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 > 39) {
693  "distance prefix code too large: %d\n", prefix_code);
694  return AVERROR_INVALIDDATA;
695  }
696  if (prefix_code < 4) {
697  distance = prefix_code + 1;
698  } else {
699  int extra_bits = prefix_code - 2 >> 1;
700  int offset = 2 + (prefix_code & 1) << extra_bits;
701  distance = offset + get_bits(&s->gb, extra_bits) + 1;
702  }
703 
704  /* find reference location */
705  if (distance <= NUM_SHORT_DISTANCES) {
706  int xi = lz77_distance_offsets[distance - 1][0];
707  int yi = lz77_distance_offsets[distance - 1][1];
708  distance = FFMAX(1, xi + yi * width);
709  } else {
710  distance -= NUM_SHORT_DISTANCES;
711  }
712  ref_x = x;
713  ref_y = y;
714  if (distance <= x) {
715  ref_x -= distance;
716  distance = 0;
717  } else {
718  ref_x = 0;
719  distance -= x;
720  }
721  while (distance >= width) {
722  ref_y--;
723  distance -= width;
724  }
725  if (distance > 0) {
726  ref_x = width - distance;
727  ref_y--;
728  }
729  ref_x = FFMAX(0, ref_x);
730  ref_y = FFMAX(0, ref_y);
731 
732  /* copy pixels
733  * source and dest regions can overlap and wrap lines, so just
734  * copy per-pixel */
735  for (i = 0; i < length; i++) {
736  uint8_t *p_ref = GET_PIXEL(img->frame, ref_x, ref_y);
737  uint8_t *p = GET_PIXEL(img->frame, x, y);
738 
739  AV_COPY32(p, p_ref);
740  if (img->color_cache_bits)
741  color_cache_put(img, AV_RB32(p));
742  x++;
743  ref_x++;
744  if (x == width) {
745  x = 0;
746  y++;
747  }
748  if (ref_x == width) {
749  ref_x = 0;
750  ref_y++;
751  }
752  if (y == img->frame->height || ref_y == img->frame->height)
753  break;
754  }
755  } else {
756  /* read from color cache */
757  uint8_t *p = GET_PIXEL(img->frame, x, y);
758  int cache_idx = v - (NUM_LITERAL_CODES + NUM_LENGTH_CODES);
759 
760  if (!img->color_cache_bits) {
761  av_log(s->avctx, AV_LOG_ERROR, "color cache not found\n");
762  return AVERROR_INVALIDDATA;
763  }
764  if (cache_idx >= 1 << img->color_cache_bits) {
766  "color cache index out-of-bounds\n");
767  return AVERROR_INVALIDDATA;
768  }
769  AV_WB32(p, img->color_cache[cache_idx]);
770  x++;
771  if (x == width) {
772  x = 0;
773  y++;
774  }
775  }
776  }
777 
778  return 0;
779 }
780 
781 /* PRED_MODE_BLACK */
782 static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
783  const uint8_t *p_t, const uint8_t *p_tr)
784 {
785  AV_WB32(p, 0xFF000000);
786 }
787 
788 /* PRED_MODE_L */
789 static void inv_predict_1(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_COPY32(p, p_l);
793 }
794 
795 /* PRED_MODE_T */
796 static void inv_predict_2(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_t);
800 }
801 
802 /* PRED_MODE_TR */
803 static void inv_predict_3(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_tr);
807 }
808 
809 /* PRED_MODE_TL */
810 static void inv_predict_4(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_tl);
814 }
815 
816 /* PRED_MODE_AVG_T_AVG_L_TR */
817 static void inv_predict_5(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  p[0] = p_t[0] + (p_l[0] + p_tr[0] >> 1) >> 1;
821  p[1] = p_t[1] + (p_l[1] + p_tr[1] >> 1) >> 1;
822  p[2] = p_t[2] + (p_l[2] + p_tr[2] >> 1) >> 1;
823  p[3] = p_t[3] + (p_l[3] + p_tr[3] >> 1) >> 1;
824 }
825 
826 /* PRED_MODE_AVG_L_TL */
827 static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
828  const uint8_t *p_t, const uint8_t *p_tr)
829 {
830  p[0] = p_l[0] + p_tl[0] >> 1;
831  p[1] = p_l[1] + p_tl[1] >> 1;
832  p[2] = p_l[2] + p_tl[2] >> 1;
833  p[3] = p_l[3] + p_tl[3] >> 1;
834 }
835 
836 /* PRED_MODE_AVG_L_T */
837 static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
838  const uint8_t *p_t, const uint8_t *p_tr)
839 {
840  p[0] = p_l[0] + p_t[0] >> 1;
841  p[1] = p_l[1] + p_t[1] >> 1;
842  p[2] = p_l[2] + p_t[2] >> 1;
843  p[3] = p_l[3] + p_t[3] >> 1;
844 }
845 
846 /* PRED_MODE_AVG_TL_T */
847 static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
848  const uint8_t *p_t, const uint8_t *p_tr)
849 {
850  p[0] = p_tl[0] + p_t[0] >> 1;
851  p[1] = p_tl[1] + p_t[1] >> 1;
852  p[2] = p_tl[2] + p_t[2] >> 1;
853  p[3] = p_tl[3] + p_t[3] >> 1;
854 }
855 
856 /* PRED_MODE_AVG_T_TR */
857 static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
858  const uint8_t *p_t, const uint8_t *p_tr)
859 {
860  p[0] = p_t[0] + p_tr[0] >> 1;
861  p[1] = p_t[1] + p_tr[1] >> 1;
862  p[2] = p_t[2] + p_tr[2] >> 1;
863  p[3] = p_t[3] + p_tr[3] >> 1;
864 }
865 
866 /* PRED_MODE_AVG_AVG_L_TL_AVG_T_TR */
867 static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
868  const uint8_t *p_t, const uint8_t *p_tr)
869 {
870  p[0] = (p_l[0] + p_tl[0] >> 1) + (p_t[0] + p_tr[0] >> 1) >> 1;
871  p[1] = (p_l[1] + p_tl[1] >> 1) + (p_t[1] + p_tr[1] >> 1) >> 1;
872  p[2] = (p_l[2] + p_tl[2] >> 1) + (p_t[2] + p_tr[2] >> 1) >> 1;
873  p[3] = (p_l[3] + p_tl[3] >> 1) + (p_t[3] + p_tr[3] >> 1) >> 1;
874 }
875 
876 /* PRED_MODE_SELECT */
877 static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
878  const uint8_t *p_t, const uint8_t *p_tr)
879 {
880  int diff = (FFABS(p_l[0] - p_tl[0]) - FFABS(p_t[0] - p_tl[0])) +
881  (FFABS(p_l[1] - p_tl[1]) - FFABS(p_t[1] - p_tl[1])) +
882  (FFABS(p_l[2] - p_tl[2]) - FFABS(p_t[2] - p_tl[2])) +
883  (FFABS(p_l[3] - p_tl[3]) - FFABS(p_t[3] - p_tl[3]));
884  if (diff <= 0)
885  AV_COPY32(p, p_t);
886  else
887  AV_COPY32(p, p_l);
888 }
889 
890 /* PRED_MODE_ADD_SUBTRACT_FULL */
891 static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
892  const uint8_t *p_t, const uint8_t *p_tr)
893 {
894  p[0] = av_clip_uint8(p_l[0] + p_t[0] - p_tl[0]);
895  p[1] = av_clip_uint8(p_l[1] + p_t[1] - p_tl[1]);
896  p[2] = av_clip_uint8(p_l[2] + p_t[2] - p_tl[2]);
897  p[3] = av_clip_uint8(p_l[3] + p_t[3] - p_tl[3]);
898 }
899 
901 {
902  int d = a + b >> 1;
903  return av_clip_uint8(d + (d - c) / 2);
904 }
905 
906 /* PRED_MODE_ADD_SUBTRACT_HALF */
907 static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
908  const uint8_t *p_t, const uint8_t *p_tr)
909 {
910  p[0] = clamp_add_subtract_half(p_l[0], p_t[0], p_tl[0]);
911  p[1] = clamp_add_subtract_half(p_l[1], p_t[1], p_tl[1]);
912  p[2] = clamp_add_subtract_half(p_l[2], p_t[2], p_tl[2]);
913  p[3] = clamp_add_subtract_half(p_l[3], p_t[3], p_tl[3]);
914 }
915 
916 typedef void (*inv_predict_func)(uint8_t *p, const uint8_t *p_l,
917  const uint8_t *p_tl, const uint8_t *p_t,
918  const uint8_t *p_tr);
919 
920 static const inv_predict_func inverse_predict[14] = {
925 };
926 
927 static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
928 {
929  uint8_t *dec, *p_l, *p_tl, *p_t, *p_tr;
930  uint8_t p[4];
931 
932  dec = GET_PIXEL(frame, x, y);
933  p_l = GET_PIXEL(frame, x - 1, y);
934  p_tl = GET_PIXEL(frame, x - 1, y - 1);
935  p_t = GET_PIXEL(frame, x, y - 1);
936  if (x == frame->width - 1)
937  p_tr = GET_PIXEL(frame, 0, y);
938  else
939  p_tr = GET_PIXEL(frame, x + 1, y - 1);
940 
941  inverse_predict[m](p, p_l, p_tl, p_t, p_tr);
942 
943  dec[0] += p[0];
944  dec[1] += p[1];
945  dec[2] += p[2];
946  dec[3] += p[3];
947 }
948 
950 {
951  ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
953  int x, y;
954 
955  for (y = 0; y < img->frame->height; y++) {
956  for (x = 0; x < img->frame->width; x++) {
957  int tx = x >> pimg->size_reduction;
958  int ty = y >> pimg->size_reduction;
959  enum PredictionMode m = GET_PIXEL_COMP(pimg->frame, tx, ty, 2);
960 
961  if (x == 0) {
962  if (y == 0)
963  m = PRED_MODE_BLACK;
964  else
965  m = PRED_MODE_T;
966  } else if (y == 0)
967  m = PRED_MODE_L;
968 
969  if (m > 13) {
971  "invalid predictor mode: %d\n", m);
972  return AVERROR_INVALIDDATA;
973  }
974  inverse_prediction(img->frame, m, x, y);
975  }
976  }
977  return 0;
978 }
979 
981  uint8_t color)
982 {
983  return (int)ff_u8_to_s8(color_pred) * ff_u8_to_s8(color) >> 5;
984 }
985 
987 {
988  ImageContext *img, *cimg;
989  int x, y, cx, cy;
990  uint8_t *p, *cp;
991 
992  img = &s->image[IMAGE_ROLE_ARGB];
993  cimg = &s->image[IMAGE_ROLE_COLOR_TRANSFORM];
994 
995  for (y = 0; y < img->frame->height; y++) {
996  for (x = 0; x < img->frame->width; x++) {
997  cx = x >> cimg->size_reduction;
998  cy = y >> cimg->size_reduction;
999  cp = GET_PIXEL(cimg->frame, cx, cy);
1000  p = GET_PIXEL(img->frame, x, y);
1001 
1002  p[1] += color_transform_delta(cp[3], p[2]);
1003  p[3] += color_transform_delta(cp[2], p[2]) +
1004  color_transform_delta(cp[1], p[1]);
1005  }
1006  }
1007  return 0;
1008 }
1009 
1011 {
1012  int x, y;
1013  ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
1014 
1015  for (y = 0; y < img->frame->height; y++) {
1016  for (x = 0; x < img->frame->width; x++) {
1017  uint8_t *p = GET_PIXEL(img->frame, x, y);
1018  p[1] += p[2];
1019  p[3] += p[2];
1020  }
1021  }
1022  return 0;
1023 }
1024 
1026 {
1027  ImageContext *img;
1028  ImageContext *pal;
1029  int i, x, y;
1030  uint8_t *p, *pi;
1031 
1032  img = &s->image[IMAGE_ROLE_ARGB];
1033  pal = &s->image[IMAGE_ROLE_COLOR_INDEXING];
1034 
1035  if (pal->size_reduction > 0) {
1036  GetBitContext gb_g;
1037  uint8_t *line;
1038  int pixel_bits = 8 >> pal->size_reduction;
1039 
1040  line = av_malloc(img->frame->linesize[0]);
1041  if (!line)
1042  return AVERROR(ENOMEM);
1043 
1044  for (y = 0; y < img->frame->height; y++) {
1045  p = GET_PIXEL(img->frame, 0, y);
1046  memcpy(line, p, img->frame->linesize[0]);
1047  init_get_bits(&gb_g, line, img->frame->linesize[0] * 8);
1048  skip_bits(&gb_g, 16);
1049  i = 0;
1050  for (x = 0; x < img->frame->width; x++) {
1051  p = GET_PIXEL(img->frame, x, y);
1052  p[2] = get_bits(&gb_g, pixel_bits);
1053  i++;
1054  if (i == 1 << pal->size_reduction) {
1055  skip_bits(&gb_g, 24);
1056  i = 0;
1057  }
1058  }
1059  }
1060  av_free(line);
1061  }
1062 
1063  for (y = 0; y < img->frame->height; y++) {
1064  for (x = 0; x < img->frame->width; x++) {
1065  p = GET_PIXEL(img->frame, x, y);
1066  i = p[2];
1067  if (i >= pal->frame->width) {
1068  av_log(s->avctx, AV_LOG_ERROR, "invalid palette index %d\n", i);
1069  return AVERROR_INVALIDDATA;
1070  }
1071  pi = GET_PIXEL(pal->frame, i, 0);
1072  AV_COPY32(p, pi);
1073  }
1074  }
1075 
1076  return 0;
1077 }
1078 
1080  int *got_frame, uint8_t *data_start,
1081  unsigned int data_size, int is_alpha_chunk)
1082 {
1083  WebPContext *s = avctx->priv_data;
1084  int w, h, ret, i;
1085 
1086  if (!is_alpha_chunk) {
1087  s->lossless = 1;
1088  avctx->pix_fmt = AV_PIX_FMT_ARGB;
1089  }
1090 
1091  ret = init_get_bits(&s->gb, data_start, data_size * 8);
1092  if (ret < 0)
1093  return ret;
1094 
1095  if (!is_alpha_chunk) {
1096  if (get_bits(&s->gb, 8) != 0x2F) {
1097  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless signature\n");
1098  return AVERROR_INVALIDDATA;
1099  }
1100 
1101  w = get_bits(&s->gb, 14) + 1;
1102  h = get_bits(&s->gb, 14) + 1;
1103  if (s->width && s->width != w) {
1104  av_log(avctx, AV_LOG_WARNING, "Width mismatch. %d != %d\n",
1105  s->width, w);
1106  }
1107  s->width = w;
1108  if (s->height && s->height != h) {
1109  av_log(avctx, AV_LOG_WARNING, "Height mismatch. %d != %d\n",
1110  s->width, w);
1111  }
1112  s->height = h;
1113 
1114  ret = ff_set_dimensions(avctx, s->width, s->height);
1115  if (ret < 0)
1116  return ret;
1117 
1118  s->has_alpha = get_bits1(&s->gb);
1119 
1120  if (get_bits(&s->gb, 3) != 0x0) {
1121  av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless version\n");
1122  return AVERROR_INVALIDDATA;
1123  }
1124  } else {
1125  if (!s->width || !s->height)
1126  return AVERROR_BUG;
1127  w = s->width;
1128  h = s->height;
1129  }
1130 
1131  /* parse transformations */
1132  s->nb_transforms = 0;
1133  s->reduced_width = 0;
1134  while (get_bits1(&s->gb)) {
1135  enum TransformType transform = get_bits(&s->gb, 2);
1136  s->transforms[s->nb_transforms++] = transform;
1137  switch (transform) {
1138  case PREDICTOR_TRANSFORM:
1139  ret = parse_transform_predictor(s);
1140  break;
1141  case COLOR_TRANSFORM:
1142  ret = parse_transform_color(s);
1143  break;
1146  break;
1147  }
1148  if (ret < 0)
1149  goto free_and_return;
1150  }
1151 
1152  /* decode primary image */
1153  s->image[IMAGE_ROLE_ARGB].frame = p;
1154  if (is_alpha_chunk)
1157  if (ret < 0)
1158  goto free_and_return;
1159 
1160  /* apply transformations */
1161  for (i = s->nb_transforms - 1; i >= 0; i--) {
1162  switch (s->transforms[i]) {
1163  case PREDICTOR_TRANSFORM:
1164  ret = apply_predictor_transform(s);
1165  break;
1166  case COLOR_TRANSFORM:
1167  ret = apply_color_transform(s);
1168  break;
1169  case SUBTRACT_GREEN:
1171  break;
1174  break;
1175  }
1176  if (ret < 0)
1177  goto free_and_return;
1178  }
1179 
1180  *got_frame = 1;
1182  p->key_frame = 1;
1183  ret = data_size;
1184 
1185 free_and_return:
1186  for (i = 0; i < IMAGE_ROLE_NB; i++)
1187  image_ctx_free(&s->image[i]);
1188 
1189  return ret;
1190 }
1191 
1192 static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
1193 {
1194  int x, y, ls;
1195  uint8_t *dec;
1196 
1197  ls = frame->linesize[3];
1198 
1199  /* filter first row using horizontal filter */
1200  dec = frame->data[3] + 1;
1201  for (x = 1; x < frame->width; x++, dec++)
1202  *dec += *(dec - 1);
1203 
1204  /* filter first column using vertical filter */
1205  dec = frame->data[3] + ls;
1206  for (y = 1; y < frame->height; y++, dec += ls)
1207  *dec += *(dec - ls);
1208 
1209  /* filter the rest using the specified filter */
1210  switch (m) {
1212  for (y = 1; y < frame->height; y++) {
1213  dec = frame->data[3] + y * ls + 1;
1214  for (x = 1; x < frame->width; x++, dec++)
1215  *dec += *(dec - 1);
1216  }
1217  break;
1218  case ALPHA_FILTER_VERTICAL:
1219  for (y = 1; y < frame->height; y++) {
1220  dec = frame->data[3] + y * ls + 1;
1221  for (x = 1; x < frame->width; x++, dec++)
1222  *dec += *(dec - ls);
1223  }
1224  break;
1225  case ALPHA_FILTER_GRADIENT:
1226  for (y = 1; y < frame->height; y++) {
1227  dec = frame->data[3] + y * ls + 1;
1228  for (x = 1; x < frame->width; x++, dec++)
1229  dec[0] += av_clip_uint8(*(dec - 1) + *(dec - ls) - *(dec - ls - 1));
1230  }
1231  break;
1232  }
1233 }
1234 
1236  uint8_t *data_start,
1237  unsigned int data_size)
1238 {
1239  WebPContext *s = avctx->priv_data;
1240  int x, y, ret;
1241 
1243  GetByteContext gb;
1244 
1245  bytestream2_init(&gb, data_start, data_size);
1246  for (y = 0; y < s->height; y++)
1247  bytestream2_get_buffer(&gb, p->data[3] + p->linesize[3] * y,
1248  s->width);
1249  } else if (s->alpha_compression == ALPHA_COMPRESSION_VP8L) {
1250  uint8_t *ap, *pp;
1251  int alpha_got_frame = 0;
1252 
1253  s->alpha_frame = av_frame_alloc();
1254  if (!s->alpha_frame)
1255  return AVERROR(ENOMEM);
1256 
1257  ret = vp8_lossless_decode_frame(avctx, s->alpha_frame, &alpha_got_frame,
1258  data_start, data_size, 1);
1259  if (ret < 0) {
1261  return ret;
1262  }
1263  if (!alpha_got_frame) {
1265  return AVERROR_INVALIDDATA;
1266  }
1267 
1268  /* copy green component of alpha image to alpha plane of primary image */
1269  for (y = 0; y < s->height; y++) {
1270  ap = GET_PIXEL(s->alpha_frame, 0, y) + 2;
1271  pp = p->data[3] + p->linesize[3] * y;
1272  for (x = 0; x < s->width; x++) {
1273  *pp = *ap;
1274  pp++;
1275  ap += 4;
1276  }
1277  }
1279  }
1280 
1281  /* apply alpha filtering */
1282  if (s->alpha_filter)
1284 
1285  return 0;
1286 }
1287 
1289  int *got_frame, uint8_t *data_start,
1290  unsigned int data_size)
1291 {
1292  WebPContext *s = avctx->priv_data;
1293  AVPacket pkt;
1294  int ret;
1295 
1296  if (!s->initialized) {
1297  ff_vp8_decode_init(avctx);
1298  s->initialized = 1;
1299  if (s->has_alpha)
1300  avctx->pix_fmt = AV_PIX_FMT_YUVA420P;
1301  }
1302  s->lossless = 0;
1303 
1304  if (data_size > INT_MAX) {
1305  av_log(avctx, AV_LOG_ERROR, "unsupported chunk size\n");
1306  return AVERROR_PATCHWELCOME;
1307  }
1308 
1309  av_init_packet(&pkt);
1310  pkt.data = data_start;
1311  pkt.size = data_size;
1312 
1313  ret = ff_vp8_decode_frame(avctx, p, got_frame, &pkt);
1314  if (s->has_alpha) {
1315  ret = vp8_lossy_decode_alpha(avctx, p, s->alpha_data,
1316  s->alpha_data_size);
1317  if (ret < 0)
1318  return ret;
1319  }
1320  return ret;
1321 }
1322 
1323 static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
1324  AVPacket *avpkt)
1325 {
1326  AVFrame * const p = data;
1327  WebPContext *s = avctx->priv_data;
1328  GetByteContext gb;
1329  int ret;
1330  uint32_t chunk_type, chunk_size;
1331  int vp8x_flags = 0;
1332 
1333  s->avctx = avctx;
1334  s->width = 0;
1335  s->height = 0;
1336  *got_frame = 0;
1337  s->has_alpha = 0;
1338  bytestream2_init(&gb, avpkt->data, avpkt->size);
1339 
1340  if (bytestream2_get_bytes_left(&gb) < 12)
1341  return AVERROR_INVALIDDATA;
1342 
1343  if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
1344  av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
1345  return AVERROR_INVALIDDATA;
1346  }
1347 
1348  chunk_size = bytestream2_get_le32(&gb);
1349  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1350  return AVERROR_INVALIDDATA;
1351 
1352  if (bytestream2_get_le32(&gb) != MKTAG('W', 'E', 'B', 'P')) {
1353  av_log(avctx, AV_LOG_ERROR, "missing WEBP tag\n");
1354  return AVERROR_INVALIDDATA;
1355  }
1356 
1357  while (bytestream2_get_bytes_left(&gb) > 0) {
1358  char chunk_str[5] = { 0 };
1359 
1360  chunk_type = bytestream2_get_le32(&gb);
1361  chunk_size = bytestream2_get_le32(&gb);
1362  if (chunk_size == UINT32_MAX)
1363  return AVERROR_INVALIDDATA;
1364  chunk_size += chunk_size & 1;
1365 
1366  if (bytestream2_get_bytes_left(&gb) < chunk_size)
1367  return AVERROR_INVALIDDATA;
1368 
1369  switch (chunk_type) {
1370  case MKTAG('V', 'P', '8', ' '):
1371  if (!*got_frame) {
1372  ret = vp8_lossy_decode_frame(avctx, p, got_frame,
1373  avpkt->data + bytestream2_tell(&gb),
1374  chunk_size);
1375  if (ret < 0)
1376  return ret;
1377  }
1378  bytestream2_skip(&gb, chunk_size);
1379  break;
1380  case MKTAG('V', 'P', '8', 'L'):
1381  if (!*got_frame) {
1382  ret = vp8_lossless_decode_frame(avctx, p, got_frame,
1383  avpkt->data + bytestream2_tell(&gb),
1384  chunk_size, 0);
1385  if (ret < 0)
1386  return ret;
1387  }
1388  bytestream2_skip(&gb, chunk_size);
1389  break;
1390  case MKTAG('V', 'P', '8', 'X'):
1391  vp8x_flags = bytestream2_get_byte(&gb);
1392  bytestream2_skip(&gb, 3);
1393  s->width = bytestream2_get_le24(&gb) + 1;
1394  s->height = bytestream2_get_le24(&gb) + 1;
1395  ret = av_image_check_size(s->width, s->height, 0, avctx);
1396  if (ret < 0)
1397  return ret;
1398  break;
1399  case MKTAG('A', 'L', 'P', 'H'): {
1400  int alpha_header, filter_m, compression;
1401 
1402  if (!(vp8x_flags & VP8X_FLAG_ALPHA)) {
1403  av_log(avctx, AV_LOG_WARNING,
1404  "ALPHA chunk present, but alpha bit not set in the "
1405  "VP8X header\n");
1406  }
1407  if (chunk_size == 0) {
1408  av_log(avctx, AV_LOG_ERROR, "invalid ALPHA chunk size\n");
1409  return AVERROR_INVALIDDATA;
1410  }
1411  alpha_header = bytestream2_get_byte(&gb);
1412  s->alpha_data = avpkt->data + bytestream2_tell(&gb);
1413  s->alpha_data_size = chunk_size - 1;
1415 
1416  filter_m = (alpha_header >> 2) & 0x03;
1417  compression = alpha_header & 0x03;
1418 
1419  if (compression > ALPHA_COMPRESSION_VP8L) {
1420  av_log(avctx, AV_LOG_VERBOSE,
1421  "skipping unsupported ALPHA chunk\n");
1422  } else {
1423  s->has_alpha = 1;
1424  s->alpha_compression = compression;
1425  s->alpha_filter = filter_m;
1426  }
1427 
1428  break;
1429  }
1430  case MKTAG('I', 'C', 'C', 'P'):
1431  case MKTAG('A', 'N', 'I', 'M'):
1432  case MKTAG('A', 'N', 'M', 'F'):
1433  case MKTAG('E', 'X', 'I', 'F'):
1434  case MKTAG('X', 'M', 'P', ' '):
1435  AV_WL32(chunk_str, chunk_type);
1436  av_log(avctx, AV_LOG_VERBOSE, "skipping unsupported chunk: %s\n",
1437  chunk_str);
1438  bytestream2_skip(&gb, chunk_size);
1439  break;
1440  default:
1441  AV_WL32(chunk_str, chunk_type);
1442  av_log(avctx, AV_LOG_VERBOSE, "skipping unknown chunk: %s\n",
1443  chunk_str);
1444  bytestream2_skip(&gb, chunk_size);
1445  break;
1446  }
1447  }
1448 
1449  if (!*got_frame) {
1450  av_log(avctx, AV_LOG_ERROR, "image data not found\n");
1451  return AVERROR_INVALIDDATA;
1452  }
1453 
1454  return avpkt->size;
1455 }
1456 
1458 {
1459  WebPContext *s = avctx->priv_data;
1460 
1461  if (s->initialized)
1462  return ff_vp8_decode_free(avctx);
1463 
1464  return 0;
1465 }
1466 
1468  .name = "webp",
1469  .long_name = NULL_IF_CONFIG_SMALL("WebP image"),
1470  .type = AVMEDIA_TYPE_VIDEO,
1471  .id = AV_CODEC_ID_WEBP,
1472  .priv_data_size = sizeof(WebPContext),
1475  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
1476 };
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
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
#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
TransformType
Definition: webp.c:105
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:867
ImageRole
Definition: webp.c:143
misc image utilities
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
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:877
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
static const inv_predict_func inverse_predict[14]
Definition: webp.c:920
static int apply_color_indexing_transform(WebPContext *s)
Definition: webp.c:1025
AVCodec.
Definition: avcodec.h:2796
#define AV_COPY32(d, s)
Definition: intreadwrite.h:506
AlphaCompression
Definition: webp.c:93
static av_always_inline uint8_t clamp_add_subtract_half(int a, int b, int c)
Definition: webp.c:900
enum TransformType transforms[4]
Definition: webp.c:199
uint16_t simple_symbols[2]
Definition: webp.c:169
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:1235
#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:857
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
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:104
int nb_huffman_groups
Definition: webp.c:201
uint8_t bits
Definition: crc.c:251
uint8_t
#define av_cold
Definition: attributes.h:66
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:57
#define AV_WB32(p, d)
Definition: intreadwrite.h:239
int nb_symbols
Definition: webp.c:168
#define AV_RB32
Definition: intreadwrite.h:130
Multithreading support functions.
#define b
Definition: input.c:52
#define AV_WL32(p, d)
Definition: intreadwrite.h:255
int ff_vp8_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: vp8.c:2601
int simple
Definition: webp.c:167
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:891
#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
uint8_t * data
Definition: avcodec.h:973
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 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:789
static int apply_color_transform(WebPContext *s)
Definition: webp.c:986
#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:1323
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:827
#define AVERROR(e)
Definition: error.h:43
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
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
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:803
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:1288
#define CLOSE_READER(name, gb)
Definition: get_bits.h:141
#define FFMAX(a, b)
Definition: common.h:55
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:1079
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:95
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:796
uint32_t * color_cache
Definition: webp.c:176
AlphaFilter
Definition: webp.c:98
#define FFABS(a)
Definition: common.h:52
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
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:916
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
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
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:980
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:1467
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:810
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:782
#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
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
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
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:1457
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:1010
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:847
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
void * priv_data
Definition: avcodec.h:1092
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:949
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:837
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:907
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:1192
#define av_always_inline
Definition: attributes.h:40
const uint8_t ff_reverse[256]
Definition: mathtables.c:72
int lossless
Definition: webp.c:196
static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
Definition: webp.c:927
#define MKTAG(a, b, c, d)
Definition: common.h:238
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:817
#define NUM_LENGTH_CODES
Definition: webp.c:60
#define NUM_DISTANCE_CODES
Definition: webp.c:61