FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
webp.c
Go to the documentation of this file.
1 /*
2  * WebP (.webp) image decoder
3  * Copyright (c) 2013 Aneesh Dogra <aneesh@sugarlabs.org>
4  * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * WebP image decoder
26  *
27  * @author Aneesh Dogra <aneesh@sugarlabs.org>
28  * Container and Lossy decoding
29  *
30  * @author Justin Ruggles <justin.ruggles@gmail.com>
31  * Lossless decoder
32  * Compressed alpha for lossy
33  *
34  * @author James Almer <jamrial@gmail.com>
35  * Exif metadata
36  * ICC profile
37  *
38  * Unimplemented:
39  * - Animation
40  * - XMP metadata
41  */
42 
43 #include "libavutil/imgutils.h"
44 
45 #define BITSTREAM_READER_LE
46 #include "avcodec.h"
47 #include "bytestream.h"
48 #include "exif.h"
49 #include "get_bits.h"
50 #include "internal.h"
51 #include "thread.h"
52 #include "vp8.h"
53 
54 #define VP8X_FLAG_ANIMATION 0x02
55 #define VP8X_FLAG_XMP_METADATA 0x04
56 #define VP8X_FLAG_EXIF_METADATA 0x08
57 #define VP8X_FLAG_ALPHA 0x10
58 #define VP8X_FLAG_ICC 0x20
59 
60 #define MAX_PALETTE_SIZE 256
61 #define MAX_CACHE_BITS 11
62 #define NUM_CODE_LENGTH_CODES 19
63 #define HUFFMAN_CODES_PER_META_CODE 5
64 #define NUM_LITERAL_CODES 256
65 #define NUM_LENGTH_CODES 24
66 #define NUM_DISTANCE_CODES 40
67 #define NUM_SHORT_DISTANCES 120
68 #define MAX_HUFFMAN_CODE_LENGTH 15
69 
70 static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE] = {
74 };
75 
77  17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
78 };
79 
80 static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2] = {
81  { 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 },
82  { 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 },
83  { 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 },
84  { 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 },
85  { 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 },
86  { 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 },
87  { 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 },
88  { 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 },
89  { 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 },
90  { 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 },
91  { 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 },
92  { 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 },
93  { 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 },
94  { -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 },
95  { -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 }
96 };
97 
101 };
102 
108 };
109 
115 };
116 
132 };
133 
140 };
141 
142 /* The structure of WebP lossless is an optional series of transformation data,
143  * followed by the primary image. The primary image also optionally contains
144  * an entropy group mapping if there are multiple entropy groups. There is a
145  * basic image type called an "entropy coded image" that is used for all of
146  * these. The type of each entropy coded image is referred to by the
147  * specification as its role. */
148 enum ImageRole {
149  /* Primary Image: Stores the actual pixels of the image. */
151 
152  /* Entropy Image: Defines which Huffman group to use for different areas of
153  * the primary image. */
155 
156  /* Predictors: Defines which predictor type to use for different areas of
157  * the primary image. */
159 
160  /* Color Transform Data: Defines the color transformation for different
161  * areas of the primary image. */
163 
164  /* Color Index: Stored as an image of height == 1. */
166 
168 };
169 
170 typedef struct HuffReader {
171  VLC vlc; /* Huffman decoder context */
172  int simple; /* whether to use simple mode */
173  int nb_symbols; /* number of coded symbols */
174  uint16_t simple_symbols[2]; /* symbols for simple mode */
175 } HuffReader;
176 
177 typedef struct ImageContext {
178  enum ImageRole role; /* role of this image */
179  AVFrame *frame; /* AVFrame for data */
180  int color_cache_bits; /* color cache size, log2 */
181  uint32_t *color_cache; /* color cache data */
182  int nb_huffman_groups; /* number of huffman groups */
183  HuffReader *huffman_groups; /* reader for each huffman group */
184  int size_reduction; /* relative size compared to primary image, log2 */
186 } ImageContext;
187 
188 typedef struct WebPContext {
189  VP8Context v; /* VP8 Context used for lossy decoding */
190  GetBitContext gb; /* bitstream reader for main image chunk */
191  AVFrame *alpha_frame; /* AVFrame for alpha data decompressed from VP8L */
192  AVCodecContext *avctx; /* parent AVCodecContext */
193  int initialized; /* set once the VP8 context is initialized */
194  int has_alpha; /* has a separate alpha chunk */
195  enum AlphaCompression alpha_compression; /* compression type for alpha chunk */
196  enum AlphaFilter alpha_filter; /* filtering method for alpha chunk */
197  uint8_t *alpha_data; /* alpha chunk data */
198  int alpha_data_size; /* alpha chunk data size */
199  int has_exif; /* set after an EXIF chunk has been processed */
200  int has_iccp; /* set after an ICCP chunk has been processed */
201  int width; /* image width */
202  int height; /* image height */
203  int lossless; /* indicates lossless or lossy */
204 
205  int nb_transforms; /* number of transforms */
206  enum TransformType transforms[4]; /* transformations used in the image, in order */
207  int reduced_width; /* reduced width for index image, if applicable */
208  int nb_huffman_groups; /* number of huffman groups in the primary image */
209  ImageContext image[IMAGE_ROLE_NB]; /* image context for each role */
210 } WebPContext;
211 
212 #define GET_PIXEL(frame, x, y) \
213  ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x))
214 
215 #define GET_PIXEL_COMP(frame, x, y, c) \
216  (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c))
217 
219 {
220  int i, j;
221 
222  av_free(img->color_cache);
223  if (img->role != IMAGE_ROLE_ARGB && !img->is_alpha_primary)
224  av_frame_free(&img->frame);
225  if (img->huffman_groups) {
226  for (i = 0; i < img->nb_huffman_groups; i++) {
227  for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++)
228  ff_free_vlc(&img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE + j].vlc);
229  }
230  av_free(img->huffman_groups);
231  }
232  memset(img, 0, sizeof(*img));
233 }
234 
235 
236 /* Differs from get_vlc2() in the following ways:
237  * - codes are bit-reversed
238  * - assumes 8-bit table to make reversal simpler
239  * - assumes max depth of 2 since the max code length for WebP is 15
240  */
242 {
243  int n, nb_bits;
244  unsigned int index;
245  int code;
246 
247  OPEN_READER(re, gb);
248  UPDATE_CACHE(re, gb);
249 
250  index = SHOW_UBITS(re, gb, 8);
251  index = ff_reverse[index];
252  code = table[index][0];
253  n = table[index][1];
254 
255  if (n < 0) {
256  LAST_SKIP_BITS(re, gb, 8);
257  UPDATE_CACHE(re, gb);
258 
259  nb_bits = -n;
260 
261  index = SHOW_UBITS(re, gb, nb_bits);
262  index = (ff_reverse[index] >> (8 - nb_bits)) + code;
263  code = table[index][0];
264  n = table[index][1];
265  }
266  SKIP_BITS(re, gb, n);
267 
268  CLOSE_READER(re, gb);
269 
270  return code;
271 }
272 
274 {
275  if (r->simple) {
276  if (r->nb_symbols == 1)
277  return r->simple_symbols[0];
278  else
279  return r->simple_symbols[get_bits1(gb)];
280  } else
281  return webp_get_vlc(gb, r->vlc.table);
282 }
283 
284 static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
285  int alphabet_size)
286 {
287  int len = 0, sym, code = 0, ret;
288  int max_code_length = 0;
289  uint16_t *codes;
290 
291  /* special-case 1 symbol since the vlc reader cannot handle it */
292  for (sym = 0; sym < alphabet_size; sym++) {
293  if (code_lengths[sym] > 0) {
294  len++;
295  code = sym;
296  if (len > 1)
297  break;
298  }
299  }
300  if (len == 1) {
301  r->nb_symbols = 1;
302  r->simple_symbols[0] = code;
303  r->simple = 1;
304  return 0;
305  }
306 
307  for (sym = 0; sym < alphabet_size; sym++)
308  max_code_length = FFMAX(max_code_length, code_lengths[sym]);
309 
310  if (max_code_length == 0 || max_code_length > MAX_HUFFMAN_CODE_LENGTH)
311  return AVERROR(EINVAL);
312 
313  codes = av_malloc_array(alphabet_size, sizeof(*codes));
314  if (!codes)
315  return AVERROR(ENOMEM);
316 
317  code = 0;
318  r->nb_symbols = 0;
319  for (len = 1; len <= max_code_length; len++) {
320  for (sym = 0; sym < alphabet_size; sym++) {
321  if (code_lengths[sym] != len)
322  continue;
323  codes[sym] = code++;
324  r->nb_symbols++;
325  }
326  code <<= 1;
327  }
328  if (!r->nb_symbols) {
329  av_free(codes);
330  return AVERROR_INVALIDDATA;
331  }
332 
333  ret = init_vlc(&r->vlc, 8, alphabet_size,
334  code_lengths, sizeof(*code_lengths), sizeof(*code_lengths),
335  codes, sizeof(*codes), sizeof(*codes), 0);
336  if (ret < 0) {
337  av_free(codes);
338  return ret;
339  }
340  r->simple = 0;
341 
342  av_free(codes);
343  return 0;
344 }
345 
347 {
348  hc->nb_symbols = get_bits1(&s->gb) + 1;
349 
350  if (get_bits1(&s->gb))
351  hc->simple_symbols[0] = get_bits(&s->gb, 8);
352  else
353  hc->simple_symbols[0] = get_bits1(&s->gb);
354 
355  if (hc->nb_symbols == 2)
356  hc->simple_symbols[1] = get_bits(&s->gb, 8);
357 
358  hc->simple = 1;
359 }
360 
362  int alphabet_size)
363 {
364  HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
365  int *code_lengths = NULL;
366  int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
367  int i, symbol, max_symbol, prev_code_len, ret;
368  int num_codes = 4 + get_bits(&s->gb, 4);
369 
370  if (num_codes > NUM_CODE_LENGTH_CODES)
371  return AVERROR_INVALIDDATA;
372 
373  for (i = 0; i < num_codes; i++)
374  code_length_code_lengths[code_length_code_order[i]] = get_bits(&s->gb, 3);
375 
376  ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths,
378  if (ret < 0)
379  goto finish;
380 
381  code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths));
382  if (!code_lengths) {
383  ret = AVERROR(ENOMEM);
384  goto finish;
385  }
386 
387  if (get_bits1(&s->gb)) {
388  int bits = 2 + 2 * get_bits(&s->gb, 3);
389  max_symbol = 2 + get_bits(&s->gb, bits);
390  if (max_symbol > alphabet_size) {
391  av_log(s->avctx, AV_LOG_ERROR, "max symbol %d > alphabet size %d\n",
392  max_symbol, alphabet_size);
393  ret = AVERROR_INVALIDDATA;
394  goto finish;
395  }
396  } else {
397  max_symbol = alphabet_size;
398  }
399 
400  prev_code_len = 8;
401  symbol = 0;
402  while (symbol < alphabet_size) {
403  int code_len;
404 
405  if (!max_symbol--)
406  break;
407  code_len = huff_reader_get_symbol(&code_len_hc, &s->gb);
408  if (code_len < 16) {
409  /* Code length code [0..15] indicates literal code lengths. */
410  code_lengths[symbol++] = code_len;
411  if (code_len)
412  prev_code_len = code_len;
413  } else {
414  int repeat = 0, length = 0;
415  switch (code_len) {
416  case 16:
417  /* Code 16 repeats the previous non-zero value [3..6] times,
418  * i.e., 3 + ReadBits(2) times. If code 16 is used before a
419  * non-zero value has been emitted, a value of 8 is repeated. */
420  repeat = 3 + get_bits(&s->gb, 2);
421  length = prev_code_len;
422  break;
423  case 17:
424  /* Code 17 emits a streak of zeros [3..10], i.e.,
425  * 3 + ReadBits(3) times. */
426  repeat = 3 + get_bits(&s->gb, 3);
427  break;
428  case 18:
429  /* Code 18 emits a streak of zeros of length [11..138], i.e.,
430  * 11 + ReadBits(7) times. */
431  repeat = 11 + get_bits(&s->gb, 7);
432  break;
433  }
434  if (symbol + repeat > alphabet_size) {
436  "invalid symbol %d + repeat %d > alphabet size %d\n",
437  symbol, repeat, alphabet_size);
438  ret = AVERROR_INVALIDDATA;
439  goto finish;
440  }
441  while (repeat-- > 0)
442  code_lengths[symbol++] = length;
443  }
444  }
445 
446  ret = huff_reader_build_canonical(hc, code_lengths, alphabet_size);
447 
448 finish:
449  ff_free_vlc(&code_len_hc.vlc);
450  av_free(code_lengths);
451  return ret;
452 }
453 
454 static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
455  int w, int h);
456 
457 #define PARSE_BLOCK_SIZE(w, h) do { \
458  block_bits = get_bits(&s->gb, 3) + 2; \
459  blocks_w = FFALIGN((w), 1 << block_bits) >> block_bits; \
460  blocks_h = FFALIGN((h), 1 << block_bits) >> block_bits; \
461 } while (0)
462 
464 {
465  ImageContext *img;
466  int ret, block_bits, width, blocks_w, blocks_h, x, y, max;
467 
468  width = s->width;
469  if (s->reduced_width > 0)
470  width = s->reduced_width;
471 
472  PARSE_BLOCK_SIZE(width, s->height);
473 
474  ret = decode_entropy_coded_image(s, IMAGE_ROLE_ENTROPY, blocks_w, blocks_h);
475  if (ret < 0)
476  return ret;
477 
478  img = &s->image[IMAGE_ROLE_ENTROPY];
479  img->size_reduction = block_bits;
480 
481  /* the number of huffman groups is determined by the maximum group number
482  * coded in the entropy image */
483  max = 0;
484  for (y = 0; y < img->frame->height; y++) {
485  for (x = 0; x < img->frame->width; x++) {
486  int p0 = GET_PIXEL_COMP(img->frame, x, y, 1);
487  int p1 = GET_PIXEL_COMP(img->frame, x, y, 2);
488  int p = p0 << 8 | p1;
489  max = FFMAX(max, p);
490  }
491  }
492  s->nb_huffman_groups = max + 1;
493 
494  return 0;
495 }
496 
498 {
499  int block_bits, blocks_w, blocks_h, ret;
500 
501  PARSE_BLOCK_SIZE(s->width, s->height);
502 
504  blocks_h);
505  if (ret < 0)
506  return ret;
507 
508  s->image[IMAGE_ROLE_PREDICTOR].size_reduction = block_bits;
509 
510  return 0;
511 }
512 
514 {
515  int block_bits, blocks_w, blocks_h, ret;
516 
517  PARSE_BLOCK_SIZE(s->width, s->height);
518 
520  blocks_h);
521  if (ret < 0)
522  return ret;
523 
525 
526  return 0;
527 }
528 
530 {
531  ImageContext *img;
532  int width_bits, index_size, ret, x;
533  uint8_t *ct;
534 
535  index_size = get_bits(&s->gb, 8) + 1;
536 
537  if (index_size <= 2)
538  width_bits = 3;
539  else if (index_size <= 4)
540  width_bits = 2;
541  else if (index_size <= 16)
542  width_bits = 1;
543  else
544  width_bits = 0;
545 
547  index_size, 1);
548  if (ret < 0)
549  return ret;
550 
551  img = &s->image[IMAGE_ROLE_COLOR_INDEXING];
552  img->size_reduction = width_bits;
553  if (width_bits > 0)
554  s->reduced_width = (s->width + ((1 << width_bits) - 1)) >> width_bits;
555 
556  /* color index values are delta-coded */
557  ct = img->frame->data[0] + 4;
558  for (x = 4; x < img->frame->width * 4; x++, ct++)
559  ct[0] += ct[-4];
560 
561  return 0;
562 }
563 
565  int x, int y)
566 {
568  int group = 0;
569 
570  if (gimg->size_reduction > 0) {
571  int group_x = x >> gimg->size_reduction;
572  int group_y = y >> gimg->size_reduction;
573  int g0 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 1);
574  int g1 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 2);
575  group = g0 << 8 | g1;
576  }
577 
578  return &img->huffman_groups[group * HUFFMAN_CODES_PER_META_CODE];
579 }
580 
582 {
583  uint32_t cache_idx = (0x1E35A7BD * c) >> (32 - img->color_cache_bits);
584  img->color_cache[cache_idx] = c;
585 }
586 
588  int w, int h)
589 {
590  ImageContext *img;
591  HuffReader *hg;
592  int i, j, ret, x, y, width;
593 
594  img = &s->image[role];
595  img->role = role;
596 
597  if (!img->frame) {
598  img->frame = av_frame_alloc();
599  if (!img->frame)
600  return AVERROR(ENOMEM);
601  }
602 
603  img->frame->format = AV_PIX_FMT_ARGB;
604  img->frame->width = w;
605  img->frame->height = h;
606 
607  if (role == IMAGE_ROLE_ARGB && !img->is_alpha_primary) {
608  ThreadFrame pt = { .f = img->frame };
609  ret = ff_thread_get_buffer(s->avctx, &pt, 0);
610  } else
611  ret = av_frame_get_buffer(img->frame, 1);
612  if (ret < 0)
613  return ret;
614 
615  if (get_bits1(&s->gb)) {
616  img->color_cache_bits = get_bits(&s->gb, 4);
617  if (img->color_cache_bits < 1 || img->color_cache_bits > 11) {
618  av_log(s->avctx, AV_LOG_ERROR, "invalid color cache bits: %d\n",
619  img->color_cache_bits);
620  return AVERROR_INVALIDDATA;
621  }
623  sizeof(*img->color_cache));
624  if (!img->color_cache)
625  return AVERROR(ENOMEM);
626  } else {
627  img->color_cache_bits = 0;
628  }
629 
630  img->nb_huffman_groups = 1;
631  if (role == IMAGE_ROLE_ARGB && get_bits1(&s->gb)) {
632  ret = decode_entropy_image(s);
633  if (ret < 0)
634  return ret;
636  }
639  sizeof(*img->huffman_groups));
640  if (!img->huffman_groups)
641  return AVERROR(ENOMEM);
642 
643  for (i = 0; i < img->nb_huffman_groups; i++) {
645  for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) {
646  int alphabet_size = alphabet_sizes[j];
647  if (!j && img->color_cache_bits > 0)
648  alphabet_size += 1 << img->color_cache_bits;
649 
650  if (get_bits1(&s->gb)) {
651  read_huffman_code_simple(s, &hg[j]);
652  } else {
653  ret = read_huffman_code_normal(s, &hg[j], alphabet_size);
654  if (ret < 0)
655  return ret;
656  }
657  }
658  }
659 
660  width = img->frame->width;
661  if (role == IMAGE_ROLE_ARGB && s->reduced_width > 0)
662  width = s->reduced_width;
663 
664  x = 0; y = 0;
665  while (y < img->frame->height) {
666  int v;
667 
668  hg = get_huffman_group(s, img, x, y);
670  if (v < NUM_LITERAL_CODES) {
671  /* literal pixel values */
672  uint8_t *p = GET_PIXEL(img->frame, x, y);
673  p[2] = v;
674  p[1] = huff_reader_get_symbol(&hg[HUFF_IDX_RED], &s->gb);
675  p[3] = huff_reader_get_symbol(&hg[HUFF_IDX_BLUE], &s->gb);
676  p[0] = huff_reader_get_symbol(&hg[HUFF_IDX_ALPHA], &s->gb);
677  if (img->color_cache_bits)
678  color_cache_put(img, AV_RB32(p));
679  x++;
680  if (x == width) {
681  x = 0;
682  y++;
683  }
684  } else if (v < NUM_LITERAL_CODES + NUM_LENGTH_CODES) {
685  /* LZ77 backwards mapping */
686  int prefix_code, length, distance, ref_x, ref_y;
687 
688  /* parse length and distance */
689  prefix_code = v - NUM_LITERAL_CODES;
690  if (prefix_code < 4) {
691  length = prefix_code + 1;
692  } else {
693  int extra_bits = (prefix_code - 2) >> 1;
694  int offset = 2 + (prefix_code & 1) << extra_bits;
695  length = offset + get_bits(&s->gb, extra_bits) + 1;
696  }
697  prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb);
698  if (prefix_code > 39U) {
700  "distance prefix code too large: %d\n", prefix_code);
701  return AVERROR_INVALIDDATA;
702  }
703  if (prefix_code < 4) {
704  distance = prefix_code + 1;
705  } else {
706  int extra_bits = prefix_code - 2 >> 1;
707  int offset = 2 + (prefix_code & 1) << extra_bits;
708  distance = offset + get_bits(&s->gb, extra_bits) + 1;
709  }
710 
711  /* find reference location */
712  if (distance <= NUM_SHORT_DISTANCES) {
713  int xi = lz77_distance_offsets[distance - 1][0];
714  int yi = lz77_distance_offsets[distance - 1][1];
715  distance = FFMAX(1, xi + yi * width);
716  } else {
717  distance -= NUM_SHORT_DISTANCES;
718  }
719  ref_x = x;
720  ref_y = y;
721  if (distance <= x) {
722  ref_x -= distance;
723  distance = 0;
724  } else {
725  ref_x = 0;
726  distance -= x;
727  }
728  while (distance >= width) {
729  ref_y--;
730  distance -= width;
731  }
732  if (distance > 0) {
733  ref_x = width - distance;
734  ref_y--;
735  }
736  ref_x = FFMAX(0, ref_x);
737  ref_y = FFMAX(0, ref_y);
738 
739  /* copy pixels
740  * source and dest regions can overlap and wrap lines, so just
741  * copy per-pixel */
742  for (i = 0; i < length; i++) {
743  uint8_t *p_ref = GET_PIXEL(img->frame, ref_x, ref_y);
744  uint8_t *p = GET_PIXEL(img->frame, x, y);
745 
746  AV_COPY32(p, p_ref);
747  if (img->color_cache_bits)
748  color_cache_put(img, AV_RB32(p));
749  x++;
750  ref_x++;
751  if (x == width) {
752  x = 0;
753  y++;
754  }
755  if (ref_x == width) {
756  ref_x = 0;
757  ref_y++;
758  }
759  if (y == img->frame->height || ref_y == img->frame->height)
760  break;
761  }
762  } else {
763  /* read from color cache */
764  uint8_t *p = GET_PIXEL(img->frame, x, y);
765  int cache_idx = v - (NUM_LITERAL_CODES + NUM_LENGTH_CODES);
766 
767  if (!img->color_cache_bits) {
768  av_log(s->avctx, AV_LOG_ERROR, "color cache not found\n");
769  return AVERROR_INVALIDDATA;
770  }
771  if (cache_idx >= 1 << img->color_cache_bits) {
773  "color cache index out-of-bounds\n");
774  return AVERROR_INVALIDDATA;
775  }
776  AV_WB32(p, img->color_cache[cache_idx]);
777  x++;
778  if (x == width) {
779  x = 0;
780  y++;
781  }
782  }
783  }
784 
785  return 0;
786 }
787 
788 /* PRED_MODE_BLACK */
789 static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
790  const uint8_t *p_t, const uint8_t *p_tr)
791 {
792  AV_WB32(p, 0xFF000000);
793 }
794 
795 /* PRED_MODE_L */
796 static void inv_predict_1(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
797  const uint8_t *p_t, const uint8_t *p_tr)
798 {
799  AV_COPY32(p, p_l);
800 }
801 
802 /* PRED_MODE_T */
803 static void inv_predict_2(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
804  const uint8_t *p_t, const uint8_t *p_tr)
805 {
806  AV_COPY32(p, p_t);
807 }
808 
809 /* PRED_MODE_TR */
810 static void inv_predict_3(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
811  const uint8_t *p_t, const uint8_t *p_tr)
812 {
813  AV_COPY32(p, p_tr);
814 }
815 
816 /* PRED_MODE_TL */
817 static void inv_predict_4(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
818  const uint8_t *p_t, const uint8_t *p_tr)
819 {
820  AV_COPY32(p, p_tl);
821 }
822 
823 /* PRED_MODE_AVG_T_AVG_L_TR */
824 static void inv_predict_5(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
825  const uint8_t *p_t, const uint8_t *p_tr)
826 {
827  p[0] = p_t[0] + (p_l[0] + p_tr[0] >> 1) >> 1;
828  p[1] = p_t[1] + (p_l[1] + p_tr[1] >> 1) >> 1;
829  p[2] = p_t[2] + (p_l[2] + p_tr[2] >> 1) >> 1;
830  p[3] = p_t[3] + (p_l[3] + p_tr[3] >> 1) >> 1;
831 }
832 
833 /* PRED_MODE_AVG_L_TL */
834 static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
835  const uint8_t *p_t, const uint8_t *p_tr)
836 {
837  p[0] = p_l[0] + p_tl[0] >> 1;
838  p[1] = p_l[1] + p_tl[1] >> 1;
839  p[2] = p_l[2] + p_tl[2] >> 1;
840  p[3] = p_l[3] + p_tl[3] >> 1;
841 }
842 
843 /* PRED_MODE_AVG_L_T */
844 static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
845  const uint8_t *p_t, const uint8_t *p_tr)
846 {
847  p[0] = p_l[0] + p_t[0] >> 1;
848  p[1] = p_l[1] + p_t[1] >> 1;
849  p[2] = p_l[2] + p_t[2] >> 1;
850  p[3] = p_l[3] + p_t[3] >> 1;
851 }
852 
853 /* PRED_MODE_AVG_TL_T */
854 static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
855  const uint8_t *p_t, const uint8_t *p_tr)
856 {
857  p[0] = p_tl[0] + p_t[0] >> 1;
858  p[1] = p_tl[1] + p_t[1] >> 1;
859  p[2] = p_tl[2] + p_t[2] >> 1;
860  p[3] = p_tl[3] + p_t[3] >> 1;
861 }
862 
863 /* PRED_MODE_AVG_T_TR */
864 static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
865  const uint8_t *p_t, const uint8_t *p_tr)
866 {
867  p[0] = p_t[0] + p_tr[0] >> 1;
868  p[1] = p_t[1] + p_tr[1] >> 1;
869  p[2] = p_t[2] + p_tr[2] >> 1;
870  p[3] = p_t[3] + p_tr[3] >> 1;
871 }
872 
873 /* PRED_MODE_AVG_AVG_L_TL_AVG_T_TR */
874 static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
875  const uint8_t *p_t, const uint8_t *p_tr)
876 {
877  p[0] = (p_l[0] + p_tl[0] >> 1) + (p_t[0] + p_tr[0] >> 1) >> 1;
878  p[1] = (p_l[1] + p_tl[1] >> 1) + (p_t[1] + p_tr[1] >> 1) >> 1;
879  p[2] = (p_l[2] + p_tl[2] >> 1) + (p_t[2] + p_tr[2] >> 1) >> 1;
880  p[3] = (p_l[3] + p_tl[3] >> 1) + (p_t[3] + p_tr[3] >> 1) >> 1;
881 }
882 
883 /* PRED_MODE_SELECT */
884 static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
885  const uint8_t *p_t, const uint8_t *p_tr)
886 {
887  int diff = (FFABS(p_l[0] - p_tl[0]) - FFABS(p_t[0] - p_tl[0])) +
888  (FFABS(p_l[1] - p_tl[1]) - FFABS(p_t[1] - p_tl[1])) +
889  (FFABS(p_l[2] - p_tl[2]) - FFABS(p_t[2] - p_tl[2])) +
890  (FFABS(p_l[3] - p_tl[3]) - FFABS(p_t[3] - p_tl[3]));
891  if (diff <= 0)
892  AV_COPY32(p, p_t);
893  else
894  AV_COPY32(p, p_l);
895 }
896 
897 /* PRED_MODE_ADD_SUBTRACT_FULL */
898 static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
899  const uint8_t *p_t, const uint8_t *p_tr)
900 {
901  p[0] = av_clip_uint8(p_l[0] + p_t[0] - p_tl[0]);
902  p[1] = av_clip_uint8(p_l[1] + p_t[1] - p_tl[1]);
903  p[2] = av_clip_uint8(p_l[2] + p_t[2] - p_tl[2]);
904  p[3] = av_clip_uint8(p_l[3] + p_t[3] - p_tl[3]);
905 }
906 
908 {
909  int d = a + b >> 1;
910  return av_clip_uint8(d + (d - c) / 2);
911 }
912 
913 /* PRED_MODE_ADD_SUBTRACT_HALF */
914 static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
915  const uint8_t *p_t, const uint8_t *p_tr)
916 {
917  p[0] = clamp_add_subtract_half(p_l[0], p_t[0], p_tl[0]);
918  p[1] = clamp_add_subtract_half(p_l[1], p_t[1], p_tl[1]);
919  p[2] = clamp_add_subtract_half(p_l[2], p_t[2], p_tl[2]);
920  p[3] = clamp_add_subtract_half(p_l[3], p_t[3], p_tl[3]);
921 }
922 
923 typedef void (*inv_predict_func)(uint8_t *p, const uint8_t *p_l,
924  const uint8_t *p_tl, const uint8_t *p_t,
925  const uint8_t *p_tr);
926 
927 static const inv_predict_func inverse_predict[14] = {
932 };
933 
934 static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
935 {
936  uint8_t *dec, *p_l, *p_tl, *p_t, *p_tr;
937  uint8_t p[4];
938 
939  dec = GET_PIXEL(frame, x, y);
940  p_l = GET_PIXEL(frame, x - 1, y);
941  p_tl = GET_PIXEL(frame, x - 1, y - 1);
942  p_t = GET_PIXEL(frame, x, y - 1);
943  if (x == frame->width - 1)
944  p_tr = GET_PIXEL(frame, 0, y);
945  else
946  p_tr = GET_PIXEL(frame, x + 1, y - 1);
947 
948  inverse_predict[m](p, p_l, p_tl, p_t, p_tr);
949 
950  dec[0] += p[0];
951  dec[1] += p[1];
952  dec[2] += p[2];
953  dec[3] += p[3];
954 }
955 
957 {
960  int x, y;
961 
962  for (y = 0; y < img->frame->height; y++) {
963  for (x = 0; x < img->frame->width; x++) {
964  int tx = x >> pimg->size_reduction;
965  int ty = y >> pimg->size_reduction;
966  enum PredictionMode m = GET_PIXEL_COMP(pimg->frame, tx, ty, 2);
967 
968  if (x == 0) {
969  if (y == 0)
970  m = PRED_MODE_BLACK;
971  else
972  m = PRED_MODE_T;
973  } else if (y == 0)
974  m = PRED_MODE_L;
975 
976  if (m > 13) {
978  "invalid predictor mode: %d\n", m);
979  return AVERROR_INVALIDDATA;
980  }
981  inverse_prediction(img->frame, m, x, y);
982  }
983  }
984  return 0;
985 }
986 
988  uint8_t color)
989 {
990  return (int)ff_u8_to_s8(color_pred) * ff_u8_to_s8(color) >> 5;
991 }
992 
994 {
995  ImageContext *img, *cimg;
996  int x, y, cx, cy;
997  uint8_t *p, *cp;
998 
999  img = &s->image[IMAGE_ROLE_ARGB];
1000  cimg = &s->image[IMAGE_ROLE_COLOR_TRANSFORM];
1001 
1002  for (y = 0; y < img->frame->height; y++) {
1003  for (x = 0; x < img->frame->width; x++) {
1004  cx = x >> cimg->size_reduction;
1005  cy = y >> cimg->size_reduction;
1006  cp = GET_PIXEL(cimg->frame, cx, cy);
1007  p = GET_PIXEL(img->frame, x, y);
1008 
1009  p[1] += color_transform_delta(cp[3], p[2]);
1010  p[3] += color_transform_delta(cp[2], p[2]) +
1011  color_transform_delta(cp[1], p[1]);
1012  }
1013  }
1014  return 0;
1015 }
1016 
1018 {
1019  int x, y;
1021 
1022  for (y = 0; y < img->frame->height; y++) {
1023  for (x = 0; x < img->frame->width; x++) {
1024  uint8_t *p = GET_PIXEL(img->frame, x, y);
1025  p[1] += p[2];
1026  p[3] += p[2];
1027  }
1028  }
1029  return 0;
1030 }
1031 
1033 {
1034  ImageContext *img;
1035  ImageContext *pal;
1036  int i, x, y;
1037  uint8_t *p;
1038 
1039  img = &s->image[IMAGE_ROLE_ARGB];
1040  pal = &s->image[IMAGE_ROLE_COLOR_INDEXING];
1041 
1042  if (pal->size_reduction > 0) {
1043  GetBitContext gb_g;
1044  uint8_t *line;
1045  int pixel_bits = 8 >> pal->size_reduction;
1046 
1048  if (!line)
1049  return AVERROR(ENOMEM);
1050 
1051  for (y = 0; y < img->frame->height; y++) {
1052  p = GET_PIXEL(img->frame, 0, y);
1053  memcpy(line, p, img->frame->linesize[0]);
1054  init_get_bits(&gb_g, line, img->frame->linesize[0] * 8);
1055  skip_bits(&gb_g, 16);
1056  i = 0;
1057  for (x = 0; x < img->frame->width; x++) {
1058  p = GET_PIXEL(img->frame, x, y);
1059  p[2] = get_bits(&gb_g, pixel_bits);
1060  i++;
1061  if (i == 1 << pal->size_reduction) {
1062  skip_bits(&gb_g, 24);
1063  i = 0;
1064  }
1065  }
1066  }
1067  av_free(line);
1068  }
1069 
1070  // switch to local palette if it's worth initializing it
1071  if (img->frame->height * img->frame->width > 300) {
1072  uint8_t palette[256 * 4];
1073  const int size = pal->frame->width * 4;
1074  av_assert0(size <= 1024U);
1075  memcpy(palette, GET_PIXEL(pal->frame, 0, 0), size); // copy palette
1076  // set extra entries to transparent black
1077  memset(palette + size, 0, 256 * 4 - size);
1078  for (y = 0; y < img->frame->height; y++) {
1079  for (x = 0; x < img->frame->width; x++) {
1080  p = GET_PIXEL(img->frame, x, y);
1081  i = p[2];
1082  AV_COPY32(p, &palette[i * 4]);
1083  }
1084  }
1085  } else {
1086  for (y = 0; y < img->frame->height; y++) {
1087  for (x = 0; x < img->frame->width; x++) {
1088  p = GET_PIXEL(img->frame, x, y);
1089  i = p[2];
1090  if (i >= pal->frame->width) {
1091  AV_WB32(p, 0x00000000);
1092  } else {
1093  const uint8_t *pi = GET_PIXEL(pal->frame, i, 0);
1094  AV_COPY32(p, pi);
1095  }
1096  }
1097  }
1098  }
1099 
1100  return 0;
1101 }
1102 
1103 static void update_canvas_size(AVCodecContext *avctx, int w, int h)
1104 {
1105  WebPContext *s = avctx->priv_data;
1106  if (s->width && s->width != w) {
1107  av_log(avctx, AV_LOG_WARNING, "Width mismatch. %d != %d\n",
1108  s->width, w);
1109  }
1110  s->width = w;
1111  if (s->height && s->height != h) {
1112  av_log(avctx, AV_LOG_WARNING, "Height mismatch. %d != %d\n",
1113  s->height, h);
1114  }
1115  s->height = h;
1116 }
1117 
1119  int *got_frame, uint8_t *data_start,
1120  unsigned int data_size, int is_alpha_chunk)
1121 {
1122  WebPContext *s = avctx->priv_data;
1123  int w, h, ret, i, used;
1124 
1125  if (!is_alpha_chunk) {
1126  s->lossless = 1;
1127  avctx->pix_fmt = AV_PIX_FMT_ARGB;
1128  }
1129 
1130  ret = init_get_bits8(&s->gb, data_start, data_size);
1131  if (ret < 0)
1132  return ret;
1133 
1134  if (!is_alpha_chunk) {
1135  if (get_bits(&s->gb, 8) != 0x2F) {
1136  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless signature\n");
1137  return AVERROR_INVALIDDATA;
1138  }
1139 
1140  w = get_bits(&s->gb, 14) + 1;
1141  h = get_bits(&s->gb, 14) + 1;
1142 
1143  update_canvas_size(avctx, w, h);
1144 
1145  ret = ff_set_dimensions(avctx, s->width, s->height);
1146  if (ret < 0)
1147  return ret;
1148 
1149  s->has_alpha = get_bits1(&s->gb);
1150 
1151  if (get_bits(&s->gb, 3) != 0x0) {
1152  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless version\n");
1153  return AVERROR_INVALIDDATA;
1154  }
1155  } else {
1156  if (!s->width || !s->height)
1157  return AVERROR_BUG;
1158  w = s->width;
1159  h = s->height;
1160  }
1161 
1162  /* parse transformations */
1163  s->nb_transforms = 0;
1164  s->reduced_width = 0;
1165  used = 0;
1166  while (get_bits1(&s->gb)) {
1167  enum TransformType transform = get_bits(&s->gb, 2);
1168  if (used & (1 << transform)) {
1169  av_log(avctx, AV_LOG_ERROR, "Transform %d used more than once\n",
1170  transform);
1171  ret = AVERROR_INVALIDDATA;
1172  goto free_and_return;
1173  }
1174  used |= (1 << transform);
1175  s->transforms[s->nb_transforms++] = transform;
1176  switch (transform) {
1177  case PREDICTOR_TRANSFORM:
1178  ret = parse_transform_predictor(s);
1179  break;
1180  case COLOR_TRANSFORM:
1181  ret = parse_transform_color(s);
1182  break;
1185  break;
1186  }
1187  if (ret < 0)
1188  goto free_and_return;
1189  }
1190 
1191  /* decode primary image */
1192  s->image[IMAGE_ROLE_ARGB].frame = p;
1193  if (is_alpha_chunk)
1196  if (ret < 0)
1197  goto free_and_return;
1198 
1199  /* apply transformations */
1200  for (i = s->nb_transforms - 1; i >= 0; i--) {
1201  switch (s->transforms[i]) {
1202  case PREDICTOR_TRANSFORM:
1203  ret = apply_predictor_transform(s);
1204  break;
1205  case COLOR_TRANSFORM:
1206  ret = apply_color_transform(s);
1207  break;
1208  case SUBTRACT_GREEN:
1210  break;
1213  break;
1214  }
1215  if (ret < 0)
1216  goto free_and_return;
1217  }
1218 
1219  *got_frame = 1;
1221  p->key_frame = 1;
1222  ret = data_size;
1223 
1224 free_and_return:
1225  for (i = 0; i < IMAGE_ROLE_NB; i++)
1226  image_ctx_free(&s->image[i]);
1227 
1228  return ret;
1229 }
1230 
1232 {
1233  int x, y, ls;
1234  uint8_t *dec;
1235 
1236  ls = frame->linesize[3];
1237 
1238  /* filter first row using horizontal filter */
1239  dec = frame->data[3] + 1;
1240  for (x = 1; x < frame->width; x++, dec++)
1241  *dec += *(dec - 1);
1242 
1243  /* filter first column using vertical filter */
1244  dec = frame->data[3] + ls;
1245  for (y = 1; y < frame->height; y++, dec += ls)
1246  *dec += *(dec - ls);
1247 
1248  /* filter the rest using the specified filter */
1249  switch (m) {
1251  for (y = 1; y < frame->height; y++) {
1252  dec = frame->data[3] + y * ls + 1;
1253  for (x = 1; x < frame->width; x++, dec++)
1254  *dec += *(dec - 1);
1255  }
1256  break;
1257  case ALPHA_FILTER_VERTICAL:
1258  for (y = 1; y < frame->height; y++) {
1259  dec = frame->data[3] + y * ls + 1;
1260  for (x = 1; x < frame->width; x++, dec++)
1261  *dec += *(dec - ls);
1262  }
1263  break;
1264  case ALPHA_FILTER_GRADIENT:
1265  for (y = 1; y < frame->height; y++) {
1266  dec = frame->data[3] + y * ls + 1;
1267  for (x = 1; x < frame->width; x++, dec++)
1268  dec[0] += av_clip_uint8(*(dec - 1) + *(dec - ls) - *(dec - ls - 1));
1269  }
1270  break;
1271  }
1272 }
1273 
1275  uint8_t *data_start,
1276  unsigned int data_size)
1277 {
1278  WebPContext *s = avctx->priv_data;
1279  int x, y, ret;
1280 
1282  GetByteContext gb;
1283 
1284  bytestream2_init(&gb, data_start, data_size);
1285  for (y = 0; y < s->height; y++)
1286  bytestream2_get_buffer(&gb, p->data[3] + p->linesize[3] * y,
1287  s->width);
1288  } else if (s->alpha_compression == ALPHA_COMPRESSION_VP8L) {
1289  uint8_t *ap, *pp;
1290  int alpha_got_frame = 0;
1291 
1292  s->alpha_frame = av_frame_alloc();
1293  if (!s->alpha_frame)
1294  return AVERROR(ENOMEM);
1295 
1296  ret = vp8_lossless_decode_frame(avctx, s->alpha_frame, &alpha_got_frame,
1297  data_start, data_size, 1);
1298  if (ret < 0) {
1300  return ret;
1301  }
1302  if (!alpha_got_frame) {
1304  return AVERROR_INVALIDDATA;
1305  }
1306 
1307  /* copy green component of alpha image to alpha plane of primary image */
1308  for (y = 0; y < s->height; y++) {
1309  ap = GET_PIXEL(s->alpha_frame, 0, y) + 2;
1310  pp = p->data[3] + p->linesize[3] * y;
1311  for (x = 0; x < s->width; x++) {
1312  *pp = *ap;
1313  pp++;
1314  ap += 4;
1315  }
1316  }
1318  }
1319 
1320  /* apply alpha filtering */
1321  if (s->alpha_filter)
1323 
1324  return 0;
1325 }
1326 
1328  int *got_frame, uint8_t *data_start,
1329  unsigned int data_size)
1330 {
1331  WebPContext *s = avctx->priv_data;
1332  AVPacket pkt;
1333  int ret;
1334 
1335  if (!s->initialized) {
1336  ff_vp8_decode_init(avctx);
1337  s->initialized = 1;
1338  s->v.actually_webp = 1;
1339  }
1341  s->lossless = 0;
1342 
1343  if (data_size > INT_MAX) {
1344  av_log(avctx, AV_LOG_ERROR, "unsupported chunk size\n");
1345  return AVERROR_PATCHWELCOME;
1346  }
1347 
1348  av_init_packet(&pkt);
1349  pkt.data = data_start;
1350  pkt.size = data_size;
1351 
1352  ret = ff_vp8_decode_frame(avctx, p, got_frame, &pkt);
1353  if (ret < 0)
1354  return ret;
1355 
1356  if (!*got_frame)
1357  return AVERROR_INVALIDDATA;
1358 
1359  update_canvas_size(avctx, avctx->width, avctx->height);
1360 
1361  if (s->has_alpha) {
1362  ret = vp8_lossy_decode_alpha(avctx, p, s->alpha_data,
1363  s->alpha_data_size);
1364  if (ret < 0)
1365  return ret;
1366  }
1367  return ret;
1368 }
1369 
1370 static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
1371  AVPacket *avpkt)
1372 {
1373  AVFrame * const p = data;
1374  WebPContext *s = avctx->priv_data;
1375  GetByteContext gb;
1376  int ret;
1377  uint32_t chunk_type, chunk_size;
1378  int vp8x_flags = 0;
1379 
1380  s->avctx = avctx;
1381  s->width = 0;
1382  s->height = 0;
1383  *got_frame = 0;
1384  s->has_alpha = 0;
1385  s->has_exif = 0;
1386  s->has_iccp = 0;
1387  bytestream2_init(&gb, avpkt->data, avpkt->size);
1388 
1389  if (bytestream2_get_bytes_left(&gb) < 12)
1390  return AVERROR_INVALIDDATA;
1391 
1392  if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
1393  av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
1394  return AVERROR_INVALIDDATA;
1395  }
1396 
1397  chunk_size = bytestream2_get_le32(&gb);
1398  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1399  return AVERROR_INVALIDDATA;
1400 
1401  if (bytestream2_get_le32(&gb) != MKTAG('W', 'E', 'B', 'P')) {
1402  av_log(avctx, AV_LOG_ERROR, "missing WEBP tag\n");
1403  return AVERROR_INVALIDDATA;
1404  }
1405 
1406  while (bytestream2_get_bytes_left(&gb) > 8) {
1407  char chunk_str[5] = { 0 };
1408 
1409  chunk_type = bytestream2_get_le32(&gb);
1410  chunk_size = bytestream2_get_le32(&gb);
1411  if (chunk_size == UINT32_MAX)
1412  return AVERROR_INVALIDDATA;
1413  chunk_size += chunk_size & 1;
1414 
1415  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1416  return AVERROR_INVALIDDATA;
1417 
1418  switch (chunk_type) {
1419  case MKTAG('V', 'P', '8', ' '):
1420  if (!*got_frame) {
1421  ret = vp8_lossy_decode_frame(avctx, p, got_frame,
1422  avpkt->data + bytestream2_tell(&gb),
1423  chunk_size);
1424  if (ret < 0)
1425  return ret;
1426  }
1427  bytestream2_skip(&gb, chunk_size);
1428  break;
1429  case MKTAG('V', 'P', '8', 'L'):
1430  if (!*got_frame) {
1431  ret = vp8_lossless_decode_frame(avctx, p, got_frame,
1432  avpkt->data + bytestream2_tell(&gb),
1433  chunk_size, 0);
1434  if (ret < 0)
1435  return ret;
1437  }
1438  bytestream2_skip(&gb, chunk_size);
1439  break;
1440  case MKTAG('V', 'P', '8', 'X'):
1441  if (s->width || s->height || *got_frame) {
1442  av_log(avctx, AV_LOG_ERROR, "Canvas dimensions are already set\n");
1443  return AVERROR_INVALIDDATA;
1444  }
1445  vp8x_flags = bytestream2_get_byte(&gb);
1446  bytestream2_skip(&gb, 3);
1447  s->width = bytestream2_get_le24(&gb) + 1;
1448  s->height = bytestream2_get_le24(&gb) + 1;
1449  ret = av_image_check_size(s->width, s->height, 0, avctx);
1450  if (ret < 0)
1451  return ret;
1452  break;
1453  case MKTAG('A', 'L', 'P', 'H'): {
1454  int alpha_header, filter_m, compression;
1455 
1456  if (!(vp8x_flags & VP8X_FLAG_ALPHA)) {
1457  av_log(avctx, AV_LOG_WARNING,
1458  "ALPHA chunk present, but alpha bit not set in the "
1459  "VP8X header\n");
1460  }
1461  if (chunk_size == 0) {
1462  av_log(avctx, AV_LOG_ERROR, "invalid ALPHA chunk size\n");
1463  return AVERROR_INVALIDDATA;
1464  }
1465  alpha_header = bytestream2_get_byte(&gb);
1466  s->alpha_data = avpkt->data + bytestream2_tell(&gb);
1467  s->alpha_data_size = chunk_size - 1;
1469 
1470  filter_m = (alpha_header >> 2) & 0x03;
1471  compression = alpha_header & 0x03;
1472 
1473  if (compression > ALPHA_COMPRESSION_VP8L) {
1474  av_log(avctx, AV_LOG_VERBOSE,
1475  "skipping unsupported ALPHA chunk\n");
1476  } else {
1477  s->has_alpha = 1;
1478  s->alpha_compression = compression;
1479  s->alpha_filter = filter_m;
1480  }
1481 
1482  break;
1483  }
1484  case MKTAG('E', 'X', 'I', 'F'): {
1485  int le, ifd_offset, exif_offset = bytestream2_tell(&gb);
1486  AVDictionary *exif_metadata = NULL;
1487  GetByteContext exif_gb;
1488 
1489  if (s->has_exif) {
1490  av_log(avctx, AV_LOG_VERBOSE, "Ignoring extra EXIF chunk\n");
1491  goto exif_end;
1492  }
1493  if (!(vp8x_flags & VP8X_FLAG_EXIF_METADATA))
1494  av_log(avctx, AV_LOG_WARNING,
1495  "EXIF chunk present, but Exif bit not set in the "
1496  "VP8X header\n");
1497 
1498  s->has_exif = 1;
1499  bytestream2_init(&exif_gb, avpkt->data + exif_offset,
1500  avpkt->size - exif_offset);
1501  if (ff_tdecode_header(&exif_gb, &le, &ifd_offset) < 0) {
1502  av_log(avctx, AV_LOG_ERROR, "invalid TIFF header "
1503  "in Exif data\n");
1504  goto exif_end;
1505  }
1506 
1507  bytestream2_seek(&exif_gb, ifd_offset, SEEK_SET);
1508  if (ff_exif_decode_ifd(avctx, &exif_gb, le, 0, &exif_metadata) < 0) {
1509  av_log(avctx, AV_LOG_ERROR, "error decoding Exif data\n");
1510  goto exif_end;
1511  }
1512 
1513  av_dict_copy(&((AVFrame *) data)->metadata, exif_metadata, 0);
1514 
1515 exif_end:
1516  av_dict_free(&exif_metadata);
1517  bytestream2_skip(&gb, chunk_size);
1518  break;
1519  }
1520  case MKTAG('I', 'C', 'C', 'P'): {
1521  AVFrameSideData *sd;
1522 
1523  if (s->has_iccp) {
1524  av_log(avctx, AV_LOG_VERBOSE, "Ignoring extra ICCP chunk\n");
1525  bytestream2_skip(&gb, chunk_size);
1526  break;
1527  }
1528  if (!(vp8x_flags & VP8X_FLAG_ICC))
1529  av_log(avctx, AV_LOG_WARNING,
1530  "ICCP chunk present, but ICC Profile bit not set in the "
1531  "VP8X header\n");
1532 
1533  s->has_iccp = 1;
1535  if (!sd)
1536  return AVERROR(ENOMEM);
1537 
1538  bytestream2_get_buffer(&gb, sd->data, chunk_size);
1539  break;
1540  }
1541  case MKTAG('A', 'N', 'I', 'M'):
1542  case MKTAG('A', 'N', 'M', 'F'):
1543  case MKTAG('X', 'M', 'P', ' '):
1544  AV_WL32(chunk_str, chunk_type);
1545  av_log(avctx, AV_LOG_WARNING, "skipping unsupported chunk: %s\n",
1546  chunk_str);
1547  bytestream2_skip(&gb, chunk_size);
1548  break;
1549  default:
1550  AV_WL32(chunk_str, chunk_type);
1551  av_log(avctx, AV_LOG_VERBOSE, "skipping unknown chunk: %s\n",
1552  chunk_str);
1553  bytestream2_skip(&gb, chunk_size);
1554  break;
1555  }
1556  }
1557 
1558  if (!*got_frame) {
1559  av_log(avctx, AV_LOG_ERROR, "image data not found\n");
1560  return AVERROR_INVALIDDATA;
1561  }
1562 
1563  return avpkt->size;
1564 }
1565 
1567 {
1568  WebPContext *s = avctx->priv_data;
1569 
1570  if (s->initialized)
1571  return ff_vp8_decode_free(avctx);
1572 
1573  return 0;
1574 }
1575 
1577  .name = "webp",
1578  .long_name = NULL_IF_CONFIG_SMALL("WebP image"),
1579  .type = AVMEDIA_TYPE_VIDEO,
1580  .id = AV_CODEC_ID_WEBP,
1581  .priv_data_size = sizeof(WebPContext),
1583  .close = webp_decode_close,
1584  .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
1585 };
int nb_huffman_groups
Definition: webp.c:182
#define extra_bits(eb)
Definition: intrax8.c:159
static int read_huffman_code_normal(WebPContext *s, HuffReader *hc, int alphabet_size)
Definition: webp.c:361
enum ImageRole role
Definition: webp.c:178
#define NULL
Definition: coverity.c:32
HuffReader * huffman_groups
Definition: webp.c:183
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
int ff_exif_decode_ifd(void *logctx, GetByteContext *gbytes, int le, int depth, AVDictionary **metadata)
Definition: exif.c:122
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
TransformType
Definition: webp.c:110
static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:874
float re
Definition: fft.c:82
ImageRole
Definition: webp.c:148
misc image utilities
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:261
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:196
int initialized
Definition: webp.c:193
static int parse_transform_color_indexing(WebPContext *s)
Definition: webp.c:529
const uint8_t ff_reverse[256]
Definition: reverse.c:23
static HuffReader * get_huffman_group(WebPContext *s, ImageContext *img, int x, int y)
Definition: webp.c:564
HuffmanIndex
Definition: webp.c:134
static const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES]
Definition: webp.c:76
int size
Definition: avcodec.h:1415
const char * b
Definition: vf_curves.c:113
#define VP8X_FLAG_EXIF_METADATA
Definition: webp.c:56
static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:884
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1711
static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
Definition: webp.c:273
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:217
GetBitContext gb
Definition: webp.c:190
static int8_t ff_u8_to_s8(uint8_t a)
Definition: mathops.h:233
static const inv_predict_func inverse_predict[14]
Definition: webp.c:927
static AVPacket pkt
static int apply_color_indexing_transform(WebPContext *s)
Definition: webp.c:1032
AVCodec.
Definition: avcodec.h:3365
EXIF metadata parser.
#define AV_COPY32(d, s)
Definition: intreadwrite.h:586
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
AlphaCompression
Definition: webp.c:98
static av_always_inline uint8_t clamp_add_subtract_half(int a, int b, int c)
Definition: webp.c:907
enum TransformType transforms[4]
Definition: webp.c:206
uint16_t simple_symbols[2]
Definition: webp.c:174
int height
Definition: webp.c:202
static int vp8_lossy_decode_alpha(AVCodecContext *avctx, AVFrame *p, uint8_t *data_start, unsigned int data_size)
Definition: webp.c:1274
#define NUM_LITERAL_CODES
Definition: webp.c:64
#define img
static av_always_inline void color_cache_put(ImageContext *img, uint32_t c)
Definition: webp.c:581
enum AlphaFilter alpha_filter
Definition: webp.c:196
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:864
uint8_t * alpha_data
Definition: webp.c:197
#define NUM_CODE_LENGTH_CODES
Definition: webp.c:62
int reduced_width
Definition: webp.c:207
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:97
int nb_huffman_groups
Definition: webp.c:208
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:150
int nb_symbols
Definition: webp.c:173
Multithreading support functions.
int ff_vp8_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: vp8.c:2788
#define FF_CODEC_PROPERTY_LOSSLESS
Definition: avcodec.h:3134
int simple
Definition: webp.c:172
static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:898
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
static AVFrame * frame
Structure to hold side data for an AVFrame.
Definition: frame.h:163
#define NUM_SHORT_DISTANCES
Definition: webp.c:67
int pt
Definition: rtp.c:35
static void finish(void)
Definition: movenc.c:345
uint8_t * data
Definition: avcodec.h:1414
#define VP8X_FLAG_ICC
Definition: webp.c:58
bitstream reader API header.
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
static int decode_entropy_image(WebPContext *s)
Definition: webp.c:463
ptrdiff_t size
Definition: opengl_enc.c:101
#define av_log(a,...)
static void inv_predict_1(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:796
#define U(x)
Definition: vp56_arith.h:37
static int apply_color_transform(WebPContext *s)
Definition: webp.c:993
#define VP8X_FLAG_ALPHA
Definition: webp.c:57
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:160
int width
Definition: frame.h:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: webp.c:1370
static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:834
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: vlc.h:38
#define AVERROR(e)
Definition: error.h:43
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:163
static const struct endianess table[]
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * r
Definition: vf_curves.c:111
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:203
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
Definition: graph2dot.c:48
uint16_t width
Definition: gdv.c:47
GLsizei GLsizei * length
Definition: opengl_enc.c:115
const char * name
Name of the codec implementation.
Definition: avcodec.h:3372
static void inv_predict_3(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:810
int has_exif
Definition: webp.c:199
VP8Context v
Definition: webp.c:189
static int vp8_lossy_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, uint8_t *data_start, unsigned int data_size)
Definition: webp.c:1327
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
#define CLOSE_READER(name, gb)
Definition: get_bits.h:131
#define FFMAX(a, b)
Definition: common.h:94
static int vp8_lossless_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, uint8_t *data_start, unsigned int data_size, int is_alpha_chunk)
Definition: webp.c:1118
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:88
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: avcodec.h:1012
enum AlphaCompression alpha_compression
Definition: webp.c:195
static void image_ctx_free(ImageContext *img)
Definition: webp.c:218
Definition: vlc.h:26
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:175
static float distance(float x, float y, int band)
static av_always_inline int webp_get_vlc(GetBitContext *gb, VLC_TYPE(*table)[2])
Definition: webp.c:241
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:282
#define PARSE_BLOCK_SIZE(w, h)
Definition: webp.c:457
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:284
static void inv_predict_2(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:803
int has_iccp
Definition: webp.c:200
int width
picture width / height.
Definition: avcodec.h:1674
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
uint32_t * color_cache
Definition: webp.c:181
AlphaFilter
Definition: webp.c:103
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
AVFrame * frame
Definition: webp.c:179
The data contains an ICC profile as an opaque octet buffer following the format described by ISO 1507...
Definition: frame.h:143
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:181
int n
Definition: avisynth_c.h:684
int has_alpha
Definition: webp.c:194
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:193
void(* inv_predict_func)(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:923
PredictionMode
Definition: webp.c:117
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:188
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:274
static const int8_t transform[32][32]
Definition: hevcdsp.c:27
int alpha_data_size
Definition: webp.c:198
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:232
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:456
int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
Wrapper around get_buffer() for frame-multithreaded codecs.
static int huff_reader_build_canonical(HuffReader *r, int *code_lengths, int alphabet_size)
Definition: webp.c:284
main external API structure.
Definition: avcodec.h:1502
#define OPEN_READER(name, gb)
Definition: get_bits.h:120
uint8_t * data
Definition: frame.h:165
#define AVERROR_BUG
Internal bug, also see AVERROR_BUG2.
Definition: error.h:50
static av_always_inline uint8_t color_transform_delta(uint8_t color_pred, uint8_t color)
Definition: webp.c:987
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:313
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:306
AVFrameSideData * av_frame_new_side_data(AVFrame *frame, enum AVFrameSideDataType type, int size)
Add a new side data to a frame.
Definition: frame.c:680
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
int index
Definition: gxfenc.c:89
AVCodec ff_webp_decoder
Definition: webp.c:1576
static void inv_predict_4(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:817
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:425
static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:789
#define MAX_HUFFMAN_CODE_LENGTH
Definition: webp.c:68
int size_reduction
Definition: webp.c:184
int actually_webp
Definition: vp8.h:151
static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE]
Definition: webp.c:70
#define HUFFMAN_CODES_PER_META_CODE
Definition: webp.c:63
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
Definition: frame.c:283
static void read_huffman_code_simple(WebPContext *s, HuffReader *hc)
Definition: webp.c:346
av_cold int ff_vp8_decode_init(AVCodecContext *avctx)
Definition: vp8.c:2873
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:215
av_cold int ff_vp8_decode_free(AVCodecContext *avctx)
Definition: vp8.c:2802
static int parse_transform_predictor(WebPContext *s)
Definition: webp.c:497
#define GET_PIXEL(frame, x, y)
Definition: webp.c:212
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:62
static av_cold int webp_decode_close(AVCodecContext *avctx)
Definition: webp.c:1566
int nb_transforms
Definition: webp.c:205
common internal api header.
static int apply_subtract_green_transform(WebPContext *s)
Definition: webp.c:1017
static double c[64]
int is_alpha_primary
Definition: webp.c:185
#define GET_PIXEL_COMP(frame, x, y, c)
Definition: webp.c:215
static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:854
unsigned properties
Properties of the stream that gets decoded.
Definition: avcodec.h:3133
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:33
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:770
void * priv_data
Definition: avcodec.h:1529
static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2]
Definition: webp.c:80
ImageContext image[IMAGE_ROLE_NB]
Definition: webp.c:209
int width
Definition: webp.c:201
static av_always_inline int diff(const uint32_t a, const uint32_t b)
static int apply_predictor_transform(WebPContext *s)
Definition: webp.c:956
#define av_free(p)
VLC vlc
Definition: webp.c:171
int len
int color_cache_bits
Definition: webp.c:180
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
static int parse_transform_color(WebPContext *s)
Definition: webp.c:513
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:279
static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:844
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence)
Definition: bytestream.h:208
static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role, int w, int h)
Definition: webp.c:587
static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:914
int ff_tdecode_header(GetByteContext *gb, int *le, int *ifd_offset)
Decodes a TIFF header from the input bytestream and sets the endianness in *le and the offset to the ...
Definition: tiff_common.c:261
AVCodecContext * avctx
Definition: webp.c:192
int height
Definition: frame.h:259
static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
Definition: webp.c:1231
#define av_always_inline
Definition: attributes.h:39
#define VLC_TYPE
Definition: vlc.h:24
#define av_malloc_array(a, b)
int lossless
Definition: webp.c:203
static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
Definition: webp.c:934
#define MKTAG(a, b, c, d)
Definition: common.h:366
This structure stores compressed data.
Definition: avcodec.h:1391
AVFrame * alpha_frame
Definition: webp.c:191
static void update_canvas_size(AVCodecContext *avctx, int w, int h)
Definition: webp.c:1103
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:354
static void inv_predict_5(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:824
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956
#define NUM_LENGTH_CODES
Definition: webp.c:65
#define NUM_DISTANCE_CODES
Definition: webp.c:66
#define AV_WL32(p, v)
Definition: intreadwrite.h:426
void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.c:191