If you have long comments, I suggest writing
81 * them in png_write_end(), and compressing them.
84 png_write_info_before_PLTE(png_structrp png_ptr
, png_const_inforp info_ptr
)
86 png_debug(1, "in png_write_info_before_PLTE");
88 if (png_ptr
== NULL
|| info_ptr
== NULL
)
91 if (!(png_ptr
->mode
& PNG_WROTE_INFO_BEFORE_PLTE
))
93 /* Write PNG signature */
94 png_write_sig(png_ptr
);
96 #ifdef PNG_MNG_FEATURES_SUPPORTED
97 if ((png_ptr
->mode
&PNG_HAVE_PNG_SIGNATURE
) && \
98 (png_ptr
->mng_features_permitted
))
100 png_warning(png_ptr
, "MNG features are not allowed in a PNG datastream");
101 png_ptr
->mng_features_permitted
= 0;
105 /* Write IHDR information. */
106 png_write_IHDR(png_ptr
, info_ptr
->width
, info_ptr
->height
,
107 info_ptr
->bit_depth
, info_ptr
->color_type
, info_ptr
->compression_type
,
108 info_ptr
->filter_type
,
109 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
110 info_ptr
->interlace_type
116 /* The rest of these check to see if the valid field has the appropriate
117 * flag set, and if it does, writes the chunk.
119 * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
120 * the chunks will be written if the WRITE routine is there and information
121 * is available in the COLORSPACE. (See png_colorspace_sync_info in png.c
122 * for where the valid flags get set.)
124 * Under certain circumstances the colorspace can be invalidated without
125 * syncing the info_struct 'valid' flags; this happens if libpng detects and
126 * error and calls png_error while the color space is being set, yet the
127 * application continues writing the PNG. So check the 'invalid' flag here
130 #ifdef PNG_WRITE_APNG_SUPPORTED
131 if (info_ptr
->valid
& PNG_INFO_acTL
)
132 png_write_acTL(png_ptr
, info_ptr
->num_frames
, info_ptr
->num_plays
);
134 #ifdef PNG_GAMMA_SUPPORTED
135 # ifdef PNG_WRITE_gAMA_SUPPORTED
136 if (!(info_ptr
->colorspace
.flags
& PNG_COLORSPACE_INVALID
) &&
137 (info_ptr
->colorspace
.flags
& PNG_COLORSPACE_FROM_gAMA
) &&
138 (info_ptr
->valid
& PNG_INFO_gAMA
))
139 png_write_gAMA_fixed(png_ptr
, info_ptr
->colorspace
.gamma
);
143 #ifdef PNG_COLORSPACE_SUPPORTED
144 /* Write only one of sRGB or an ICC profile. If a profile was supplied
145 * and it matches one of the known sRGB ones issue a warning.
147 # ifdef PNG_WRITE_iCCP_SUPPORTED
148 if (!(info_ptr
->colorspace
.flags
& PNG_COLORSPACE_INVALID
) &&
149 (info_ptr
->valid
& PNG_INFO_iCCP
))
151 # ifdef PNG_WRITE_sRGB_SUPPORTED
152 if (info_ptr
->valid
& PNG_INFO_sRGB
)
153 png_app_warning(png_ptr
,
154 "profile matches sRGB but writing iCCP instead");
157 png_write_iCCP(png_ptr
, info_ptr
->iccp_name
,
158 info_ptr
->iccp_profile
);
160 # ifdef PNG_WRITE_sRGB_SUPPORTED
165 # ifdef PNG_WRITE_sRGB_SUPPORTED
166 if (!(info_ptr
->colorspace
.flags
& PNG_COLORSPACE_INVALID
) &&
167 (info_ptr
->valid
& PNG_INFO_sRGB
))
168 png_write_sRGB(png_ptr
, info_ptr
->colorspace
.rendering_intent
);
169 # endif /* WRITE_sRGB */
170 #endif /* COLORSPACE */
172 #ifdef PNG_WRITE_sBIT_SUPPORTED
173 if (info_ptr
->valid
& PNG_INFO_sBIT
)
174 png_write_sBIT(png_ptr
, &(info_ptr
->sig_bit
), info_ptr
->color_type
);
177 #ifdef PNG_COLORSPACE_SUPPORTED
178 # ifdef PNG_WRITE_cHRM_SUPPORTED
179 if (!(info_ptr
->colorspace
.flags
& PNG_COLORSPACE_INVALID
) &&
180 (info_ptr
->colorspace
.flags
& PNG_COLORSPACE_FROM_cHRM
) &&
181 (info_ptr
->valid
& PNG_INFO_cHRM
))
182 png_write_cHRM_fixed(png_ptr
, &info_ptr
->colorspace
.end_points_xy
);
186 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
187 write_unknown_chunks(png_ptr
, info_ptr
, PNG_HAVE_IHDR
);
190 png_ptr
->mode
|= PNG_WROTE_INFO_BEFORE_PLTE
;
195 png_write_info(png_structrp png_ptr
, png_const_inforp info_ptr
)
197 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
201 png_debug(1, "in png_write_info");
203 if (png_ptr
== NULL
|| info_ptr
== NULL
)
206 png_write_info_before_PLTE(png_ptr
, info_ptr
);
208 if (info_ptr
->valid
& PNG_INFO_PLTE
)
209 png_write_PLTE(png_ptr
, info_ptr
->palette
,
210 (png_uint_32
)info_ptr
->num_palette
);
212 else if (info_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
213 png_error(png_ptr
, "Valid palette required for paletted images");
215 #ifdef PNG_WRITE_tRNS_SUPPORTED
216 if (info_ptr
->valid
& PNG_INFO_tRNS
)
218 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
219 /* Invert the alpha channel (in tRNS) */
220 if ((png_ptr
->transformations
& PNG_INVERT_ALPHA
) &&
221 info_ptr
->color_type
== PNG_COLOR_TYPE_PALETTE
)
224 for (j
= 0; j
<(int)info_ptr
->num_trans
; j
++)
225 info_ptr
->trans_alpha
[j
] =
226 (png_byte
)(255 - info_ptr
->trans_alpha
[j
]);
229 png_write_tRNS(png_ptr
, info_ptr
->trans_alpha
, &(info_ptr
->trans_color
),
230 info_ptr
->num_trans
, info_ptr
->color_type
);
233 #ifdef PNG_WRITE_bKGD_SUPPORTED
234 if (info_ptr
->valid
& PNG_INFO_bKGD
)
235 png_write_bKGD(png_ptr
, &(info_ptr
->background
), info_ptr
->color_type
);
238 #ifdef PNG_WRITE_hIST_SUPPORTED
239 if (info_ptr
->valid
& PNG_INFO_hIST
)
240 png_write_hIST(png_ptr
, info_ptr
->hist
, info_ptr
->num_palette
);
243 #ifdef PNG_WRITE_oFFs_SUPPORTED
244 if (info_ptr
->valid
& PNG_INFO_oFFs
)
245 png_write_oFFs(png_ptr
, info_ptr
->x_offset
, info_ptr
->y_offset
,
246 info_ptr
->offset_unit_type
);
249 #ifdef PNG_WRITE_pCAL_SUPPORTED
250 if (info_ptr
->valid
& PNG_INFO_pCAL
)
251 png_write_pCAL(png_ptr
, info_ptr
->pcal_purpose
, info_ptr
->pcal_X0
,
252 info_ptr
->pcal_X1
, info_ptr
->pcal_type
, info_ptr
->pcal_nparams
,
253 info_ptr
->pcal_units
, info_ptr
->pcal_params
);
256 #ifdef PNG_WRITE_sCAL_SUPPORTED
257 if (info_ptr
->valid
& PNG_INFO_sCAL
)
258 png_write_sCAL_s(png_ptr
, (int)info_ptr
->scal_unit
,
259 info_ptr
->scal_s_width
, info_ptr
->scal_s_height
);
262 #ifdef PNG_WRITE_pHYs_SUPPORTED
263 if (info_ptr
->valid
& PNG_INFO_pHYs
)
264 png_write_pHYs(png_ptr
, info_ptr
->x_pixels_per_unit
,
265 info_ptr
->y_pixels_per_unit
, info_ptr
->phys_unit_type
);
268 #ifdef PNG_WRITE_tIME_SUPPORTED
269 if (info_ptr
->valid
& PNG_INFO_tIME
)
271 png_write_tIME(png_ptr
, &(info_ptr
->mod_time
));
272 png_ptr
->mode
|= PNG_WROTE_tIME
;
276 #ifdef PNG_WRITE_sPLT_SUPPORTED
277 if (info_ptr
->valid
& PNG_INFO_sPLT
)
278 for (i
= 0; i
< (int)info_ptr
->splt_palettes_num
; i
++)
279 png_write_sPLT(png_ptr
, info_ptr
->splt_palettes
+ i
);
282 #ifdef PNG_WRITE_TEXT_SUPPORTED
283 /* Check to see if we need to write text chunks */
284 for (i
= 0; i
< info_ptr
->num_text
; i
++)
286 png_debug2(2, "Writing header text chunk %d, type %d", i
,
287 info_ptr
->text
[i
].compression
);
288 /* An internationalized chunk? */
289 if (info_ptr
->text
[i
].compression
> 0)
291 #ifdef PNG_WRITE_iTXt_SUPPORTED
292 /* Write international chunk */
293 png_write_iTXt(png_ptr
,
294 info_ptr
->text
[i
].compression
,
295 info_ptr
->text
[i
].key
,
296 info_ptr
->text
[i
].lang
,
297 info_ptr
->text
[i
].lang_key
,
298 info_ptr
->text
[i
].text
);
300 png_warning(png_ptr
, "Unable to write international text");
302 /* Mark this chunk as written */
303 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_NONE_WR
;
306 /* If we want a compressed text chunk */
307 else if (info_ptr
->text
[i
].compression
== PNG_TEXT_COMPRESSION_zTXt
)
309 #ifdef PNG_WRITE_zTXt_SUPPORTED
310 /* Write compressed chunk */
311 png_write_zTXt(png_ptr
, info_ptr
->text
[i
].key
,
312 info_ptr
->text
[i
].text
, 0,
313 info_ptr
->text
[i
].compression
);
315 png_warning(png_ptr
, "Unable to write compressed text");
317 /* Mark this chunk as written */
318 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_zTXt_WR
;
321 else if (info_ptr
->text
[i
].compression
== PNG_TEXT_COMPRESSION_NONE
)
323 #ifdef PNG_WRITE_tEXt_SUPPORTED
324 /* Write uncompressed chunk */
325 png_write_tEXt(png_ptr
, info_ptr
->text
[i
].key
,
326 info_ptr
->text
[i
].text
,
328 /* Mark this chunk as written */
329 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_NONE_WR
;
332 png_warning(png_ptr
, "Unable to write uncompressed text");
338 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
339 write_unknown_chunks(png_ptr
, info_ptr
, PNG_HAVE_PLTE
);
343 /* Writes the end of the PNG file. If you don't want to write comments or
344 * time information, you can pass NULL for info. If you already wrote these
345 * in png_write_info(), do not write them again here. If you have long
346 * comments, I suggest writing them here, and compressing them.
349 png_write_end(png_structrp png_ptr
, png_inforp info_ptr
)
351 png_debug(1, "in png_write_end");
356 if (!(png_ptr
->mode
& PNG_HAVE_IDAT
))
357 png_error(png_ptr
, "No IDATs written into file");
359 #ifdef PNG_WRITE_APNG_SUPPORTED
360 if (png_ptr
->num_frames_written
!= png_ptr
->num_frames_to_write
)
361 png_error(png_ptr
, "Not enough frames written");
364 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
365 if (png_ptr
->num_palette_max
> png_ptr
->num_palette
)
366 png_benign_error(png_ptr
, "Wrote palette index exceeding num_palette");
369 /* See if user wants us to write information chunks */
370 if (info_ptr
!= NULL
)
372 #ifdef PNG_WRITE_TEXT_SUPPORTED
373 int i
; /* local index variable */
375 #ifdef PNG_WRITE_tIME_SUPPORTED
376 /* Check to see if user has supplied a time chunk */
377 if ((info_ptr
->valid
& PNG_INFO_tIME
) &&
378 !(png_ptr
->mode
& PNG_WROTE_tIME
))
379 png_write_tIME(png_ptr
, &(info_ptr
->mod_time
));
382 #ifdef PNG_WRITE_TEXT_SUPPORTED
383 /* Loop through comment chunks */
384 for (i
= 0; i
< info_ptr
->num_text
; i
++)
386 png_debug2(2, "Writing trailer text chunk %d, type %d", i
,
387 info_ptr
->text
[i
].compression
);
388 /* An internationalized chunk? */
389 if (info_ptr
->text
[i
].compression
> 0)
391 #ifdef PNG_WRITE_iTXt_SUPPORTED
392 /* Write international chunk */
393 png_write_iTXt(png_ptr
,
394 info_ptr
->text
[i
].compression
,
395 info_ptr
->text
[i
].key
,
396 info_ptr
->text
[i
].lang
,
397 info_ptr
->text
[i
].lang_key
,
398 info_ptr
->text
[i
].text
);
400 png_warning(png_ptr
, "Unable to write international text");
402 /* Mark this chunk as written */
403 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_NONE_WR
;
406 else if (info_ptr
->text
[i
].compression
>= PNG_TEXT_COMPRESSION_zTXt
)
408 #ifdef PNG_WRITE_zTXt_SUPPORTED
409 /* Write compressed chunk */
410 png_write_zTXt(png_ptr
, info_ptr
->text
[i
].key
,
411 info_ptr
->text
[i
].text
, 0,
412 info_ptr
->text
[i
].compression
);
414 png_warning(png_ptr
, "Unable to write compressed text");
416 /* Mark this chunk as written */
417 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_zTXt_WR
;
420 else if (info_ptr
->text
[i
].compression
== PNG_TEXT_COMPRESSION_NONE
)
422 #ifdef PNG_WRITE_tEXt_SUPPORTED
423 /* Write uncompressed chunk */
424 png_write_tEXt(png_ptr
, info_ptr
->text
[i
].key
,
425 info_ptr
->text
[i
].text
, 0);
427 png_warning(png_ptr
, "Unable to write uncompressed text");
430 /* Mark this chunk as written */
431 info_ptr
->text
[i
].compression
= PNG_TEXT_COMPRESSION_NONE_WR
;
435 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
436 write_unknown_chunks(png_ptr
, info_ptr
, PNG_AFTER_IDAT
);
440 png_ptr
->mode
|= PNG_AFTER_IDAT
;
442 /* Write end of PNG file */
443 png_write_IEND(png_ptr
);
444 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
445 * and restored again in libpng-1.2.30, may cause some applications that
446 * do not set png_ptr->output_flush_fn to crash. If your application
447 * experiences a problem, please try building libpng with
448 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
449 * png-mng-implement at lists.sf.net .
451 #ifdef PNG_WRITE_FLUSH_SUPPORTED
452 # ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
458 #ifdef PNG_CONVERT_tIME_SUPPORTED
460 png_convert_from_struct_tm(png_timep ptime
, PNG_CONST
struct tm
* ttime
)
462 png_debug(1, "in png_convert_from_struct_tm");
464 ptime
->year
= (png_uint_16
)(1900 + ttime
->tm_year
);
465 ptime
->month
= (png_byte
)(ttime
->tm_mon
+ 1);
466 ptime
->day
= (png_byte
)ttime
->tm_mday
;
467 ptime
->hour
= (png_byte
)ttime
->tm_hour
;
468 ptime
->minute
= (png_byte
)ttime
->tm_min
;
469 ptime
->second
= (png_byte
)ttime
->tm_sec
;
473 png_convert_from_time_t(png_timep ptime
, time_t ttime
)
477 png_debug(1, "in png_convert_from_time_t");
479 tbuf
= gmtime(&ttime
);
480 png_convert_from_struct_tm(ptime
, tbuf
);
484 /* Initialize png_ptr structure, and allocate any memory needed */
485 PNG_FUNCTION(png_structp
,PNGAPI
486 png_create_write_struct
,(png_const_charp user_png_ver
, png_voidp error_ptr
,
487 png_error_ptr error_fn
, png_error_ptr warn_fn
),PNG_ALLOCATED
)
489 #ifndef PNG_USER_MEM_SUPPORTED
490 png_structrp png_ptr
= png_create_png_struct(user_png_ver
, error_ptr
,
491 error_fn
, warn_fn
, NULL
, NULL
, NULL
);
493 return png_create_write_struct_2(user_png_ver
, error_ptr
, error_fn
,
494 warn_fn
, NULL
, NULL
, NULL
);
497 /* Alternate initialize png_ptr structure, and allocate any memory needed */
498 PNG_FUNCTION(png_structp
,PNGAPI
499 png_create_write_struct_2
,(png_const_charp user_png_ver
, png_voidp error_ptr
,
500 png_error_ptr error_fn
, png_error_ptr warn_fn
, png_voidp mem_ptr
,
501 png_malloc_ptr malloc_fn
, png_free_ptr free_fn
),PNG_ALLOCATED
)
503 png_structrp png_ptr
= png_create_png_struct(user_png_ver
, error_ptr
,
504 error_fn
, warn_fn
, mem_ptr
, malloc_fn
, free_fn
);
505 #endif /* PNG_USER_MEM_SUPPORTED */
508 /* Set the zlib control values to defaults; they can be overridden by the
509 * application after the struct has been created.
511 png_ptr
->zbuffer_size
= PNG_ZBUF_SIZE
;
513 /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
514 * pngwutil.c defaults it according to whether or not filters will be
515 * used, and ignores this setting.
517 png_ptr
->zlib_strategy
= PNG_Z_DEFAULT_STRATEGY
;
518 png_ptr
->zlib_level
= PNG_Z_DEFAULT_COMPRESSION
;
519 png_ptr
->zlib_mem_level
= 8;
520 png_ptr
->zlib_window_bits
= 15;
521 png_ptr
->zlib_method
= 8;
523 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
524 png_ptr
->zlib_text_strategy
= PNG_TEXT_Z_DEFAULT_STRATEGY
;
525 png_ptr
->zlib_text_level
= PNG_TEXT_Z_DEFAULT_COMPRESSION
;
526 png_ptr
->zlib_text_mem_level
= 8;
527 png_ptr
->zlib_text_window_bits
= 15;
528 png_ptr
->zlib_text_method
= 8;
529 #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
531 /* This is a highly dubious configuration option; by default it is off,
532 * but it may be appropriate for private builds that are testing
533 * extensions not conformant to the current specification, or of
534 * applications that must not fail to write at all costs!
536 #ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
537 png_ptr
->flags
|= PNG_FLAG_BENIGN_ERRORS_WARN
;
538 /* In stable builds only warn if an application error can be completely
543 /* App warnings are warnings in release (or release candidate) builds but
544 * are errors during development.
546 #if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
547 png_ptr
->flags
|= PNG_FLAG_APP_WARNINGS_WARN
;
550 /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
551 * do it itself) avoiding setting the default function if it is not
554 png_set_write_fn(png_ptr
, NULL
, NULL
, NULL
);
561 /* Write a few rows of image data. If the image is interlaced,
562 * either you will have to write the 7 sub images, or, if you
563 * have called png_set_interlace_handling(), you will have to
564 * "write" the image seven times.
567 png_write_rows(png_structrp png_ptr
, png_bytepp row
,
568 png_uint_32 num_rows
)
570 png_uint_32 i
; /* row counter */
571 png_bytepp rp
; /* row pointer */
573 png_debug(1, "in png_write_rows");
578 /* Loop through the rows */
579 for (i
= 0, rp
= row
; i
< num_rows
; i
++, rp
++)
581 png_write_row(png_ptr
, *rp
);
585 /* Write the image. You only need to call this function once, even
586 * if you are writing an interlaced image.
589 png_write_image(png_structrp png_ptr
, png_bytepp image
)
591 png_uint_32 i
; /* row index */
592 int pass
, num_pass
; /* pass variables */
593 png_bytepp rp
; /* points to current row */
598 png_debug(1, "in png_write_image");
600 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
601 /* Initialize interlace handling. If image is not interlaced,
602 * this will set pass to 1
604 num_pass
= png_set_interlace_handling(png_ptr
);
608 /* Loop through passes */
609 for (pass
= 0; pass
< num_pass
; pass
++)
611 /* Loop through image */
612 for (i
= 0, rp
= image
; i
< png_ptr
->height
; i
++, rp
++)
614 png_write_row(png_ptr
, *rp
);
619 /* Called by user to write a row of image data */
621 png_write_row(png_structrp png_ptr
, png_const_bytep row
)
623 /* 1.5.6: moved from png_struct to be a local structure: */
624 png_row_info row_info
;
629 png_debug2(1, "in png_write_row (row %u, pass %d)",
630 png_ptr
->row_number
, png_ptr
->pass
);
632 /* Initialize transformations and other stuff if first time */
633 if (png_ptr
->row_number
== 0 && png_ptr
->pass
== 0)
635 /* Make sure we wrote the header info */
636 if (!(png_ptr
->mode
& PNG_WROTE_INFO_BEFORE_PLTE
))
638 "png_write_info was never called before png_write_row");
640 /* Check for transforms that have been set but were defined out */
641 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
642 if (png_ptr
->transformations
& PNG_INVERT_MONO
)
643 png_warning(png_ptr
, "PNG_WRITE_INVERT_SUPPORTED is not defined");
646 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
647 if (png_ptr
->transformations
& PNG_FILLER
)
648 png_warning(png_ptr
, "PNG_WRITE_FILLER_SUPPORTED is not defined");
650 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
651 defined(PNG_READ_PACKSWAP_SUPPORTED)
652 if (png_ptr
->transformations
& PNG_PACKSWAP
)
654 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
657 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
658 if (png_ptr
->transformations
& PNG_PACK
)
659 png_warning(png_ptr
, "PNG_WRITE_PACK_SUPPORTED is not defined");
662 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
663 if (png_ptr
->transformations
& PNG_SHIFT
)
664 png_warning(png_ptr
, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
667 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
668 if (png_ptr
->transformations
& PNG_BGR
)
669 png_warning(png_ptr
, "PNG_WRITE_BGR_SUPPORTED is not defined");
672 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
673 if (png_ptr
->transformations
& PNG_SWAP_BYTES
)
674 png_warning(png_ptr
, "PNG_WRITE_SWAP_SUPPORTED is not defined");
677 png_write_start_row(png_ptr
);
680 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
681 /* If interlaced and not interested in row, return */
682 if (png_ptr
->interlaced
&& (png_ptr
->transformations
& PNG_INTERLACE
))
684 switch (png_ptr
->pass
)
687 if (png_ptr
->row_number
& 0x07)
689 png_write_finish_row(png_ptr
);
695 if ((png_ptr
->row_number
& 0x07) || png_ptr
->width
< 5)
697 png_write_finish_row(png_ptr
);
703 if ((png_ptr
->row_number
& 0x07) != 4)
705 png_write_finish_row(png_ptr
);
711 if ((png_ptr
->row_number
& 0x03) || png_ptr
->width
< 3)
713 png_write_finish_row(png_ptr
);
719 if ((png_ptr
->row_number
& 0x03) != 2)
721 png_write_finish_row(png_ptr
);
727 if ((png_ptr
->row_number
& 0x01) || png_ptr
->width
< 2)
729 png_write_finish_row(png_ptr
);
735 if (!(png_ptr
->row_number
& 0x01))
737 png_write_finish_row(png_ptr
);
742 default: /* error: ignore it */
748 /* Set up row info for transformations */
749 row_info
.color_type
= png_ptr
->color_type
;
750 row_info
.width
= png_ptr
->usr_width
;
751 row_info
.channels
= png_ptr
->usr_channels
;
752 row_info
.bit_depth
= png_ptr
->usr_bit_depth
;
753 row_info
.pixel_depth
= (png_byte
)(row_info
.bit_depth
* row_info
.channels
);
754 row_info
.rowbytes
= PNG_ROWBYTES(row_info
.pixel_depth
, row_info
.width
);
756 png_debug1(3, "row_info->color_type = %d", row_info
.color_type
);
757 png_debug1(3, "row_info->width = %u", row_info
.width
);
758 png_debug1(3, "row_info->channels = %d", row_info
.channels
);
759 png_debug1(3, "row_info->bit_depth = %d", row_info
.bit_depth
);
760 png_debug1(3, "row_info->pixel_depth = %d", row_info
.pixel_depth
);
761 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info
.rowbytes
);
763 /* Copy user's row into buffer, leaving room for filter byte. */
764 memcpy(png_ptr
->row_buf
+ 1, row
, row_info
.rowbytes
);
766 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
767 /* Handle interlacing */
768 if (png_ptr
->interlaced
&& png_ptr
->pass
< 6 &&
769 (png_ptr
->transformations
& PNG_INTERLACE
))
771 png_do_write_interlace(&row_info
, png_ptr
->row_buf
+ 1, png_ptr
->pass
);
772 /* This should always get caught above, but still ... */
773 if (!(row_info
.width
))
775 png_write_finish_row(png_ptr
);
781 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
782 /* Handle other transformations */
783 if (png_ptr
->transformations
)
784 png_do_write_transformations(png_ptr
, &row_info
);
787 /* At this point the row_info pixel depth must match the 'transformed' depth,
788 * which is also the output depth.
790 if (row_info
.pixel_depth
!= png_ptr
->pixel_depth
||
791 row_info
.pixel_depth
!= png_ptr
->transformed_pixel_depth
)
792 png_error(png_ptr
, "internal write transform logic error");
794 #ifdef PNG_MNG_FEATURES_SUPPORTED
795 /* Write filter_method 64 (intrapixel differencing) only if
796 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
797 * 2. Libpng did not write a PNG signature (this filter_method is only
798 * used in PNG datastreams that are embedded in MNG datastreams) and
799 * 3. The application called png_permit_mng_features with a mask that
800 * included PNG_FLAG_MNG_FILTER_64 and
801 * 4. The filter_method is 64 and
802 * 5. The color_type is RGB or RGBA
804 if ((png_ptr
->mng_features_permitted
& PNG_FLAG_MNG_FILTER_64
) &&
805 (png_ptr
->filter_type
== PNG_INTRAPIXEL_DIFFERENCING
))
807 /* Intrapixel differencing */
808 png_do_write_intrapixel(&row_info
, png_ptr
->row_buf
+ 1);
812 /* Added at libpng-1.5.10 */
813 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
814 /* Check for out-of-range palette index */
815 if (row_info
.color_type
== PNG_COLOR_TYPE_PALETTE
&&
816 png_ptr
->num_palette_max
>= 0)
817 png_do_check_palette_indexes(png_ptr
, &row_info
);
820 /* Find a filter if necessary, filter the row and write it out. */
821 png_write_find_filter(png_ptr
, &row_info
);
823 if (png_ptr
->write_row_fn
!= NULL
)
824 (*(png_ptr
->write_row_fn
))(png_ptr
, png_ptr
->row_number
, png_ptr
->pass
);
827 #ifdef PNG_WRITE_FLUSH_SUPPORTED
828 /* Set the automatic flush interval or 0 to turn flushing off */
830 png_set_flush(png_structrp png_ptr
, int nrows
)
832 png_debug(1, "in png_set_flush");
837 png_ptr
->flush_dist
= (nrows
< 0 ? 0 : nrows
);
840 /* Flush the current output buffers now */
842 png_write_flush(png_structrp png_ptr
)
844 png_debug(1, "in png_write_flush");
849 /* We have already written out all of the data */
850 if (png_ptr
->row_number
>= png_ptr
->num_rows
)
853 png_compress_IDAT(png_ptr
, NULL
, 0, Z_SYNC_FLUSH
);
854 png_ptr
->flush_rows
= 0;
857 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
859 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
860 static void png_reset_filter_heuristics(png_structrp png_ptr
);/* forward decl */
863 /* Free any memory used in png_ptr struct without freeing the struct itself. */
865 png_write_destroy(png_structrp png_ptr
)
867 png_debug(1, "in png_write_destroy");
869 /* Free any memory zlib uses */
870 if (png_ptr
->flags
& PNG_FLAG_ZSTREAM_INITIALIZED
)
871 deflateEnd(&png_ptr
->zstream
);
873 /* Free our memory. png_free checks NULL for us. */
874 png_free_buffer_list(png_ptr
, &png_ptr
->zbuffer_list
);
875 png_free(png_ptr
, png_ptr
->row_buf
);
876 #ifdef PNG_WRITE_FILTER_SUPPORTED
877 png_free(png_ptr
, png_ptr
->prev_row
);
878 png_free(png_ptr
, png_ptr
->sub_row
);
879 png_free(png_ptr
, png_ptr
->up_row
);
880 png_free(png_ptr
, png_ptr
->avg_row
);
881 png_free(png_ptr
, png_ptr
->paeth_row
);
884 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
885 /* Use this to save a little code space, it doesn't free the filter_costs */
886 png_reset_filter_heuristics(png_ptr
);
887 png_free(png_ptr
, png_ptr
->filter_costs
);
888 png_free(png_ptr
, png_ptr
->inv_filter_costs
);
891 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
892 png_free(png_ptr
, png_ptr
->chunk_list
);
895 /* The error handling and memory handling information is left intact at this
896 * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
897 * for how this happens.
901 /* Free all memory used by the write.
902 * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
903 * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
904 * the passed in info_structs but it would quietly fail to free any of the data
905 * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
909 png_destroy_write_struct(png_structpp png_ptr_ptr
, png_infopp info_ptr_ptr
)
911 png_debug(1, "in png_destroy_write_struct");
913 if (png_ptr_ptr
!= NULL
)
915 png_structrp png_ptr
= *png_ptr_ptr
;
917 if (png_ptr
!= NULL
) /* added in libpng 1.6.0 */
919 png_destroy_info_struct(png_ptr
, info_ptr_ptr
);
922 png_write_destroy(png_ptr
);
923 png_destroy_png_struct(png_ptr
);
928 /* Allow the application to select one or more row filters to use. */
930 png_set_filter(png_structrp png_ptr
, int method
, int filters
)
932 png_debug(1, "in png_set_filter");
937 #ifdef PNG_MNG_FEATURES_SUPPORTED
938 if ((png_ptr
->mng_features_permitted
& PNG_FLAG_MNG_FILTER_64
) &&
939 (method
== PNG_INTRAPIXEL_DIFFERENCING
))
940 method
= PNG_FILTER_TYPE_BASE
;
943 if (method
== PNG_FILTER_TYPE_BASE
)
945 switch (filters
& (PNG_ALL_FILTERS
| 0x07))
947 #ifdef PNG_WRITE_FILTER_SUPPORTED
950 case 7: png_app_error(png_ptr
, "Unknown row filter for method 0");
952 #endif /* PNG_WRITE_FILTER_SUPPORTED */
953 case PNG_FILTER_VALUE_NONE
:
954 png_ptr
->do_filter
= PNG_FILTER_NONE
; break;
956 #ifdef PNG_WRITE_FILTER_SUPPORTED
957 case PNG_FILTER_VALUE_SUB
:
958 png_ptr
->do_filter
= PNG_FILTER_SUB
; break;
960 case PNG_FILTER_VALUE_UP
:
961 png_ptr
->do_filter
= PNG_FILTER_UP
; break;
963 case PNG_FILTER_VALUE_AVG
:
964 png_ptr
->do_filter
= PNG_FILTER_AVG
; break;
966 case PNG_FILTER_VALUE_PAETH
:
967 png_ptr
->do_filter
= PNG_FILTER_PAETH
; break;
970 png_ptr
->do_filter
= (png_byte
)filters
; break;
973 png_app_error(png_ptr
, "Unknown row filter for method 0");
974 #endif /* PNG_WRITE_FILTER_SUPPORTED */
977 /* If we have allocated the row_buf, this means we have already started
978 * with the image and we should have allocated all of the filter buffers
979 * that have been selected. If prev_row isn't already allocated, then
980 * it is too late to start using the filters that need it, since we
981 * will be missing the data in the previous row. If an application
982 * wants to start and stop using particular filters during compression,
983 * it should start out with all of the filters, and then add and
984 * remove them after the start of compression.
986 if (png_ptr
->row_buf
!= NULL
)
988 #ifdef PNG_WRITE_FILTER_SUPPORTED
989 if ((png_ptr
->do_filter
& PNG_FILTER_SUB
) && png_ptr
->sub_row
== NULL
)
991 png_ptr
->sub_row
= (png_bytep
)png_malloc(png_ptr
,
992 (png_ptr
->rowbytes
+ 1));
993 png_ptr
->sub_row
[0] = PNG_FILTER_VALUE_SUB
;
996 if ((png_ptr
->do_filter
& PNG_FILTER_UP
) && png_ptr
->up_row
== NULL
)
998 if (png_ptr
->prev_row
== NULL
)
1000 png_warning(png_ptr
, "Can't add Up filter after starting");
1001 png_ptr
->do_filter
= (png_byte
)(png_ptr
->do_filter
&
1007 png_ptr
->up_row
= (png_bytep
)png_malloc(png_ptr
,
1008 (png_ptr
->rowbytes
+ 1));
1009 png_ptr
->up_row
[0] = PNG_FILTER_VALUE_UP
;
1013 if ((png_ptr
->do_filter
& PNG_FILTER_AVG
) && png_ptr
->avg_row
== NULL
)
1015 if (png_ptr
->prev_row
== NULL
)
1017 png_warning(png_ptr
, "Can't add Average filter after starting");
1018 png_ptr
->do_filter
= (png_byte
)(png_ptr
->do_filter
&
1024 png_ptr
->avg_row
= (png_bytep
)png_malloc(png_ptr
,
1025 (png_ptr
->rowbytes
+ 1));
1026 png_ptr
->avg_row
[0] = PNG_FILTER_VALUE_AVG
;
1030 if ((png_ptr
->do_filter
& PNG_FILTER_PAETH
) &&
1031 png_ptr
->paeth_row
== NULL
)
1033 if (png_ptr
->prev_row
== NULL
)
1035 png_warning(png_ptr
, "Can't add Paeth filter after starting");
1036 png_ptr
->do_filter
&= (png_byte
)(~PNG_FILTER_PAETH
);
1041 png_ptr
->paeth_row
= (png_bytep
)png_malloc(png_ptr
,
1042 (png_ptr
->rowbytes
+ 1));
1043 png_ptr
->paeth_row
[0] = PNG_FILTER_VALUE_PAETH
;
1047 if (png_ptr
->do_filter
== PNG_NO_FILTERS
)
1048 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1049 png_ptr
->do_filter
= PNG_FILTER_NONE
;
1053 png_error(png_ptr
, "Unknown custom filter method");
1056 /* This allows us to influence the way in which libpng chooses the "best"
1057 * filter for the current scanline. While the "minimum-sum-of-absolute-
1058 * differences metric is relatively fast and effective, there is some
1059 * question as to whether it can be improved upon by trying to keep the
1060 * filtered data going to zlib more consistent, hopefully resulting in
1061 * better compression.
1063 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
1064 /* Convenience reset API. */
1066 png_reset_filter_heuristics(png_structrp png_ptr
)
1068 /* Clear out any old values in the 'weights' - this must be done because if
1069 * the app calls set_filter_heuristics multiple times with different
1070 * 'num_weights' values we would otherwise potentially have wrong sized
1073 png_ptr
->num_prev_filters
= 0;
1074 png_ptr
->heuristic_method
= PNG_FILTER_HEURISTIC_UNWEIGHTED
;
1075 if (png_ptr
->prev_filters
!= NULL
)
1077 png_bytep old
= png_ptr
->prev_filters
;
1078 png_ptr
->prev_filters
= NULL
;
1079 png_free(png_ptr
, old
);
1081 if (png_ptr
->filter_weights
!= NULL
)
1083 png_uint_16p old
= png_ptr
->filter_weights
;
1084 png_ptr
->filter_weights
= NULL
;
1085 png_free(png_ptr
, old
);
1088 if (png_ptr
->inv_filter_weights
!= NULL
)
1090 png_uint_16p old
= png_ptr
->inv_filter_weights
;
1091 png_ptr
->inv_filter_weights
= NULL
;
1092 png_free(png_ptr
, old
);
1095 /* Leave the filter_costs - this array is fixed size. */
1099 png_init_filter_heuristics(png_structrp png_ptr
, int heuristic_method
,
1102 if (png_ptr
== NULL
)
1105 /* Clear out the arrays */
1106 png_reset_filter_heuristics(png_ptr
);
1108 /* Check arguments; the 'reset' function makes the correct settings for the
1109 * unweighted case, but we must handle the weight case by initializing the
1110 * arrays for the caller.
1112 if (heuristic_method
== PNG_FILTER_HEURISTIC_WEIGHTED
)
1116 if (num_weights
> 0)
1118 png_ptr
->prev_filters
= (png_bytep
)png_malloc(png_ptr
,
1119 (png_uint_32
)((sizeof (png_byte
)) * num_weights
));
1121 /* To make sure that the weighting starts out fairly */
1122 for (i
= 0; i
< num_weights
; i
++)
1124 png_ptr
->prev_filters
[i
] = 255;
1127 png_ptr
->filter_weights
= (png_uint_16p
)png_malloc(png_ptr
,
1128 (png_uint_32
)((sizeof (png_uint_16
)) * num_weights
));
1130 png_ptr
->inv_filter_weights
= (png_uint_16p
)png_malloc(png_ptr
,
1131 (png_uint_32
)((sizeof (png_uint_16
)) * num_weights
));
1133 for (i
= 0; i
< num_weights
; i
++)
1135 png_ptr
->inv_filter_weights
[i
] =
1136 png_ptr
->filter_weights
[i
] = PNG_WEIGHT_FACTOR
;
1139 /* Safe to set this now */
1140 png_ptr
->num_prev_filters
= (png_byte
)num_weights
;
1143 /* If, in the future, there are other filter methods, this would
1144 * need to be based on png_ptr->filter.
1146 if (png_ptr
->filter_costs
== NULL
)
1148 png_ptr
->filter_costs
= (png_uint_16p
)png_malloc(png_ptr
,
1149 (png_uint_32
)((sizeof (png_uint_16
)) * PNG_FILTER_VALUE_LAST
));
1151 png_ptr
->inv_filter_costs
= (png_uint_16p
)png_malloc(png_ptr
,
1152 (png_uint_32
)((sizeof (png_uint_16
)) * PNG_FILTER_VALUE_LAST
));
1155 for (i
= 0; i
< PNG_FILTER_VALUE_LAST
; i
++)
1157 png_ptr
->inv_filter_costs
[i
] =
1158 png_ptr
->filter_costs
[i
] = PNG_COST_FACTOR
;
1161 /* All the arrays are inited, safe to set this: */
1162 png_ptr
->heuristic_method
= PNG_FILTER_HEURISTIC_WEIGHTED
;
1164 /* Return the 'ok' code. */
1167 else if (heuristic_method
== PNG_FILTER_HEURISTIC_DEFAULT
||
1168 heuristic_method
== PNG_FILTER_HEURISTIC_UNWEIGHTED
)
1174 png_warning(png_ptr
, "Unknown filter heuristic method");
1179 /* Provide floating and fixed point APIs */
1180 #ifdef PNG_FLOATING_POINT_SUPPORTED
1182 png_set_filter_heuristics(png_structrp png_ptr
, int heuristic_method
,
1183 int num_weights
, png_const_doublep filter_weights
,
1184 png_const_doublep filter_costs
)
1186 png_debug(1, "in png_set_filter_heuristics");
1188 /* The internal API allocates all the arrays and ensures that the elements of
1189 * those arrays are set to the default value.
1191 if (!png_init_filter_heuristics(png_ptr
, heuristic_method
, num_weights
))
1194 /* If using the weighted method copy in the weights. */
1195 if (heuristic_method
== PNG_FILTER_HEURISTIC_WEIGHTED
)
1198 for (i
= 0; i
< num_weights
; i
++)
1200 if (filter_weights
[i
] <= 0.0)
1202 png_ptr
->inv_filter_weights
[i
] =
1203 png_ptr
->filter_weights
[i
] = PNG_WEIGHT_FACTOR
;
1208 png_ptr
->inv_filter_weights
[i
] =
1209 (png_uint_16
)(PNG_WEIGHT_FACTOR
*filter_weights
[i
]+.5);
1211 png_ptr
->filter_weights
[i
] =
1212 (png_uint_16
)(PNG_WEIGHT_FACTOR
/filter_weights
[i
]+.5);
1216 /* Here is where we set the relative costs of the different filters. We
1217 * should take the desired compression level into account when setting
1218 * the costs, so that Paeth, for instance, has a high relative cost at low
1219 * compression levels, while it has a lower relative cost at higher
1220 * compression settings. The filter types are in order of increasing
1221 * relative cost, so it would be possible to do this with an algorithm.
1223 for (i
= 0; i
< PNG_FILTER_VALUE_LAST
; i
++) if (filter_costs
[i
] >= 1.0)
1225 png_ptr
->inv_filter_costs
[i
] =
1226 (png_uint_16
)(PNG_COST_FACTOR
/ filter_costs
[i
] + .5);
1228 png_ptr
->filter_costs
[i
] =
1229 (png_uint_16
)(PNG_COST_FACTOR
* filter_costs
[i
] + .5);
1233 #endif /* FLOATING_POINT */
1235 #ifdef PNG_FIXED_POINT_SUPPORTED
1237 png_set_filter_heuristics_fixed(png_structrp png_ptr
, int heuristic_method
,
1238 int num_weights
, png_const_fixed_point_p filter_weights
,
1239 png_const_fixed_point_p filter_costs
)
1241 png_debug(1, "in png_set_filter_heuristics_fixed");
1243 /* The internal API allocates all the arrays and ensures that the elements of
1244 * those arrays are set to the default value.
1246 if (!png_init_filter_heuristics(png_ptr
, heuristic_method
, num_weights
))
1249 /* If using the weighted method copy in the weights. */
1250 if (heuristic_method
== PNG_FILTER_HEURISTIC_WEIGHTED
)
1253 for (i
= 0; i
< num_weights
; i
++)
1255 if (filter_weights
[i
] <= 0)
1257 png_ptr
->inv_filter_weights
[i
] =
1258 png_ptr
->filter_weights
[i
] = PNG_WEIGHT_FACTOR
;
1263 png_ptr
->inv_filter_weights
[i
] = (png_uint_16
)
1264 ((PNG_WEIGHT_FACTOR
*filter_weights
[i
]+PNG_FP_HALF
)/PNG_FP_1
);
1266 png_ptr
->filter_weights
[i
] = (png_uint_16
)((PNG_WEIGHT_FACTOR
*
1267 PNG_FP_1
+(filter_weights
[i
]/2))/filter_weights
[i
]);
1271 /* Here is where we set the relative costs of the different filters. We
1272 * should take the desired compression level into account when setting
1273 * the costs, so that Paeth, for instance, has a high relative cost at low
1274 * compression levels, while it has a lower relative cost at higher
1275 * compression settings. The filter types are in order of increasing
1276 * relative cost, so it would be possible to do this with an algorithm.
1278 for (i
= 0; i
< PNG_FILTER_VALUE_LAST
; i
++)
1279 if (filter_costs
[i
] >= PNG_FP_1
)
1283 /* Use a 32 bit unsigned temporary here because otherwise the
1284 * intermediate value will be a 32 bit *signed* integer (ANSI rules)
1285 * and this will get the wrong answer on division.
1287 tmp
= PNG_COST_FACTOR
*PNG_FP_1
+ (filter_costs
[i
]/2);
1288 tmp
/= filter_costs
[i
];
1290 png_ptr
->inv_filter_costs
[i
] = (png_uint_16
)tmp
;
1292 tmp
= PNG_COST_FACTOR
* filter_costs
[i
] + PNG_FP_HALF
;
1295 png_ptr
->filter_costs
[i
] = (png_uint_16
)tmp
;
1299 #endif /* FIXED_POINT */
1300 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1303 png_set_compression_level(png_structrp png_ptr
, int level
)
1305 png_debug(1, "in png_set_compression_level");
1307 if (png_ptr
== NULL
)
1310 png_ptr
->zlib_level
= level
;
1314 png_set_compression_mem_level(png_structrp png_ptr
, int mem_level
)
1316 png_debug(1, "in png_set_compression_mem_level");
1318 if (png_ptr
== NULL
)
1321 png_ptr
->zlib_mem_level
= mem_level
;
1325 png_set_compression_strategy(png_structrp png_ptr
, int strategy
)
1327 png_debug(1, "in png_set_compression_strategy");
1329 if (png_ptr
== NULL
)
1332 /* The flag setting here prevents the libpng dynamic selection of strategy.
1334 png_ptr
->flags
|= PNG_FLAG_ZLIB_CUSTOM_STRATEGY
;
1335 png_ptr
->zlib_strategy
= strategy
;
1338 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1339 * smaller value of window_bits if it can do so safely.
1342 png_set_compression_window_bits(png_structrp png_ptr
, int window_bits
)
1344 if (png_ptr
== NULL
)
1347 /* Prior to 1.6.0 this would warn but then set the window_bits value, this
1348 * meant that negative window bits values could be selected which would cause
1349 * libpng to write a non-standard PNG file with raw deflate or gzip
1350 * compressed IDAT or ancillary chunks. Such files can be read and there is
1351 * no warning on read, so this seems like a very bad idea.
1353 if (window_bits
> 15)
1355 png_warning(png_ptr
, "Only compression windows <= 32k supported by PNG");
1359 else if (window_bits
< 8)
1361 png_warning(png_ptr
, "Only compression windows >= 256 supported by PNG");
1365 png_ptr
->zlib_window_bits
= window_bits
;
1369 png_set_compression_method(png_structrp png_ptr
, int method
)
1371 png_debug(1, "in png_set_compression_method");
1373 if (png_ptr
== NULL
)
1376 /* This would produce an invalid PNG file if it worked, but it doesn't and
1377 * deflate will fault it, so it is harmless to just warn here.
1380 png_warning(png_ptr
, "Only compression method 8 is supported by PNG");
1382 png_ptr
->zlib_method
= method
;
1385 /* The following were added to libpng-1.5.4 */
1386 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1388 png_set_text_compression_level(png_structrp png_ptr
, int level
)
1390 png_debug(1, "in png_set_text_compression_level");
1392 if (png_ptr
== NULL
)
1395 png_ptr
->zlib_text_level
= level
;
1399 png_set_text_compression_mem_level(png_structrp png_ptr
, int mem_level
)
1401 png_debug(1, "in png_set_text_compression_mem_level");
1403 if (png_ptr
== NULL
)
1406 png_ptr
->zlib_text_mem_level
= mem_level
;
1410 png_set_text_compression_strategy(png_structrp png_ptr
, int strategy
)
1412 png_debug(1, "in png_set_text_compression_strategy");
1414 if (png_ptr
== NULL
)
1417 png_ptr
->zlib_text_strategy
= strategy
;
1420 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1421 * smaller value of window_bits if it can do so safely.
1424 png_set_text_compression_window_bits(png_structrp png_ptr
, int window_bits
)
1426 if (png_ptr
== NULL
)
1429 if (window_bits
> 15)
1431 png_warning(png_ptr
, "Only compression windows <= 32k supported by PNG");
1435 else if (window_bits
< 8)
1437 png_warning(png_ptr
, "Only compression windows >= 256 supported by PNG");
1441 png_ptr
->zlib_text_window_bits
= window_bits
;
1445 png_set_text_compression_method(png_structrp png_ptr
, int method
)
1447 png_debug(1, "in png_set_text_compression_method");
1449 if (png_ptr
== NULL
)
1453 png_warning(png_ptr
, "Only compression method 8 is supported by PNG");
1455 png_ptr
->zlib_text_method
= method
;
1457 #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1458 /* end of API added to libpng-1.5.4 */
1461 png_set_write_status_fn(png_structrp png_ptr
, png_write_status_ptr write_row_fn
)
1463 if (png_ptr
== NULL
)
1466 png_ptr
->write_row_fn
= write_row_fn
;
1469 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1471 png_set_write_user_transform_fn(png_structrp png_ptr
, png_user_transform_ptr
1472 write_user_transform_fn
)
1474 png_debug(1, "in png_set_write_user_transform_fn");
1476 if (png_ptr
== NULL
)
1479 png_ptr
->transformations
|= PNG_USER_TRANSFORM
;
1480 png_ptr
->write_user_transform_fn
= write_user_transform_fn
;
1485 #ifdef PNG_INFO_IMAGE_SUPPORTED
1487 png_write_png(png_structrp png_ptr
, png_inforp info_ptr
,
1488 int transforms
, voidp params
)
1490 if (png_ptr
== NULL
|| info_ptr
== NULL
)
1493 /* Write the file header information. */
1494 png_write_info(png_ptr
, info_ptr
);
1496 /* ------ these transformations don't touch the info structure ------- */
1498 #ifdef PNG_WRITE_INVERT_SUPPORTED
1499 /* Invert monochrome pixels */
1500 if (transforms
& PNG_TRANSFORM_INVERT_MONO
)
1501 png_set_invert_mono(png_ptr
);
1504 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1505 /* Shift the pixels up to a legal bit depth and fill in
1506 * as appropriate to correctly scale the image.
1508 if ((transforms
& PNG_TRANSFORM_SHIFT
)
1509 && (info_ptr
->valid
& PNG_INFO_sBIT
))
1510 png_set_shift(png_ptr
, &info_ptr
->sig_bit
);
1513 #ifdef PNG_WRITE_PACK_SUPPORTED
1514 /* Pack pixels into bytes */
1515 if (transforms
& PNG_TRANSFORM_PACKING
)
1516 png_set_packing(png_ptr
);
1519 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1520 /* Swap location of alpha bytes from ARGB to RGBA */
1521 if (transforms
& PNG_TRANSFORM_SWAP_ALPHA
)
1522 png_set_swap_alpha(png_ptr
);
1525 #ifdef PNG_WRITE_FILLER_SUPPORTED
1526 /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
1527 if (transforms
& PNG_TRANSFORM_STRIP_FILLER_AFTER
)
1528 png_set_filler(png_ptr
, 0, PNG_FILLER_AFTER
);
1530 else if (transforms
& PNG_TRANSFORM_STRIP_FILLER_BEFORE
)
1531 png_set_filler(png_ptr
, 0, PNG_FILLER_BEFORE
);
1534 #ifdef PNG_WRITE_BGR_SUPPORTED
1535 /* Flip BGR pixels to RGB */
1536 if (transforms
& PNG_TRANSFORM_BGR
)
1537 png_set_bgr(png_ptr
);
1540 #ifdef PNG_WRITE_SWAP_SUPPORTED
1541 /* Swap bytes of 16-bit files to most significant byte first */
1542 if (transforms
& PNG_TRANSFORM_SWAP_ENDIAN
)
1543 png_set_swap(png_ptr
);
1546 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1547 /* Swap bits of 1, 2, 4 bit packed pixel formats */
1548 if (transforms
& PNG_TRANSFORM_PACKSWAP
)
1549 png_set_packswap(png_ptr
);
1552 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1553 /* Invert the alpha channel from opacity to transparency */
1554 if (transforms
& PNG_TRANSFORM_INVERT_ALPHA
)
1555 png_set_invert_alpha(png_ptr
);
1558 /* ----------------------- end of transformations ------------------- */
1560 /* Write the bits */
1561 if (info_ptr
->valid
& PNG_INFO_IDAT
)
1562 png_write_image(png_ptr
, info_ptr
->row_pointers
);
1564 /* It is REQUIRED to call this to finish writing the rest of the file */
1565 png_write_end(png_ptr
, info_ptr
);
1567 PNG_UNUSED(transforms
) /* Quiet compiler warnings */
1573 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
1574 #ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
1575 /* Initialize the write structure - general purpose utility. */
1577 png_image_write_init(png_imagep image
)
1579 png_structp png_ptr
= png_create_write_struct(PNG_LIBPNG_VER_STRING
, image
,
1580 png_safe_error
, png_safe_warning
);
1582 if (png_ptr
!= NULL
)
1584 png_infop info_ptr
= png_create_info_struct(png_ptr
);
1586 if (info_ptr
!= NULL
)
1588 png_controlp control
= png_voidcast(png_controlp
,
1589 png_malloc_warn(png_ptr
, (sizeof *control
)));
1591 if (control
!= NULL
)
1593 memset(control
, 0, (sizeof *control
));
1595 control
->png_ptr
= png_ptr
;
1596 control
->info_ptr
= info_ptr
;
1597 control
->for_write
= 1;
1599 image
->opaque
= control
;
1603 /* Error clean up */
1604 png_destroy_info_struct(png_ptr
, &info_ptr
);
1607 png_destroy_write_struct(&png_ptr
, NULL
);
1610 return png_image_error(image
, "png_image_write_: out of memory");
1613 /* Arguments to png_image_write_main: */
1618 png_const_voidp buffer
;
1619 png_int_32 row_stride
;
1620 png_const_voidp colormap
;
1621 int convert_to_8bit
;
1622 /* Local variables: */
1623 png_const_voidp first_row
;
1624 ptrdiff_t row_bytes
;
1625 png_voidp local_row
;
1626 } png_image_write_control
;
1628 /* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
1629 * do any necessary byte swapping. The component order is defined by the
1630 * png_image format value.
1633 png_write_image_16bit(png_voidp argument
)
1635 png_image_write_control
*display
= png_voidcast(png_image_write_control
*,
1637 png_imagep image
= display
->image
;
1638 png_structrp png_ptr
= image
->opaque
->png_ptr
;
1640 png_const_uint_16p input_row
= png_voidcast(png_const_uint_16p
,
1641 display
->first_row
);
1642 png_uint_16p output_row
= png_voidcast(png_uint_16p
, display
->local_row
);
1643 png_uint_16p row_end
;
1644 const int channels
= (image
->format
& PNG_FORMAT_FLAG_COLOR
) ? 3 : 1;
1646 png_uint_32 y
= image
->height
;
1648 if (image
->format
& PNG_FORMAT_FLAG_ALPHA
)
1650 if (image
->format
& PNG_FORMAT_FLAG_AFIRST
)
1653 ++input_row
; /* To point to the first component */
1662 png_error(png_ptr
, "png_write_image: internal call error");
1664 /* Work out the output row end and count over this, note that the increment
1665 * above to 'row' means that row_end can actually be beyond the end of the
1666 * row; this is correct.
1668 row_end
= output_row
+ image
->width
* (channels
+1);
1672 png_const_uint_16p in_ptr
= input_row
;
1673 png_uint_16p out_ptr
= output_row
;
1675 while (out_ptr
< row_end
)
1677 const png_uint_16 alpha
= in_ptr
[aindex
];
1678 png_uint_32 reciprocal
= 0;
1681 out_ptr
[aindex
] = alpha
;
1683 /* Calculate a reciprocal. The correct calculation is simply
1684 * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
1685 * allows correct rounding by adding .5 before the shift. 'reciprocal'
1686 * is only initialized when required.
1688 if (alpha
> 0 && alpha
< 65535)
1689 reciprocal
= ((0xffff<<15)+(alpha
>>1))/alpha
;
1692 do /* always at least one channel */
1694 png_uint_16 component
= *in_ptr
++;
1696 /* The following gives 65535 for an alpha of 0, which is fine,
1697 * otherwise if 0/0 is represented as some other value there is more
1698 * likely to be a discontinuity which will probably damage
1699 * compression when moving from a fully transparent area to a
1700 * nearly transparent one. (The assumption here is that opaque
1701 * areas tend not to be 0 intensity.)
1703 if (component
>= alpha
)
1706 /* component<alpha, so component/alpha is less than one and
1707 * component*reciprocal is less than 2^31.
1709 else if (component
> 0 && alpha
< 65535)
1711 png_uint_32 calc
= component
* reciprocal
;
1712 calc
+= 16384; /* round to nearest */
1713 component
= (png_uint_16
)(calc
>> 15);
1716 *out_ptr
++ = component
;
1720 /* Skip to next component (skip the intervening alpha channel) */
1725 png_write_row(png_ptr
, png_voidcast(png_const_bytep
, display
->local_row
));
1726 input_row
+= display
->row_bytes
/(sizeof (png_uint_16
));
1732 /* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
1733 * is present it must be removed from the components, the components are then
1734 * written in sRGB encoding. No components are added or removed.
1736 * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
1737 * calculation can be done to 15 bits of accuracy; however, the output needs to
1738 * be scaled in the range 0..255*65535, so include that scaling here.
1740 #define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
1743 png_unpremultiply(png_uint_32 component
, png_uint_32 alpha
,
1744 png_uint_32 reciprocal
/*from the above macro*/)
1746 /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
1747 * is represented as some other value there is more likely to be a
1748 * discontinuity which will probably damage compression when moving from a
1749 * fully transparent area to a nearly transparent one. (The assumption here
1750 * is that opaque areas tend not to be 0 intensity.)
1752 * There is a rounding problem here; if alpha is less than 128 it will end up
1753 * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
1754 * output change for this too.
1756 if (component
>= alpha
|| alpha
< 128)
1759 /* component<alpha, so component/alpha is less than one and
1760 * component*reciprocal is less than 2^31.
1762 else if (component
> 0)
1764 /* The test is that alpha/257 (rounded) is less than 255, the first value
1765 * that becomes 255 is 65407.
1766 * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
1767 * be exact!) [Could also test reciprocal != 0]
1771 component
*= reciprocal
;
1772 component
+= 64; /* round to nearest */
1779 /* Convert the component to sRGB. */
1780 return (png_byte
)PNG_sRGB_FROM_LINEAR(component
);
1788 png_write_image_8bit(png_voidp argument
)
1790 png_image_write_control
*display
= png_voidcast(png_image_write_control
*,
1792 png_imagep image
= display
->image
;
1793 png_structrp png_ptr
= image
->opaque
->png_ptr
;
1795 png_const_uint_16p input_row
= png_voidcast(png_const_uint_16p
,
1796 display
->first_row
);
1797 png_bytep output_row
= png_voidcast(png_bytep
, display
->local_row
);
1798 png_uint_32 y
= image
->height
;
1799 const int channels
= (image
->format
& PNG_FORMAT_FLAG_COLOR
) ? 3 : 1;
1801 if (image
->format
& PNG_FORMAT_FLAG_ALPHA
)
1806 if (image
->format
& PNG_FORMAT_FLAG_AFIRST
)
1809 ++input_row
; /* To point to the first component */
1816 /* Use row_end in place of a loop counter: */
1817 row_end
= output_row
+ image
->width
* (channels
+1);
1821 png_const_uint_16p in_ptr
= input_row
;
1822 png_bytep out_ptr
= output_row
;
1824 while (out_ptr
< row_end
)
1826 png_uint_16 alpha
= in_ptr
[aindex
];
1827 png_byte alphabyte
= (png_byte
)PNG_DIV257(alpha
);
1828 png_uint_32 reciprocal
= 0;
1831 /* Scale and write the alpha channel. */
1832 out_ptr
[aindex
] = alphabyte
;
1834 if (alphabyte
> 0 && alphabyte
< 255)
1835 reciprocal
= UNP_RECIPROCAL(alpha
);
1838 do /* always at least one channel */
1839 *out_ptr
++ = png_unpremultiply(*in_ptr
++, alpha
, reciprocal
);
1842 /* Skip to next component (skip the intervening alpha channel) */
1845 } /* while out_ptr < row_end */
1847 png_write_row(png_ptr
, png_voidcast(png_const_bytep
,
1848 display
->local_row
));
1849 input_row
+= display
->row_bytes
/(sizeof (png_uint_16
));
1855 /* No alpha channel, so the row_end really is the end of the row and it
1856 * is sufficient to loop over the components one by one.
1858 png_bytep row_end
= output_row
+ image
->width
* channels
;
1862 png_const_uint_16p in_ptr
= input_row
;
1863 png_bytep out_ptr
= output_row
;
1865 while (out_ptr
< row_end
)
1867 png_uint_32 component
= *in_ptr
++;
1870 *out_ptr
++ = (png_byte
)PNG_sRGB_FROM_LINEAR(component
);
1873 png_write_row(png_ptr
, output_row
);
1874 input_row
+= display
->row_bytes
/(sizeof (png_uint_16
));
1882 png_image_set_PLTE(png_image_write_control
*display
)
1884 const png_imagep image
= display
->image
;
1885 const void *cmap
= display
->colormap
;
1886 const int entries
= image
->colormap_entries
> 256 ? 256 :
1887 (int)image
->colormap_entries
;
1889 /* NOTE: the caller must check for cmap != NULL and entries != 0 */
1890 const png_uint_32 format
= image
->format
;
1891 const int channels
= PNG_IMAGE_SAMPLE_CHANNELS(format
);
1893 # ifdef PNG_FORMAT_BGR_SUPPORTED
1894 const int afirst
= (format
& PNG_FORMAT_FLAG_AFIRST
) != 0 &&
1895 (format
& PNG_FORMAT_FLAG_ALPHA
) != 0;
1900 # ifdef PNG_FORMAT_BGR_SUPPORTED
1901 const int bgr
= (format
& PNG_FORMAT_FLAG_BGR
) ? 2 : 0;
1907 png_color palette
[256];
1910 memset(tRNS
, 255, (sizeof tRNS
));
1911 memset(palette
, 0, (sizeof palette
));
1913 for (i
=num_trans
=0; i
<entries
; ++i
)
1915 /* This gets automatically converted to sRGB with reversal of the
1916 * pre-multiplication if the color-map has an alpha channel.
1918 if (format
& PNG_FORMAT_FLAG_LINEAR
)
1920 png_const_uint_16p entry
= png_voidcast(png_const_uint_16p
, cmap
);
1922 entry
+= i
* channels
;
1924 if (channels
& 1) /* no alpha */
1926 if (channels
>= 3) /* RGB */
1928 palette
[i
].blue
= (png_byte
)PNG_sRGB_FROM_LINEAR(255 *
1930 palette
[i
].green
= (png_byte
)PNG_sRGB_FROM_LINEAR(255 *
1932 palette
[i
].red
= (png_byte
)PNG_sRGB_FROM_LINEAR(255 *
1937 palette
[i
].blue
= palette
[i
].red
= palette
[i
].green
=
1938 (png_byte
)PNG_sRGB_FROM_LINEAR(255 * *entry
);
1943 png_uint_16 alpha
= entry
[afirst
? 0 : channels
-1];
1944 png_byte alphabyte
= (png_byte
)PNG_DIV257(alpha
);
1945 png_uint_32 reciprocal
= 0;
1947 /* Calculate a reciprocal, as in the png_write_image_8bit code above
1948 * this is designed to produce a value scaled to 255*65535 when
1949 * divided by 128 (i.e. asr 7).
1951 if (alphabyte
> 0 && alphabyte
< 255)
1952 reciprocal
= (((0xffff*0xff)<<7)+(alpha
>>1))/alpha
;
1954 tRNS
[i
] = alphabyte
;
1955 if (alphabyte
< 255)
1958 if (channels
>= 3) /* RGB */
1960 palette
[i
].blue
= png_unpremultiply(entry
[afirst
+ (2 ^ bgr
)],
1962 palette
[i
].green
= png_unpremultiply(entry
[afirst
+ 1], alpha
,
1964 palette
[i
].red
= png_unpremultiply(entry
[afirst
+ bgr
], alpha
,
1969 palette
[i
].blue
= palette
[i
].red
= palette
[i
].green
=
1970 png_unpremultiply(entry
[afirst
], alpha
, reciprocal
);
1974 else /* Color-map has sRGB values */
1976 png_const_bytep entry
= png_voidcast(png_const_bytep
, cmap
);
1978 entry
+= i
* channels
;
1983 tRNS
[i
] = entry
[afirst
? 0 : 3];
1988 palette
[i
].blue
= entry
[afirst
+ (2 ^ bgr
)];
1989 palette
[i
].green
= entry
[afirst
+ 1];
1990 palette
[i
].red
= entry
[afirst
+ bgr
];
1994 tRNS
[i
] = entry
[1 ^ afirst
];
1999 palette
[i
].blue
= palette
[i
].red
= palette
[i
].green
=
2016 png_set_PLTE(image
->opaque
->png_ptr
, image
->opaque
->info_ptr
, palette
,
2020 png_set_tRNS(image
->opaque
->png_ptr
, image
->opaque
->info_ptr
, tRNS
,
2023 image
->colormap_entries
= entries
;
2027 png_image_write_main(png_voidp argument
)
2029 png_image_write_control
*display
= png_voidcast(png_image_write_control
*,
2031 png_imagep image
= display
->image
;
2032 png_structrp png_ptr
= image
->opaque
->png_ptr
;
2033 png_inforp info_ptr
= image
->opaque
->info_ptr
;
2034 png_uint_32 format
= image
->format
;
2036 int colormap
= (format
& PNG_FORMAT_FLAG_COLORMAP
) != 0;
2037 int linear
= !colormap
&& (format
& PNG_FORMAT_FLAG_LINEAR
) != 0; /* input */
2038 int alpha
= !colormap
&& (format
& PNG_FORMAT_FLAG_ALPHA
) != 0;
2039 int write_16bit
= linear
&& !colormap
&& !display
->convert_to_8bit
;
2041 # ifdef PNG_BENIGN_ERRORS_SUPPORTED
2042 /* Make sure we error out on any bad situation */
2043 png_set_benign_errors(png_ptr
, 0/*error*/);
2046 /* Default the 'row_stride' parameter if required. */
2047 if (display
->row_stride
== 0)
2048 display
->row_stride
= PNG_IMAGE_ROW_STRIDE(*image
);
2050 /* Set the required transforms then write the rows in the correct order. */
2051 if (format
& PNG_FORMAT_FLAG_COLORMAP
)
2053 if (display
->colormap
!= NULL
&& image
->colormap_entries
> 0)
2055 png_uint_32 entries
= image
->colormap_entries
;
2057 png_set_IHDR(png_ptr
, info_ptr
, image
->width
, image
->height
,
2058 entries
> 16 ? 8 : (entries
> 4 ? 4 : (entries
> 2 ? 2 : 1)),
2059 PNG_COLOR_TYPE_PALETTE
, PNG_INTERLACE_NONE
,
2060 PNG_COMPRESSION_TYPE_BASE
, PNG_FILTER_TYPE_BASE
);
2062 png_image_set_PLTE(display
);
2066 png_error(image
->opaque
->png_ptr
,
2067 "no color-map for color-mapped image");
2071 png_set_IHDR(png_ptr
, info_ptr
, image
->width
, image
->height
,
2072 write_16bit
? 16 : 8,
2073 ((format
& PNG_FORMAT_FLAG_COLOR
) ? PNG_COLOR_MASK_COLOR
: 0) +
2074 ((format
& PNG_FORMAT_FLAG_ALPHA
) ? PNG_COLOR_MASK_ALPHA
: 0),
2075 PNG_INTERLACE_NONE
, PNG_COMPRESSION_TYPE_BASE
, PNG_FILTER_TYPE_BASE
);
2077 /* Counter-intuitively the data transformations must be called *after*
2078 * png_write_info, not before as in the read code, but the 'set' functions
2079 * must still be called before. Just set the color space information, never
2080 * write an interlaced image.
2085 /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
2086 png_set_gAMA_fixed(png_ptr
, info_ptr
, PNG_GAMMA_LINEAR
);
2088 if (!(image
->flags
& PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB
))
2089 png_set_cHRM_fixed(png_ptr
, info_ptr
,
2091 /* white */ 31270, 32900,
2092 /* red */ 64000, 33000,
2093 /* green */ 30000, 60000,
2094 /* blue */ 15000, 6000
2098 else if (!(image
->flags
& PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB
))
2099 png_set_sRGB(png_ptr
, info_ptr
, PNG_sRGB_INTENT_PERCEPTUAL
);
2101 /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
2102 * space must still be gamma encoded.
2105 png_set_gAMA_fixed(png_ptr
, info_ptr
, PNG_GAMMA_sRGB_INVERSE
);
2107 /* Write the file header. */
2108 png_write_info(png_ptr
, info_ptr
);
2110 /* Now set up the data transformations (*after* the header is written),
2111 * remove the handled transformations from the 'format' flags for checking.
2113 * First check for a little endian system if writing 16 bit files.
2117 PNG_CONST png_uint_16 le
= 0x0001;
2119 if (*(png_const_bytep
)&le
)
2120 png_set_swap(png_ptr
);
2123 # ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
2124 if (format
& PNG_FORMAT_FLAG_BGR
)
2126 if (!colormap
&& (format
& PNG_FORMAT_FLAG_COLOR
) != 0)
2127 png_set_bgr(png_ptr
);
2128 format
&= ~PNG_FORMAT_FLAG_BGR
;
2132 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
2133 if (format
& PNG_FORMAT_FLAG_AFIRST
)
2135 if (!colormap
&& (format
& PNG_FORMAT_FLAG_ALPHA
) != 0)
2136 png_set_swap_alpha(png_ptr
);
2137 format
&= ~PNG_FORMAT_FLAG_AFIRST
;
2141 /* If there are 16 or fewer color-map entries we wrote a lower bit depth
2142 * above, but the application data is still byte packed.
2144 if (colormap
&& image
->colormap_entries
<= 16)
2145 png_set_packing(png_ptr
);
2147 /* That should have handled all (both) the transforms. */
2148 if ((format
& ~(png_uint_32
)(PNG_FORMAT_FLAG_COLOR
| PNG_FORMAT_FLAG_LINEAR
|
2149 PNG_FORMAT_FLAG_ALPHA
| PNG_FORMAT_FLAG_COLORMAP
)) != 0)
2150 png_error(png_ptr
, "png_write_image: unsupported transformation");
2153 png_const_bytep row
= png_voidcast(png_const_bytep
, display
->buffer
);
2154 ptrdiff_t row_bytes
= display
->row_stride
;
2157 row_bytes
*= (sizeof (png_uint_16
));
2160 row
+= (image
->height
-1) * (-row_bytes
);
2162 display
->first_row
= row
;
2163 display
->row_bytes
= row_bytes
;
2166 /* Apply 'fast' options if the flag is set. */
2167 if ((image
->flags
& PNG_IMAGE_FLAG_FAST
) != 0)
2169 png_set_filter(png_ptr
, PNG_FILTER_TYPE_BASE
, PNG_NO_FILTERS
);
2170 /* NOTE: determined by experiment using pngstest, this reflects some
2171 * balance between the time to write the image once and the time to read
2172 * it about 50 times. The speed-up in pngstest was about 10-20% of the
2173 * total (user) time on a heavily loaded system.
2175 png_set_compression_level(png_ptr
, 3);
2178 /* Check for the cases that currently require a pre-transform on the row
2179 * before it is written. This only applies when the input is 16-bit and
2180 * either there is an alpha channel or it is converted to 8-bit.
2182 if ((linear
&& alpha
) || (!colormap
&& display
->convert_to_8bit
))
2184 png_bytep row
= png_voidcast(png_bytep
, png_malloc(png_ptr
,
2185 png_get_rowbytes(png_ptr
, info_ptr
)));
2188 display
->local_row
= row
;
2190 result
= png_safe_execute(image
, png_write_image_16bit
, display
);
2192 result
= png_safe_execute(image
, png_write_image_8bit
, display
);
2193 display
->local_row
= NULL
;
2195 png_free(png_ptr
, row
);
2197 /* Skip the 'write_end' on error: */
2202 /* Otherwise this is the case where the input is in a format currently
2203 * supported by the rest of the libpng write code; call it directly.
2207 png_const_bytep row
= png_voidcast(png_const_bytep
, display
->first_row
);
2208 ptrdiff_t row_bytes
= display
->row_bytes
;
2209 png_uint_32 y
= image
->height
;
2213 png_write_row(png_ptr
, row
);
2218 png_write_end(png_ptr
, info_ptr
);
2223 png_image_write_to_stdio(png_imagep image
, FILE *file
, int convert_to_8bit
,
2224 const void *buffer
, png_int_32 row_stride
, const void *colormap
)
2226 /* Write the image to the given (FILE*). */
2227 if (image
!= NULL
&& image
->version
== PNG_IMAGE_VERSION
)
2231 if (png_image_write_init(image
))
2233 png_image_write_control display
;
2236 /* This is slightly evil, but png_init_io doesn't do anything other
2237 * than this and we haven't changed the standard IO functions so
2238 * this saves a 'safe' function.
2240 image
->opaque
->png_ptr
->io_ptr
= file
;
2242 memset(&display
, 0, (sizeof display
));
2243 display
.image
= image
;
2244 display
.buffer
= buffer
;
2245 display
.row_stride
= row_stride
;
2246 display
.colormap
= colormap
;
2247 display
.convert_to_8bit
= convert_to_8bit
;
2249 result
= png_safe_execute(image
, png_image_write_main
, &display
);
2250 png_image_free(image
);
2259 return png_image_error(image
,
2260 "png_image_write_to_stdio: invalid argument");
2263 else if (image
!= NULL
)
2264 return png_image_error(image
,
2265 "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
2272 png_image_write_to_file(png_imagep image
, const char *file_name
,
2273 int convert_to_8bit
, const void *buffer
, png_int_32 row_stride
,
2274 const void *colormap
)
2276 /* Write the image to the named file. */
2277 if (image
!= NULL
&& image
->version
== PNG_IMAGE_VERSION
)
2279 if (file_name
!= NULL
)
2281 FILE *fp
= fopen(file_name
, "wb");
2285 if (png_image_write_to_stdio(image
, fp
, convert_to_8bit
, buffer
,
2286 row_stride
, colormap
))
2288 int error
; /* from fflush/fclose */
2290 /* Make sure the file is flushed correctly. */
2291 if (fflush(fp
) == 0 && ferror(fp
) == 0)
2293 if (fclose(fp
) == 0)
2296 error
= errno
; /* from fclose */
2301 error
= errno
; /* from fflush or ferror */
2305 (void)remove(file_name
);
2306 /* The image has already been cleaned up; this is just used to
2307 * set the error (because the original write succeeded).
2309 return png_image_error(image
, strerror(error
));
2314 /* Clean up: just the opened file. */
2316 (void)remove(file_name
);
2322 return png_image_error(image
, strerror(errno
));
2326 return png_image_error(image
,
2327 "png_image_write_to_file: invalid argument");
2330 else if (image
!= NULL
)
2331 return png_image_error(image
,
2332 "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
2337 #endif /* PNG_STDIO_SUPPORTED */
2338 #endif /* SIMPLIFIED_WRITE */
2340 #ifdef PNG_WRITE_APNG_SUPPORTED
2342 png_write_frame_head(png_structp png_ptr
, png_infop info_ptr
,
2343 png_bytepp row_pointers
, png_uint_32 width
, png_uint_32 height
,
2344 png_uint_32 x_offset
, png_uint_32 y_offset
,
2345 png_uint_16 delay_num
, png_uint_16 delay_den
, png_byte dispose_op
,
2348 png_debug(1, "in png_write_frame_head");
2350 /* there is a chance this has been set after png_write_info was called,
2351 * so it would be set but not written. is there a way to be sure? */
2352 if (!(info_ptr
->valid
& PNG_INFO_acTL
))
2353 png_error(png_ptr
, "png_write_frame_head(): acTL not set");
2355 png_write_reset(png_ptr
);
2357 png_write_reinit(png_ptr
, info_ptr
, width
, height
);
2359 if ( !(png_ptr
->num_frames_written
== 0 &&
2360 (png_ptr
->apng_flags
& PNG_FIRST_FRAME_HIDDEN
) ) )
2361 png_write_fcTL(png_ptr
, width
, height
, x_offset
, y_offset
,
2362 delay_num
, delay_den
, dispose_op
, blend_op
);
2364 PNG_UNUSED(row_pointers
)
2368 png_write_frame_tail(png_structp png_ptr
, png_infop info_ptr
)
2370 png_debug(1, "in png_write_frame_tail");
2372 png_ptr
->num_frames_written
++;
2374 PNG_UNUSED(info_ptr
)
2376 #endif /* PNG_WRITE_APNG_SUPPORTED */
2377 #endif /* PNG_WRITE_SUPPORTED */