Libav
webp.c
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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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
40 #define BITSTREAM_READER_LE
41 #include "libavutil/imgutils.h"
42 #include "avcodec.h"
43 #include "bytestream.h"
44 #include "internal.h"
45 #include "get_bits.h"
46 #include "thread.h"
47 #include "vp8.h"
48 
49 #define VP8X_FLAG_ANIMATION 0x02
50 #define VP8X_FLAG_XMP_METADATA 0x04
51 #define VP8X_FLAG_EXIF_METADATA 0x08
52 #define VP8X_FLAG_ALPHA 0x10
53 #define VP8X_FLAG_ICC 0x20
54 
55 #define MAX_PALETTE_SIZE 256
56 #define MAX_CACHE_BITS 11
57 #define NUM_CODE_LENGTH_CODES 19
58 #define HUFFMAN_CODES_PER_META_CODE 5
59 #define NUM_LITERAL_CODES 256
60 #define NUM_LENGTH_CODES 24
61 #define NUM_DISTANCE_CODES 40
62 #define NUM_SHORT_DISTANCES 120
63 #define MAX_HUFFMAN_CODE_LENGTH 15
64 
65 static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE] = {
69 };
70 
72  17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
73 };
74 
75 static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2] = {
76  { 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 },
77  { 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 },
78  { 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 },
79  { 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 },
80  { 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 },
81  { 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 },
82  { 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 },
83  { 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 },
84  { 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 },
85  { 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 },
86  { 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 },
87  { 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 },
88  { 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 },
89  { -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 },
90  { -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 }
91 };
92 
96 };
97 
103 };
104 
110 };
111 
127 };
128 
135 };
136 
137 /* The structure of WebP lossless is an optional series of transformation data,
138  * followed by the primary image. The primary image also optionally contains
139  * an entropy group mapping if there are multiple entropy groups. There is a
140  * basic image type called an "entropy coded image" that is used for all of
141  * these. The type of each entropy coded image is referred to by the
142  * specification as its role. */
143 enum ImageRole {
144  /* Primary Image: Stores the actual pixels of the image. */
146 
147  /* Entropy Image: Defines which Huffman group to use for different areas of
148  * the primary image. */
150 
151  /* Predictors: Defines which predictor type to use for different areas of
152  * the primary image. */
154 
155  /* Color Transform Data: Defines the color transformation for different
156  * areas of the primary image. */
158 
159  /* Color Index: Stored as an image of height == 1. */
161 
163 };
164 
165 typedef struct HuffReader {
166  VLC vlc; /* Huffman decoder context */
167  int simple; /* whether to use simple mode */
168  int nb_symbols; /* number of coded symbols */
169  uint16_t simple_symbols[2]; /* symbols for simple mode */
170 } HuffReader;
171 
172 typedef struct ImageContext {
173  enum ImageRole role; /* role of this image */
174  AVFrame *frame; /* AVFrame for data */
175  int color_cache_bits; /* color cache size, log2 */
176  uint32_t *color_cache; /* color cache data */
177  int nb_huffman_groups; /* number of huffman groups */
178  HuffReader *huffman_groups; /* reader for each huffman group */
179  int size_reduction; /* relative size compared to primary image, log2 */
181 } ImageContext;
182 
183 typedef struct WebPContext {
184  VP8Context v; /* VP8 Context used for lossy decoding */
185  GetBitContext gb; /* bitstream reader for main image chunk */
186  AVFrame *alpha_frame; /* AVFrame for alpha data decompressed from VP8L */
187  AVCodecContext *avctx; /* parent AVCodecContext */
188  int initialized; /* set once the VP8 context is initialized */
189  int has_alpha; /* has a separate alpha chunk */
190  enum AlphaCompression alpha_compression; /* compression type for alpha chunk */
191  enum AlphaFilter alpha_filter; /* filtering method for alpha chunk */
192  uint8_t *alpha_data; /* alpha chunk data */
193  int alpha_data_size; /* alpha chunk data size */
194  int width; /* image width */
195  int height; /* image height */
196  int lossless; /* indicates lossless or lossy */
197 
198  int nb_transforms; /* number of transforms */
199  enum TransformType transforms[4]; /* transformations used in the image, in order */
200  int reduced_width; /* reduced width for index image, if applicable */
201  int nb_huffman_groups; /* number of huffman groups in the primary image */
202  ImageContext image[IMAGE_ROLE_NB]; /* image context for each role */
203 } WebPContext;
204 
205 #define GET_PIXEL(frame, x, y) \
206  ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x))
207 
208 #define GET_PIXEL_COMP(frame, x, y, c) \
209  (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c))
210 
211 static void image_ctx_free(ImageContext *img)
212 {
213  int i, j;
214 
215  av_free(img->color_cache);
216  if (img->role != IMAGE_ROLE_ARGB && !img->is_alpha_primary)
217  av_frame_free(&img->frame);
218  if (img->huffman_groups) {
219  for (i = 0; i < img->nb_huffman_groups; i++) {
220  for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++)
221  ff_free_vlc(&img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE + j].vlc);
222  }
223  av_free(img->huffman_groups);
224  }
225  memset(img, 0, sizeof(*img));
226 }
227 
228 
229 /* Differs from get_vlc2() in the following ways:
230  * - codes are bit-reversed
231  * - assumes 8-bit table to make reversal simpler
232  * - assumes max depth of 2 since the max code length for WebP is 15
233  */
235 {
236  int n, nb_bits;
237  unsigned int index;
238  int code;
239 
240  OPEN_READER(re, gb);
241  UPDATE_CACHE(re, gb);
242 
243  index = SHOW_UBITS(re, gb, 8);
244  index = ff_reverse[index];
245  code = table[index][0];
246  n = table[index][1];
247 
248  if (n < 0) {
249  LAST_SKIP_BITS(re, gb, 8);
250  UPDATE_CACHE(re, gb);
251 
252  nb_bits = -n;
253 
254  index = SHOW_UBITS(re, gb, nb_bits);
255  index = (ff_reverse[index] >> (8 - nb_bits)) + code;
256  code = table[index][0];
257  n = table[index][1];
258  }
259  SKIP_BITS(re, gb, n);
260 
261  CLOSE_READER(re, gb);
262 
263  return code;
264 }
265 
267 {
268  if (r->simple) {
269  if (r->nb_symbols == 1)
270  return r->simple_symbols[0];
271  else
272  return r->simple_symbols[get_bits1(gb)];
273  } else
274  return webp_get_vlc(gb, r->vlc.table);
275 }
276 
277 static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
278  int alphabet_size)
279 {
280  int len = 0, sym, code = 0, ret;
281  int max_code_length = 0;
282  uint16_t *codes;
283 
284  /* special-case 1 symbol since the vlc reader cannot handle it */
285  for (sym = 0; sym < alphabet_size; sym++) {
286  if (code_lengths[sym] > 0) {
287  len++;
288  code = sym;
289  if (len > 1)
290  break;
291  }
292  }
293  if (len == 1) {
294  r->nb_symbols = 1;
295  r->simple_symbols[0] = code;
296  r->simple = 1;
297  return 0;
298  }
299 
300  for (sym = 0; sym < alphabet_size; sym++)
301  max_code_length = FFMAX(max_code_length, code_lengths[sym]);
302 
303  if (max_code_length == 0 || max_code_length > MAX_HUFFMAN_CODE_LENGTH)
304  return AVERROR(EINVAL);
305 
306  codes = av_malloc(alphabet_size * sizeof(*codes));
307  if (!codes)
308  return AVERROR(ENOMEM);
309 
310  code = 0;
311  r->nb_symbols = 0;
312  for (len = 1; len <= max_code_length; len++) {
313  for (sym = 0; sym < alphabet_size; sym++) {
314  if (code_lengths[sym] != len)
315  continue;
316  codes[sym] = code++;
317  r->nb_symbols++;
318  }
319  code <<= 1;
320  }
321  if (!r->nb_symbols) {
322  av_free(codes);
323  return AVERROR_INVALIDDATA;
324  }
325 
326  ret = init_vlc(&r->vlc, 8, alphabet_size,
327  code_lengths, sizeof(*code_lengths), sizeof(*code_lengths),
328  codes, sizeof(*codes), sizeof(*codes), 0);
329  if (ret < 0) {
330  av_free(codes);
331  return ret;
332  }
333  r->simple = 0;
334 
335  av_free(codes);
336  return 0;
337 }
338 
340 {
341  hc->nb_symbols = get_bits1(&s->gb) + 1;
342 
343  if (get_bits1(&s->gb))
344  hc->simple_symbols[0] = get_bits(&s->gb, 8);
345  else
346  hc->simple_symbols[0] = get_bits1(&s->gb);
347 
348  if (hc->nb_symbols == 2)
349  hc->simple_symbols[1] = get_bits(&s->gb, 8);
350 
351  hc->simple = 1;
352 }
353 
355  int alphabet_size)
356 {
357  HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
358  int *code_lengths = NULL;
359  int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
360  int i, symbol, max_symbol, prev_code_len, ret;
361  int num_codes = 4 + get_bits(&s->gb, 4);
362 
363  if (num_codes > NUM_CODE_LENGTH_CODES)
364  return AVERROR_INVALIDDATA;
365 
366  for (i = 0; i < num_codes; i++)
367  code_length_code_lengths[code_length_code_order[i]] = get_bits(&s->gb, 3);
368 
369  ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths,
371  if (ret < 0)
372  goto finish;
373 
374  code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths));
375  if (!code_lengths) {
376  ret = AVERROR(ENOMEM);
377  goto finish;
378  }
379 
380  if (get_bits1(&s->gb)) {
381  int bits = 2 + 2 * get_bits(&s->gb, 3);
382  max_symbol = 2 + get_bits(&s->gb, bits);
383  if (max_symbol > alphabet_size) {
384  av_log(s->avctx, AV_LOG_ERROR, "max symbol %d > alphabet size %d\n",
385  max_symbol, alphabet_size);
386  ret = AVERROR_INVALIDDATA;
387  goto finish;
388  }
389  } else {
390  max_symbol = alphabet_size;
391  }
392 
393  prev_code_len = 8;
394  symbol = 0;
395  while (symbol < alphabet_size) {
396  int code_len;
397 
398  if (!max_symbol--)
399  break;
400  code_len = huff_reader_get_symbol(&code_len_hc, &s->gb);
401  if (code_len < 16) {
402  /* Code length code [0..15] indicates literal code lengths. */
403  code_lengths[symbol++] = code_len;
404  if (code_len)
405  prev_code_len = code_len;
406  } else {
407  int repeat = 0, length = 0;
408  switch (code_len) {
409  case 16:
410  /* Code 16 repeats the previous non-zero value [3..6] times,
411  * i.e., 3 + ReadBits(2) times. If code 16 is used before a
412  * non-zero value has been emitted, a value of 8 is repeated. */
413  repeat = 3 + get_bits(&s->gb, 2);
414  length = prev_code_len;
415  break;
416  case 17:
417  /* Code 17 emits a streak of zeros [3..10], i.e.,
418  * 3 + ReadBits(3) times. */
419  repeat = 3 + get_bits(&s->gb, 3);
420  break;
421  case 18:
422  /* Code 18 emits a streak of zeros of length [11..138], i.e.,
423  * 11 + ReadBits(7) times. */
424  repeat = 11 + get_bits(&s->gb, 7);
425  break;
426  }
427  if (symbol + repeat > alphabet_size) {
429  "invalid symbol %d + repeat %d > alphabet size %d\n",
430  symbol, repeat, alphabet_size);
431  ret = AVERROR_INVALIDDATA;
432  goto finish;
433  }
434  while (repeat-- > 0)
435  code_lengths[symbol++] = length;
436  }
437  }
438 
439  ret = huff_reader_build_canonical(hc, code_lengths, alphabet_size);
440 
441 finish:
442  ff_free_vlc(&code_len_hc.vlc);
443  av_free(code_lengths);
444  return ret;
445 }
446 
447 static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
448  int w, int h);
449 
450 #define PARSE_BLOCK_SIZE(w, h) do { \
451  block_bits = get_bits(&s->gb, 3) + 2; \
452  blocks_w = FFALIGN((w), 1 << block_bits) >> block_bits; \
453  blocks_h = FFALIGN((h), 1 << block_bits) >> block_bits; \
454 } while (0)
455 
457 {
458  ImageContext *img;
459  int ret, block_bits, width, blocks_w, blocks_h, x, y, max;
460 
461  width = s->width;
462  if (s->reduced_width > 0)
463  width = s->reduced_width;
464 
465  PARSE_BLOCK_SIZE(width, s->height);
466 
467  ret = decode_entropy_coded_image(s, IMAGE_ROLE_ENTROPY, blocks_w, blocks_h);
468  if (ret < 0)
469  return ret;
470 
471  img = &s->image[IMAGE_ROLE_ENTROPY];
472  img->size_reduction = block_bits;
473 
474  /* the number of huffman groups is determined by the maximum group number
475  * coded in the entropy image */
476  max = 0;
477  for (y = 0; y < img->frame->height; y++) {
478  for (x = 0; x < img->frame->width; x++) {
479  int p0 = GET_PIXEL_COMP(img->frame, x, y, 1);
480  int p1 = GET_PIXEL_COMP(img->frame, x, y, 2);
481  int p = p0 << 8 | p1;
482  max = FFMAX(max, p);
483  }
484  }
485  s->nb_huffman_groups = max + 1;
486 
487  return 0;
488 }
489 
491 {
492  int block_bits, blocks_w, blocks_h, ret;
493 
494  PARSE_BLOCK_SIZE(s->width, s->height);
495 
497  blocks_h);
498  if (ret < 0)
499  return ret;
500 
501  s->image[IMAGE_ROLE_PREDICTOR].size_reduction = block_bits;
502 
503  return 0;
504 }
505 
507 {
508  int block_bits, blocks_w, blocks_h, ret;
509 
510  PARSE_BLOCK_SIZE(s->width, s->height);
511 
513  blocks_h);
514  if (ret < 0)
515  return ret;
516 
518 
519  return 0;
520 }
521 
523 {
524  ImageContext *img;
525  int width_bits, index_size, ret, x;
526  uint8_t *ct;
527 
528  index_size = get_bits(&s->gb, 8) + 1;
529 
530  if (index_size <= 2)
531  width_bits = 3;
532  else if (index_size <= 4)
533  width_bits = 2;
534  else if (index_size <= 16)
535  width_bits = 1;
536  else
537  width_bits = 0;
538 
540  index_size, 1);
541  if (ret < 0)
542  return ret;
543 
544  img = &s->image[IMAGE_ROLE_COLOR_INDEXING];
545  img->size_reduction = width_bits;
546  if (width_bits > 0)
547  s->reduced_width = (s->width + ((1 << width_bits) - 1)) >> width_bits;
548 
549  /* color index values are delta-coded */
550  ct = img->frame->data[0] + 4;
551  for (x = 4; x < img->frame->width * 4; x++, ct++)
552  ct[0] += ct[-4];
553 
554  return 0;
555 }
556 
558  int x, int y)
559 {
561  int group = 0;
562 
563  if (gimg->size_reduction > 0) {
564  int group_x = x >> gimg->size_reduction;
565  int group_y = y >> gimg->size_reduction;
566  int g0 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 1);
567  int g1 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 2);
568  group = g0 << 8 | g1;
569  }
570 
571  return &img->huffman_groups[group * HUFFMAN_CODES_PER_META_CODE];
572 }
573 
574 static av_always_inline void color_cache_put(ImageContext *img, uint32_t c)
575 {
576  uint32_t cache_idx = (0x1E35A7BD * c) >> (32 - img->color_cache_bits);
577  img->color_cache[cache_idx] = c;
578 }
579 
581  int w, int h)
582 {
583  ImageContext *img;
584  HuffReader *hg;
585  int i, j, ret, x, y, width;
586 
587  img = &s->image[role];
588  img->role = role;
589 
590  if (!img->frame) {
591  img->frame = av_frame_alloc();
592  if (!img->frame)
593  return AVERROR(ENOMEM);
594  }
595 
596  img->frame->format = AV_PIX_FMT_ARGB;
597  img->frame->width = w;
598  img->frame->height = h;
599 
600  if (role == IMAGE_ROLE_ARGB && !img->is_alpha_primary) {
601  ThreadFrame pt = { .f = img->frame };
602  ret = ff_thread_get_buffer(s->avctx, &pt, 0);
603  } else
604  ret = av_frame_get_buffer(img->frame, 1);
605  if (ret < 0)
606  return ret;
607 
608  if (get_bits1(&s->gb)) {
609  img->color_cache_bits = get_bits(&s->gb, 4);
610  if (img->color_cache_bits < 1 || img->color_cache_bits > 11) {
611  av_log(s->avctx, AV_LOG_ERROR, "invalid color cache bits: %d\n",
612  img->color_cache_bits);
613  return AVERROR_INVALIDDATA;
614  }
616  sizeof(*img->color_cache));
617  if (!img->color_cache)
618  return AVERROR(ENOMEM);
619  } else {
620  img->color_cache_bits = 0;
621  }
622 
623  img->nb_huffman_groups = 1;
624  if (role == IMAGE_ROLE_ARGB && get_bits1(&s->gb)) {
625  ret = decode_entropy_image(s);
626  if (ret < 0)
627  return ret;
629  }
632  sizeof(*img->huffman_groups));
633  if (!img->huffman_groups)
634  return AVERROR(ENOMEM);
635 
636  for (i = 0; i < img->nb_huffman_groups; i++) {
638  for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) {
639  int alphabet_size = alphabet_sizes[j];
640  if (!j && img->color_cache_bits > 0)
641  alphabet_size += 1 << img->color_cache_bits;
642 
643  if (get_bits1(&s->gb)) {
644  read_huffman_code_simple(s, &hg[j]);
645  } else {
646  ret = read_huffman_code_normal(s, &hg[j], alphabet_size);
647  if (ret < 0)
648  return ret;
649  }
650  }
651  }
652 
653  width = img->frame->width;
654  if (role == IMAGE_ROLE_ARGB && s->reduced_width > 0)
655  width = s->reduced_width;
656 
657  x = 0; y = 0;
658  while (y < img->frame->height) {
659  int v;
660 
661  hg = get_huffman_group(s, img, x, y);
663  if (v < NUM_LITERAL_CODES) {
664  /* literal pixel values */
665  uint8_t *p = GET_PIXEL(img->frame, x, y);
666  p[2] = v;
667  p[1] = huff_reader_get_symbol(&hg[HUFF_IDX_RED], &s->gb);
668  p[3] = huff_reader_get_symbol(&hg[HUFF_IDX_BLUE], &s->gb);
669  p[0] = huff_reader_get_symbol(&hg[HUFF_IDX_ALPHA], &s->gb);
670  if (img->color_cache_bits)
671  color_cache_put(img, AV_RB32(p));
672  x++;
673  if (x == width) {
674  x = 0;
675  y++;
676  }
677  } else if (v < NUM_LITERAL_CODES + NUM_LENGTH_CODES) {
678  /* LZ77 backwards mapping */
679  int prefix_code, length, distance, ref_x, ref_y;
680 
681  /* parse length and distance */
682  prefix_code = v - NUM_LITERAL_CODES;
683  if (prefix_code < 4) {
684  length = prefix_code + 1;
685  } else {
686  int extra_bits = (prefix_code - 2) >> 1;
687  int offset = 2 + (prefix_code & 1) << extra_bits;
688  length = offset + get_bits(&s->gb, extra_bits) + 1;
689  }
690  prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb);
691  if (prefix_code < 4) {
692  distance = prefix_code + 1;
693  } else {
694  int extra_bits = prefix_code - 2 >> 1;
695  int offset = 2 + (prefix_code & 1) << extra_bits;
696  distance = offset + get_bits(&s->gb, extra_bits) + 1;
697  }
698 
699  /* find reference location */
700  if (distance <= NUM_SHORT_DISTANCES) {
701  int xi = lz77_distance_offsets[distance - 1][0];
702  int yi = lz77_distance_offsets[distance - 1][1];
703  distance = FFMAX(1, xi + yi * width);
704  } else {
705  distance -= NUM_SHORT_DISTANCES;
706  }
707  ref_x = x;
708  ref_y = y;
709  if (distance <= x) {
710  ref_x -= distance;
711  distance = 0;
712  } else {
713  ref_x = 0;
714  distance -= x;
715  }
716  while (distance >= width) {
717  ref_y--;
718  distance -= width;
719  }
720  if (distance > 0) {
721  ref_x = width - distance;
722  ref_y--;
723  }
724  ref_x = FFMAX(0, ref_x);
725  ref_y = FFMAX(0, ref_y);
726 
727  /* copy pixels
728  * source and dest regions can overlap and wrap lines, so just
729  * copy per-pixel */
730  for (i = 0; i < length; i++) {
731  uint8_t *p_ref = GET_PIXEL(img->frame, ref_x, ref_y);
732  uint8_t *p = GET_PIXEL(img->frame, x, y);
733 
734  AV_COPY32(p, p_ref);
735  if (img->color_cache_bits)
736  color_cache_put(img, AV_RB32(p));
737  x++;
738  ref_x++;
739  if (x == width) {
740  x = 0;
741  y++;
742  }
743  if (ref_x == width) {
744  ref_x = 0;
745  ref_y++;
746  }
747  if (y == img->frame->height || ref_y == img->frame->height)
748  break;
749  }
750  } else {
751  /* read from color cache */
752  uint8_t *p = GET_PIXEL(img->frame, x, y);
753  int cache_idx = v - (NUM_LITERAL_CODES + NUM_LENGTH_CODES);
754 
755  if (!img->color_cache_bits) {
756  av_log(s->avctx, AV_LOG_ERROR, "color cache not found\n");
757  return AVERROR_INVALIDDATA;
758  }
759  if (cache_idx >= 1 << img->color_cache_bits) {
761  "color cache index out-of-bounds\n");
762  return AVERROR_INVALIDDATA;
763  }
764  AV_WB32(p, img->color_cache[cache_idx]);
765  x++;
766  if (x == width) {
767  x = 0;
768  y++;
769  }
770  }
771  }
772 
773  return 0;
774 }
775 
776 /* PRED_MODE_BLACK */
777 static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
778  const uint8_t *p_t, const uint8_t *p_tr)
779 {
780  AV_WB32(p, 0xFF000000);
781 }
782 
783 /* PRED_MODE_L */
784 static void inv_predict_1(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
785  const uint8_t *p_t, const uint8_t *p_tr)
786 {
787  AV_COPY32(p, p_l);
788 }
789 
790 /* PRED_MODE_T */
791 static void inv_predict_2(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
792  const uint8_t *p_t, const uint8_t *p_tr)
793 {
794  AV_COPY32(p, p_t);
795 }
796 
797 /* PRED_MODE_TR */
798 static void inv_predict_3(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
799  const uint8_t *p_t, const uint8_t *p_tr)
800 {
801  AV_COPY32(p, p_tr);
802 }
803 
804 /* PRED_MODE_TL */
805 static void inv_predict_4(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
806  const uint8_t *p_t, const uint8_t *p_tr)
807 {
808  AV_COPY32(p, p_tl);
809 }
810 
811 /* PRED_MODE_AVG_T_AVG_L_TR */
812 static void inv_predict_5(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
813  const uint8_t *p_t, const uint8_t *p_tr)
814 {
815  p[0] = p_t[0] + (p_l[0] + p_tr[0] >> 1) >> 1;
816  p[1] = p_t[1] + (p_l[1] + p_tr[1] >> 1) >> 1;
817  p[2] = p_t[2] + (p_l[2] + p_tr[2] >> 1) >> 1;
818  p[3] = p_t[3] + (p_l[3] + p_tr[3] >> 1) >> 1;
819 }
820 
821 /* PRED_MODE_AVG_L_TL */
822 static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
823  const uint8_t *p_t, const uint8_t *p_tr)
824 {
825  p[0] = p_l[0] + p_tl[0] >> 1;
826  p[1] = p_l[1] + p_tl[1] >> 1;
827  p[2] = p_l[2] + p_tl[2] >> 1;
828  p[3] = p_l[3] + p_tl[3] >> 1;
829 }
830 
831 /* PRED_MODE_AVG_L_T */
832 static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
833  const uint8_t *p_t, const uint8_t *p_tr)
834 {
835  p[0] = p_l[0] + p_t[0] >> 1;
836  p[1] = p_l[1] + p_t[1] >> 1;
837  p[2] = p_l[2] + p_t[2] >> 1;
838  p[3] = p_l[3] + p_t[3] >> 1;
839 }
840 
841 /* PRED_MODE_AVG_TL_T */
842 static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
843  const uint8_t *p_t, const uint8_t *p_tr)
844 {
845  p[0] = p_tl[0] + p_t[0] >> 1;
846  p[1] = p_tl[1] + p_t[1] >> 1;
847  p[2] = p_tl[2] + p_t[2] >> 1;
848  p[3] = p_tl[3] + p_t[3] >> 1;
849 }
850 
851 /* PRED_MODE_AVG_T_TR */
852 static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
853  const uint8_t *p_t, const uint8_t *p_tr)
854 {
855  p[0] = p_t[0] + p_tr[0] >> 1;
856  p[1] = p_t[1] + p_tr[1] >> 1;
857  p[2] = p_t[2] + p_tr[2] >> 1;
858  p[3] = p_t[3] + p_tr[3] >> 1;
859 }
860 
861 /* PRED_MODE_AVG_AVG_L_TL_AVG_T_TR */
862 static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
863  const uint8_t *p_t, const uint8_t *p_tr)
864 {
865  p[0] = (p_l[0] + p_tl[0] >> 1) + (p_t[0] + p_tr[0] >> 1) >> 1;
866  p[1] = (p_l[1] + p_tl[1] >> 1) + (p_t[1] + p_tr[1] >> 1) >> 1;
867  p[2] = (p_l[2] + p_tl[2] >> 1) + (p_t[2] + p_tr[2] >> 1) >> 1;
868  p[3] = (p_l[3] + p_tl[3] >> 1) + (p_t[3] + p_tr[3] >> 1) >> 1;
869 }
870 
871 /* PRED_MODE_SELECT */
872 static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
873  const uint8_t *p_t, const uint8_t *p_tr)
874 {
875  int diff = (FFABS(p_l[0] - p_tl[0]) - FFABS(p_t[0] - p_tl[0])) +
876  (FFABS(p_l[1] - p_tl[1]) - FFABS(p_t[1] - p_tl[1])) +
877  (FFABS(p_l[2] - p_tl[2]) - FFABS(p_t[2] - p_tl[2])) +
878  (FFABS(p_l[3] - p_tl[3]) - FFABS(p_t[3] - p_tl[3]));
879  if (diff <= 0)
880  AV_COPY32(p, p_t);
881  else
882  AV_COPY32(p, p_l);
883 }
884 
885 /* PRED_MODE_ADD_SUBTRACT_FULL */
886 static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
887  const uint8_t *p_t, const uint8_t *p_tr)
888 {
889  p[0] = av_clip_uint8(p_l[0] + p_t[0] - p_tl[0]);
890  p[1] = av_clip_uint8(p_l[1] + p_t[1] - p_tl[1]);
891  p[2] = av_clip_uint8(p_l[2] + p_t[2] - p_tl[2]);
892  p[3] = av_clip_uint8(p_l[3] + p_t[3] - p_tl[3]);
893 }
894 
896 {
897  int d = a + b >> 1;
898  return av_clip_uint8(d + (d - c) / 2);
899 }
900 
901 /* PRED_MODE_ADD_SUBTRACT_HALF */
902 static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
903  const uint8_t *p_t, const uint8_t *p_tr)
904 {
905  p[0] = clamp_add_subtract_half(p_l[0], p_t[0], p_tl[0]);
906  p[1] = clamp_add_subtract_half(p_l[1], p_t[1], p_tl[1]);
907  p[2] = clamp_add_subtract_half(p_l[2], p_t[2], p_tl[2]);
908  p[3] = clamp_add_subtract_half(p_l[3], p_t[3], p_tl[3]);
909 }
910 
911 typedef void (*inv_predict_func)(uint8_t *p, const uint8_t *p_l,
912  const uint8_t *p_tl, const uint8_t *p_t,
913  const uint8_t *p_tr);
914 
915 static const inv_predict_func inverse_predict[14] = {
920 };
921 
922 static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
923 {
924  uint8_t *dec, *p_l, *p_tl, *p_t, *p_tr;
925  uint8_t p[4];
926 
927  dec = GET_PIXEL(frame, x, y);
928  p_l = GET_PIXEL(frame, x - 1, y);
929  p_tl = GET_PIXEL(frame, x - 1, y - 1);
930  p_t = GET_PIXEL(frame, x, y - 1);
931  if (x == frame->width - 1)
932  p_tr = GET_PIXEL(frame, 0, y);
933  else
934  p_tr = GET_PIXEL(frame, x + 1, y - 1);
935 
936  inverse_predict[m](p, p_l, p_tl, p_t, p_tr);
937 
938  dec[0] += p[0];
939  dec[1] += p[1];
940  dec[2] += p[2];
941  dec[3] += p[3];
942 }
943 
945 {
946  ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
948  int x, y;
949 
950  for (y = 0; y < img->frame->height; y++) {
951  for (x = 0; x < img->frame->width; x++) {
952  int tx = x >> pimg->size_reduction;
953  int ty = y >> pimg->size_reduction;
954  enum PredictionMode m = GET_PIXEL_COMP(pimg->frame, tx, ty, 2);
955 
956  if (x == 0) {
957  if (y == 0)
958  m = PRED_MODE_BLACK;
959  else
960  m = PRED_MODE_T;
961  } else if (y == 0)
962  m = PRED_MODE_L;
963 
964  if (m > 13) {
966  "invalid predictor mode: %d\n", m);
967  return AVERROR_INVALIDDATA;
968  }
969  inverse_prediction(img->frame, m, x, y);
970  }
971  }
972  return 0;
973 }
974 
976  uint8_t color)
977 {
978  return (int)ff_u8_to_s8(color_pred) * ff_u8_to_s8(color) >> 5;
979 }
980 
982 {
983  ImageContext *img, *cimg;
984  int x, y, cx, cy;
985  uint8_t *p, *cp;
986 
987  img = &s->image[IMAGE_ROLE_ARGB];
988  cimg = &s->image[IMAGE_ROLE_COLOR_TRANSFORM];
989 
990  for (y = 0; y < img->frame->height; y++) {
991  for (x = 0; x < img->frame->width; x++) {
992  cx = x >> cimg->size_reduction;
993  cy = y >> cimg->size_reduction;
994  cp = GET_PIXEL(cimg->frame, cx, cy);
995  p = GET_PIXEL(img->frame, x, y);
996 
997  p[1] += color_transform_delta(cp[3], p[2]);
998  p[3] += color_transform_delta(cp[2], p[2]) +
999  color_transform_delta(cp[1], p[1]);
1000  }
1001  }
1002  return 0;
1003 }
1004 
1006 {
1007  int x, y;
1008  ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
1009 
1010  for (y = 0; y < img->frame->height; y++) {
1011  for (x = 0; x < img->frame->width; x++) {
1012  uint8_t *p = GET_PIXEL(img->frame, x, y);
1013  p[1] += p[2];
1014  p[3] += p[2];
1015  }
1016  }
1017  return 0;
1018 }
1019 
1021 {
1022  ImageContext *img;
1023  ImageContext *pal;
1024  int i, x, y;
1025  uint8_t *p, *pi;
1026 
1027  img = &s->image[IMAGE_ROLE_ARGB];
1028  pal = &s->image[IMAGE_ROLE_COLOR_INDEXING];
1029 
1030  if (pal->size_reduction > 0) {
1031  GetBitContext gb_g;
1032  uint8_t *line;
1033  int pixel_bits = 8 >> pal->size_reduction;
1034 
1035  line = av_malloc(img->frame->linesize[0]);
1036  if (!line)
1037  return AVERROR(ENOMEM);
1038 
1039  for (y = 0; y < img->frame->height; y++) {
1040  p = GET_PIXEL(img->frame, 0, y);
1041  memcpy(line, p, img->frame->linesize[0]);
1042  init_get_bits(&gb_g, line, img->frame->linesize[0] * 8);
1043  skip_bits(&gb_g, 16);
1044  i = 0;
1045  for (x = 0; x < img->frame->width; x++) {
1046  p = GET_PIXEL(img->frame, x, y);
1047  p[2] = get_bits(&gb_g, pixel_bits);
1048  i++;
1049  if (i == 1 << pal->size_reduction) {
1050  skip_bits(&gb_g, 24);
1051  i = 0;
1052  }
1053  }
1054  }
1055  av_free(line);
1056  }
1057 
1058  for (y = 0; y < img->frame->height; y++) {
1059  for (x = 0; x < img->frame->width; x++) {
1060  p = GET_PIXEL(img->frame, x, y);
1061  i = p[2];
1062  if (i >= pal->frame->width) {
1063  av_log(s->avctx, AV_LOG_ERROR, "invalid palette index %d\n", i);
1064  return AVERROR_INVALIDDATA;
1065  }
1066  pi = GET_PIXEL(pal->frame, i, 0);
1067  AV_COPY32(p, pi);
1068  }
1069  }
1070 
1071  return 0;
1072 }
1073 
1075  int *got_frame, uint8_t *data_start,
1076  unsigned int data_size, int is_alpha_chunk)
1077 {
1078  WebPContext *s = avctx->priv_data;
1079  int w, h, ret, i;
1080 
1081  if (!is_alpha_chunk) {
1082  s->lossless = 1;
1083  avctx->pix_fmt = AV_PIX_FMT_ARGB;
1084  }
1085 
1086  ret = init_get_bits(&s->gb, data_start, data_size * 8);
1087  if (ret < 0)
1088  return ret;
1089 
1090  if (!is_alpha_chunk) {
1091  if (get_bits(&s->gb, 8) != 0x2F) {
1092  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless signature\n");
1093  return AVERROR_INVALIDDATA;
1094  }
1095 
1096  w = get_bits(&s->gb, 14) + 1;
1097  h = get_bits(&s->gb, 14) + 1;
1098  if (s->width && s->width != w) {
1099  av_log(avctx, AV_LOG_WARNING, "Width mismatch. %d != %d\n",
1100  s->width, w);
1101  }
1102  s->width = w;
1103  if (s->height && s->height != h) {
1104  av_log(avctx, AV_LOG_WARNING, "Height mismatch. %d != %d\n",
1105  s->width, w);
1106  }
1107  s->height = h;
1108 
1109  ret = ff_set_dimensions(avctx, s->width, s->height);
1110  if (ret < 0)
1111  return ret;
1112 
1113  s->has_alpha = get_bits1(&s->gb);
1114 
1115  if (get_bits(&s->gb, 3) != 0x0) {
1116  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless version\n");
1117  return AVERROR_INVALIDDATA;
1118  }
1119  } else {
1120  if (!s->width || !s->height)
1121  return AVERROR_BUG;
1122  w = s->width;
1123  h = s->height;
1124  }
1125 
1126  /* parse transformations */
1127  s->nb_transforms = 0;
1128  s->reduced_width = 0;
1129  while (get_bits1(&s->gb)) {
1130  enum TransformType transform = get_bits(&s->gb, 2);
1131  s->transforms[s->nb_transforms++] = transform;
1132  switch (transform) {
1133  case PREDICTOR_TRANSFORM:
1134  ret = parse_transform_predictor(s);
1135  break;
1136  case COLOR_TRANSFORM:
1137  ret = parse_transform_color(s);
1138  break;
1141  break;
1142  }
1143  if (ret < 0)
1144  goto free_and_return;
1145  }
1146 
1147  /* decode primary image */
1148  s->image[IMAGE_ROLE_ARGB].frame = p;
1149  if (is_alpha_chunk)
1152  if (ret < 0)
1153  goto free_and_return;
1154 
1155  /* apply transformations */
1156  for (i = s->nb_transforms - 1; i >= 0; i--) {
1157  switch (s->transforms[i]) {
1158  case PREDICTOR_TRANSFORM:
1159  ret = apply_predictor_transform(s);
1160  break;
1161  case COLOR_TRANSFORM:
1162  ret = apply_color_transform(s);
1163  break;
1164  case SUBTRACT_GREEN:
1166  break;
1169  break;
1170  }
1171  if (ret < 0)
1172  goto free_and_return;
1173  }
1174 
1175  *got_frame = 1;
1177  p->key_frame = 1;
1178  ret = data_size;
1179 
1180 free_and_return:
1181  for (i = 0; i < IMAGE_ROLE_NB; i++)
1182  image_ctx_free(&s->image[i]);
1183 
1184  return ret;
1185 }
1186 
1187 static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
1188 {
1189  int x, y, ls;
1190  uint8_t *dec;
1191 
1192  ls = frame->linesize[3];
1193 
1194  /* filter first row using horizontal filter */
1195  dec = frame->data[3] + 1;
1196  for (x = 1; x < frame->width; x++, dec++)
1197  *dec += *(dec - 1);
1198 
1199  /* filter first column using vertical filter */
1200  dec = frame->data[3] + ls;
1201  for (y = 1; y < frame->height; y++, dec += ls)
1202  *dec += *(dec - ls);
1203 
1204  /* filter the rest using the specified filter */
1205  switch (m) {
1207  for (y = 1; y < frame->height; y++) {
1208  dec = frame->data[3] + y * ls + 1;
1209  for (x = 1; x < frame->width; x++, dec++)
1210  *dec += *(dec - 1);
1211  }
1212  break;
1213  case ALPHA_FILTER_VERTICAL:
1214  for (y = 1; y < frame->height; y++) {
1215  dec = frame->data[3] + y * ls + 1;
1216  for (x = 1; x < frame->width; x++, dec++)
1217  *dec += *(dec - ls);
1218  }
1219  break;
1220  case ALPHA_FILTER_GRADIENT:
1221  for (y = 1; y < frame->height; y++) {
1222  dec = frame->data[3] + y * ls + 1;
1223  for (x = 1; x < frame->width; x++, dec++)
1224  dec[0] += av_clip_uint8(*(dec - 1) + *(dec - ls) - *(dec - ls - 1));
1225  }
1226  break;
1227  }
1228 }
1229 
1231  uint8_t *data_start,
1232  unsigned int data_size)
1233 {
1234  WebPContext *s = avctx->priv_data;
1235  int x, y, ret;
1236 
1238  GetByteContext gb;
1239 
1240  bytestream2_init(&gb, data_start, data_size);
1241  for (y = 0; y < s->height; y++)
1242  bytestream2_get_buffer(&gb, p->data[3] + p->linesize[3] * y,
1243  s->width);
1244  } else if (s->alpha_compression == ALPHA_COMPRESSION_VP8L) {
1245  uint8_t *ap, *pp;
1246  int alpha_got_frame = 0;
1247 
1248  s->alpha_frame = av_frame_alloc();
1249  if (!s->alpha_frame)
1250  return AVERROR(ENOMEM);
1251 
1252  ret = vp8_lossless_decode_frame(avctx, s->alpha_frame, &alpha_got_frame,
1253  data_start, data_size, 1);
1254  if (ret < 0) {
1256  return ret;
1257  }
1258  if (!alpha_got_frame) {
1260  return AVERROR_INVALIDDATA;
1261  }
1262 
1263  /* copy green component of alpha image to alpha plane of primary image */
1264  for (y = 0; y < s->height; y++) {
1265  ap = GET_PIXEL(s->alpha_frame, 0, y) + 2;
1266  pp = p->data[3] + p->linesize[3] * y;
1267  for (x = 0; x < s->width; x++) {
1268  *pp = *ap;
1269  pp++;
1270  ap += 4;
1271  }
1272  }
1274  }
1275 
1276  /* apply alpha filtering */
1277  if (s->alpha_filter)
1279 
1280  return 0;
1281 }
1282 
1284  int *got_frame, uint8_t *data_start,
1285  unsigned int data_size)
1286 {
1287  WebPContext *s = avctx->priv_data;
1288  AVPacket pkt;
1289  int ret;
1290 
1291  if (!s->initialized) {
1292  ff_vp8_decode_init(avctx);
1293  s->initialized = 1;
1294  if (s->has_alpha)
1295  avctx->pix_fmt = AV_PIX_FMT_YUVA420P;
1296  }
1297  s->lossless = 0;
1298 
1299  if (data_size > INT_MAX) {
1300  av_log(avctx, AV_LOG_ERROR, "unsupported chunk size\n");
1301  return AVERROR_PATCHWELCOME;
1302  }
1303 
1304  av_init_packet(&pkt);
1305  pkt.data = data_start;
1306  pkt.size = data_size;
1307 
1308  ret = ff_vp8_decode_frame(avctx, p, got_frame, &pkt);
1309  if (s->has_alpha) {
1310  ret = vp8_lossy_decode_alpha(avctx, p, s->alpha_data,
1311  s->alpha_data_size);
1312  if (ret < 0)
1313  return ret;
1314  }
1315  return ret;
1316 }
1317 
1318 static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
1319  AVPacket *avpkt)
1320 {
1321  AVFrame * const p = data;
1322  WebPContext *s = avctx->priv_data;
1323  GetByteContext gb;
1324  int ret;
1325  uint32_t chunk_type, chunk_size;
1326  int vp8x_flags = 0;
1327 
1328  s->avctx = avctx;
1329  s->width = 0;
1330  s->height = 0;
1331  *got_frame = 0;
1332  s->has_alpha = 0;
1333  bytestream2_init(&gb, avpkt->data, avpkt->size);
1334 
1335  if (bytestream2_get_bytes_left(&gb) < 12)
1336  return AVERROR_INVALIDDATA;
1337 
1338  if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
1339  av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
1340  return AVERROR_INVALIDDATA;
1341  }
1342 
1343  chunk_size = bytestream2_get_le32(&gb);
1344  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1345  return AVERROR_INVALIDDATA;
1346 
1347  if (bytestream2_get_le32(&gb) != MKTAG('W', 'E', 'B', 'P')) {
1348  av_log(avctx, AV_LOG_ERROR, "missing WEBP tag\n");
1349  return AVERROR_INVALIDDATA;
1350  }
1351 
1352  while (bytestream2_get_bytes_left(&gb) > 0) {
1353  char chunk_str[5] = { 0 };
1354 
1355  chunk_type = bytestream2_get_le32(&gb);
1356  chunk_size = bytestream2_get_le32(&gb);
1357  if (chunk_size == UINT32_MAX)
1358  return AVERROR_INVALIDDATA;
1359  chunk_size += chunk_size & 1;
1360 
1361  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1362  return AVERROR_INVALIDDATA;
1363 
1364  switch (chunk_type) {
1365  case MKTAG('V', 'P', '8', ' '):
1366  if (!*got_frame) {
1367  ret = vp8_lossy_decode_frame(avctx, p, got_frame,
1368  avpkt->data + bytestream2_tell(&gb),
1369  chunk_size);
1370  if (ret < 0)
1371  return ret;
1372  }
1373  bytestream2_skip(&gb, chunk_size);
1374  break;
1375  case MKTAG('V', 'P', '8', 'L'):
1376  if (!*got_frame) {
1377  ret = vp8_lossless_decode_frame(avctx, p, got_frame,
1378  avpkt->data + bytestream2_tell(&gb),
1379  chunk_size, 0);
1380  if (ret < 0)
1381  return ret;
1382  }
1383  bytestream2_skip(&gb, chunk_size);
1384  break;
1385  case MKTAG('V', 'P', '8', 'X'):
1386  vp8x_flags = bytestream2_get_byte(&gb);
1387  bytestream2_skip(&gb, 3);
1388  s->width = bytestream2_get_le24(&gb) + 1;
1389  s->height = bytestream2_get_le24(&gb) + 1;
1390  ret = av_image_check_size(s->width, s->height, 0, avctx);
1391  if (ret < 0)
1392  return ret;
1393  break;
1394  case MKTAG('A', 'L', 'P', 'H'): {
1395  int alpha_header, filter_m, compression;
1396 
1397  if (!(vp8x_flags & VP8X_FLAG_ALPHA)) {
1398  av_log(avctx, AV_LOG_WARNING,
1399  "ALPHA chunk present, but alpha bit not set in the "
1400  "VP8X header\n");
1401  }
1402  if (chunk_size == 0) {
1403  av_log(avctx, AV_LOG_ERROR, "invalid ALPHA chunk size\n");
1404  return AVERROR_INVALIDDATA;
1405  }
1406  alpha_header = bytestream2_get_byte(&gb);
1407  s->alpha_data = avpkt->data + bytestream2_tell(&gb);
1408  s->alpha_data_size = chunk_size - 1;
1410 
1411  filter_m = (alpha_header >> 2) & 0x03;
1412  compression = alpha_header & 0x03;
1413 
1414  if (compression > ALPHA_COMPRESSION_VP8L) {
1415  av_log(avctx, AV_LOG_VERBOSE,
1416  "skipping unsupported ALPHA chunk\n");
1417  } else {
1418  s->has_alpha = 1;
1419  s->alpha_compression = compression;
1420  s->alpha_filter = filter_m;
1421  }
1422 
1423  break;
1424  }
1425  case MKTAG('I', 'C', 'C', 'P'):
1426  case MKTAG('A', 'N', 'I', 'M'):
1427  case MKTAG('A', 'N', 'M', 'F'):
1428  case MKTAG('E', 'X', 'I', 'F'):
1429  case MKTAG('X', 'M', 'P', ' '):
1430  AV_WL32(chunk_str, chunk_type);
1431  av_log(avctx, AV_LOG_VERBOSE, "skipping unsupported chunk: %s\n",
1432  chunk_str);
1433  bytestream2_skip(&gb, chunk_size);
1434  break;
1435  default:
1436  AV_WL32(chunk_str, chunk_type);
1437  av_log(avctx, AV_LOG_VERBOSE, "skipping unknown chunk: %s\n",
1438  chunk_str);
1439  bytestream2_skip(&gb, chunk_size);
1440  break;
1441  }
1442  }
1443 
1444  if (!*got_frame) {
1445  av_log(avctx, AV_LOG_ERROR, "image data not found\n");
1446  return AVERROR_INVALIDDATA;
1447  }
1448 
1449  return avpkt->size;
1450 }
1451 
1453 {
1454  WebPContext *s = avctx->priv_data;
1455 
1456  if (s->initialized)
1457  return ff_vp8_decode_free(avctx);
1458 
1459  return 0;
1460 }
1461 
1463  .name = "webp",
1464  .long_name = NULL_IF_CONFIG_SMALL("WebP image"),
1465  .type = AVMEDIA_TYPE_VIDEO,
1466  .id = AV_CODEC_ID_WEBP,
1467  .priv_data_size = sizeof(WebPContext),
1470  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
1471 };
#define FFMAX(a, b)
Definition: common.h:55
int nb_huffman_groups
Definition: webp.c:177
#define extra_bits(eb)
Definition: intrax8.c:153
static int read_huffman_code_normal(WebPContext *s, HuffReader *hc, int alphabet_size)
Definition: webp.c:354
enum ImageRole role
Definition: webp.c:173
HuffReader * huffman_groups
Definition: webp.c:178
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:95
TransformType
Definition: webp.c:105
#define av_always_inline
Definition: attributes.h:40
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:862
ImageRole
Definition: webp.c:143
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:129
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:133
int initialized
Definition: webp.c:188
static int parse_transform_color_indexing(WebPContext *s)
Definition: webp.c:522
static HuffReader * get_huffman_group(WebPContext *s, ImageContext *img, int x, int y)
Definition: webp.c:557
HuffmanIndex
Definition: webp.c:129
static const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES]
Definition: webp.c:71
int size
Definition: avcodec.h:974
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:911
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:872
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1254
static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
Definition: webp.c:266
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:130
#define VLC_TYPE
Definition: get_bits.h:62
GetBitContext gb
Definition: webp.c:185
static int8_t ff_u8_to_s8(uint8_t a)
Definition: mathops.h:222
#define AV_COPY32(d, s)
Definition: intreadwrite.h:506
static const inv_predict_func inverse_predict[14]
Definition: webp.c:915
static int apply_color_indexing_transform(WebPContext *s)
Definition: webp.c:1020
AVCodec.
Definition: avcodec.h:2796
AlphaCompression
Definition: webp.c:93
static av_always_inline uint8_t clamp_add_subtract_half(int a, int b, int c)
Definition: webp.c:895
enum TransformType transforms[4]
Definition: webp.c:199
uint16_t simple_symbols[2]
Definition: webp.c:169
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:57
int height
Definition: webp.c:195
static int vp8_lossy_decode_alpha(AVCodecContext *avctx, AVFrame *p, uint8_t *data_start, unsigned int data_size)
Definition: webp.c:1230
#define NUM_LITERAL_CODES
Definition: webp.c:59
static av_always_inline void color_cache_put(ImageContext *img, uint32_t c)
Definition: webp.c:574
enum AlphaFilter alpha_filter
Definition: webp.c:191
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:852
uint8_t * alpha_data
Definition: webp.c:192
#define NUM_CODE_LENGTH_CODES
Definition: webp.c:57
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
int reduced_width
Definition: webp.c:200
int nb_huffman_groups
Definition: webp.c:201
uint8_t bits
Definition: crc.c:251
uint8_t
int nb_symbols
Definition: webp.c:168
Multithreading support functions.
#define b
Definition: input.c:52
int ff_vp8_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: vp8.c:2601
int simple
Definition: webp.c:167
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
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:886
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
#define NUM_SHORT_DISTANCES
Definition: webp.c:62
int pt
Definition: rtp.c:34
bitstream reader API header.
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:139
static int decode_entropy_image(WebPContext *s)
Definition: webp.c:456
#define AV_WB32(p, d)
Definition: intreadwrite.h:239
#define AV_WL32(p, d)
Definition: intreadwrite.h:255
#define r
Definition: input.c:51
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:784
static int apply_color_transform(WebPContext *s)
Definition: webp.c:981
#define VP8X_FLAG_ALPHA
Definition: webp.c:52
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:161
int width
width and height of the video frame
Definition: frame.h:174
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:186
static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: webp.c:1318
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:822
#define AVERROR(e)
Definition: error.h:43
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:104
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:159
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:69
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:258
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:149
Definition: graph2dot.c:49
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:798
VP8Context v
Definition: webp.c:184
static int vp8_lossy_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, uint8_t *data_start, unsigned int data_size)
Definition: webp.c:1283
#define CLOSE_READER(name, gb)
Definition: get_bits.h:141
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:1074
Libavcodec external API header.
enum AlphaCompression alpha_compression
Definition: webp.c:190
static void image_ctx_free(ImageContext *img)
Definition: webp.c:211
Definition: get_bits.h:64
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:176
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:234
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:222
#define PARSE_BLOCK_SIZE(w, h)
Definition: webp.c:450
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:196
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:791
void * av_malloc(size_t size) av_malloc_attrib 1(1)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
uint32_t * color_cache
Definition: webp.c:176
AlphaFilter
Definition: webp.c:98
AVFrame * frame
Definition: webp.c:174
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:182
int has_alpha
Definition: webp.c:189
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:188
PredictionMode
Definition: webp.c:112
#define AVERROR_PATCHWELCOME
Not yet implemented in Libav, patches welcome.
Definition: error.h:57
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:183
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:186
static const int8_t transform[32][32]
Definition: hevcdsp.c:25
NULL
Definition: eval.c:55
int alpha_data_size
Definition: webp.c:193
static int width
Definition: utils.c:156
#define av_cold
Definition: attributes.h:66
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:277
main external API structure.
Definition: avcodec.h:1050
static void(WINAPI *cond_broadcast)(pthread_cond_t *cond)
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:490
#define OPEN_READER(name, gb)
Definition: get_bits.h:127
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: get_bits.h:424
#define AVERROR_BUG
Bug detected, please report the issue.
Definition: error.h:60
static av_always_inline uint8_t color_transform_delta(uint8_t color_pred, uint8_t color)
Definition: webp.c:975
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:271
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:263
int index
Definition: gxfenc.c:72
AVCodec ff_webp_decoder
Definition: webp.c:1462
uint8_t * data
Definition: avcodec.h:973
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:805
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
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:777
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
#define MAX_HUFFMAN_CODE_LENGTH
Definition: webp.c:63
int size_reduction
Definition: webp.c:179
static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE]
Definition: webp.c:65
#define HUFFMAN_CODES_PER_META_CODE
Definition: webp.c:58
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
Definition: frame.c:175
void * priv_data
Definition: avcodec.h:1092
static void read_huffman_code_simple(WebPContext *s, HuffReader *hc)
Definition: webp.c:339
av_cold int ff_vp8_decode_init(AVCodecContext *avctx)
Definition: vp8.c:2677
#define MKTAG(a, b, c, d)
Definition: common.h:238
av_cold int ff_vp8_decode_free(AVCodecContext *avctx)
Definition: vp8.c:2615
static int parse_transform_predictor(WebPContext *s)
Definition: webp.c:490
#define GET_PIXEL(frame, x, y)
Definition: webp.c:205
static av_cold int webp_decode_close(AVCodecContext *avctx)
Definition: webp.c:1452
int nb_transforms
Definition: webp.c:198
common internal api header.
#define CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: avcodec.h:755
static int apply_subtract_green_transform(WebPContext *s)
Definition: webp.c:1005
int is_alpha_primary
Definition: webp.c:180
#define GET_PIXEL_COMP(frame, x, y, c)
Definition: webp.c:208
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:842
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:47
static const uint8_t color[]
Definition: log.c:55
#define AV_RB32(x)
Definition: intreadwrite.h:232
static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2]
Definition: webp.c:75
ImageContext image[IMAGE_ROLE_NB]
Definition: webp.c:202
int width
Definition: webp.c:194
static int apply_predictor_transform(WebPContext *s)
Definition: webp.c:944
float re
Definition: fft-test.c:69
VLC vlc
Definition: webp.c:166
int len
int color_cache_bits
Definition: webp.c:175
VLC_TYPE(* table)[2]
code, bits
Definition: get_bits.h:66
static int parse_transform_color(WebPContext *s)
Definition: webp.c:506
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:191
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:832
static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role, int w, int h)
Definition: webp.c:580
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:902
static void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.h:205
AVCodecContext * avctx
Definition: webp.c:187
int height
Definition: frame.h:174
static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
Definition: webp.c:1187
const uint8_t ff_reverse[256]
Definition: mathtables.c:72
#define FFABS(a)
Definition: common.h:52
int lossless
Definition: webp.c:196
static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
Definition: webp.c:922
This structure stores compressed data.
Definition: avcodec.h:950
AVFrame * alpha_frame
Definition: webp.c:186
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:333
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:812
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
#define NUM_LENGTH_CODES
Definition: webp.c:60
#define NUM_DISTANCE_CODES
Definition: webp.c:61