2 * WebP (.webp) image decoder
3 * Copyright (c) 2013 Aneesh Dogra <aneesh@sugarlabs.org>
4 * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 * @author Aneesh Dogra <aneesh@sugarlabs.org>
28 * Container and Lossy decoding
30 * @author Justin Ruggles <justin.ruggles@gmail.com>
32 * Compressed alpha for lossy
34 * @author James Almer <jamrial@gmail.com>
43 #include "libavutil/imgutils.h"
45 #define BITSTREAM_READER_LE
47 #include "bytestream.h"
54 #define VP8X_FLAG_ANIMATION 0x02
55 #define VP8X_FLAG_XMP_METADATA 0x04
56 #define VP8X_FLAG_EXIF_METADATA 0x08
57 #define VP8X_FLAG_ALPHA 0x10
58 #define VP8X_FLAG_ICC 0x20
60 #define MAX_PALETTE_SIZE 256
61 #define MAX_CACHE_BITS 11
62 #define NUM_CODE_LENGTH_CODES 19
63 #define HUFFMAN_CODES_PER_META_CODE 5
64 #define NUM_LITERAL_CODES 256
65 #define NUM_LENGTH_CODES 24
66 #define NUM_DISTANCE_CODES 40
67 #define NUM_SHORT_DISTANCES 120
68 #define MAX_HUFFMAN_CODE_LENGTH 15
70 static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE] = {
71 NUM_LITERAL_CODES + NUM_LENGTH_CODES,
72 NUM_LITERAL_CODES, NUM_LITERAL_CODES, NUM_LITERAL_CODES,
76 static const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES] = {
77 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
80 static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2] = {
81 { 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 },
82 { 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 },
83 { 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 },
84 { 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 },
85 { 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 },
86 { 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 },
87 { 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 },
88 { 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 },
89 { 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 },
90 { 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 },
91 { 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 },
92 { 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 },
93 { 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 },
94 { -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 },
95 { -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 }
98 enum AlphaCompression {
99 ALPHA_COMPRESSION_NONE,
100 ALPHA_COMPRESSION_VP8L,
105 ALPHA_FILTER_HORIZONTAL,
106 ALPHA_FILTER_VERTICAL,
107 ALPHA_FILTER_GRADIENT,
111 PREDICTOR_TRANSFORM = 0,
114 COLOR_INDEXING_TRANSFORM = 3,
117 enum PredictionMode {
123 PRED_MODE_AVG_T_AVG_L_TR,
128 PRED_MODE_AVG_AVG_L_TL_AVG_T_TR,
130 PRED_MODE_ADD_SUBTRACT_FULL,
131 PRED_MODE_ADD_SUBTRACT_HALF,
142 /* The structure of WebP lossless is an optional series of transformation data,
143 * followed by the primary image. The primary image also optionally contains
144 * an entropy group mapping if there are multiple entropy groups. There is a
145 * basic image type called an "entropy coded image" that is used for all of
146 * these. The type of each entropy coded image is referred to by the
147 * specification as its role. */
149 /* Primary Image: Stores the actual pixels of the image. */
152 /* Entropy Image: Defines which Huffman group to use for different areas of
153 * the primary image. */
156 /* Predictors: Defines which predictor type to use for different areas of
157 * the primary image. */
158 IMAGE_ROLE_PREDICTOR,
160 /* Color Transform Data: Defines the color transformation for different
161 * areas of the primary image. */
162 IMAGE_ROLE_COLOR_TRANSFORM,
164 /* Color Index: Stored as an image of height == 1. */
165 IMAGE_ROLE_COLOR_INDEXING,
170 typedef struct HuffReader {
171 VLC vlc; /* Huffman decoder context */
172 int simple; /* whether to use simple mode */
173 int nb_symbols; /* number of coded symbols */
174 uint16_t simple_symbols[2]; /* symbols for simple mode */
177 typedef struct ImageContext {
178 enum ImageRole role; /* role of this image */
179 AVFrame *frame; /* AVFrame for data */
180 int color_cache_bits; /* color cache size, log2 */
181 uint32_t *color_cache; /* color cache data */
182 int nb_huffman_groups; /* number of huffman groups */
183 HuffReader *huffman_groups; /* reader for each huffman group */
184 int size_reduction; /* relative size compared to primary image, log2 */
185 int is_alpha_primary;
188 typedef struct WebPContext {
189 VP8Context v; /* VP8 Context used for lossy decoding */
190 GetBitContext gb; /* bitstream reader for main image chunk */
191 AVFrame *alpha_frame; /* AVFrame for alpha data decompressed from VP8L */
192 AVCodecContext *avctx; /* parent AVCodecContext */
193 int initialized; /* set once the VP8 context is initialized */
194 int has_alpha; /* has a separate alpha chunk */
195 enum AlphaCompression alpha_compression; /* compression type for alpha chunk */
196 enum AlphaFilter alpha_filter; /* filtering method for alpha chunk */
197 uint8_t *alpha_data; /* alpha chunk data */
198 int alpha_data_size; /* alpha chunk data size */
199 int has_exif; /* set after an EXIF chunk has been processed */
200 int has_iccp; /* set after an ICCP chunk has been processed */
201 int width; /* image width */
202 int height; /* image height */
203 int lossless; /* indicates lossless or lossy */
205 int nb_transforms; /* number of transforms */
206 enum TransformType transforms[4]; /* transformations used in the image, in order */
207 int reduced_width; /* reduced width for index image, if applicable */
208 int nb_huffman_groups; /* number of huffman groups in the primary image */
209 ImageContext image[IMAGE_ROLE_NB]; /* image context for each role */
212 #define GET_PIXEL(frame, x, y) \
213 ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x))
215 #define GET_PIXEL_COMP(frame, x, y, c) \
216 (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c))
218 static void image_ctx_free(ImageContext *img)
222 av_free(img->color_cache);
223 if (img->role != IMAGE_ROLE_ARGB && !img->is_alpha_primary)
224 av_frame_free(&img->frame);
225 if (img->huffman_groups) {
226 for (i = 0; i < img->nb_huffman_groups; i++) {
227 for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++)
228 ff_free_vlc(&img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE + j].vlc);
230 av_free(img->huffman_groups);
232 memset(img, 0, sizeof(*img));
235 static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
238 if (r->nb_symbols == 1)
239 return r->simple_symbols[0];
241 return r->simple_symbols[get_bits1(gb)];
243 return get_vlc2(gb, r->vlc.table, 8, 2);
246 static int huff_reader_build_canonical(HuffReader *r, const uint8_t *code_lengths,
249 int len = 0, sym, code = 0, ret;
250 int max_code_length = 0;
253 /* special-case 1 symbol since the vlc reader cannot handle it */
254 for (sym = 0; sym < alphabet_size; sym++) {
255 if (code_lengths[sym] > 0) {
264 r->simple_symbols[0] = code;
269 for (sym = 0; sym < alphabet_size; sym++)
270 max_code_length = FFMAX(max_code_length, code_lengths[sym]);
272 if (max_code_length == 0 || max_code_length > MAX_HUFFMAN_CODE_LENGTH)
273 return AVERROR(EINVAL);
275 codes = av_malloc_array(alphabet_size, sizeof(*codes));
277 return AVERROR(ENOMEM);
281 for (len = 1; len <= max_code_length; len++) {
282 for (sym = 0; sym < alphabet_size; sym++) {
283 if (code_lengths[sym] != len)
290 if (!r->nb_symbols) {
292 return AVERROR_INVALIDDATA;
295 ret = init_vlc(&r->vlc, 8, alphabet_size,
296 code_lengths, sizeof(*code_lengths), sizeof(*code_lengths),
297 codes, sizeof(*codes), sizeof(*codes), INIT_VLC_OUTPUT_LE);
308 static void read_huffman_code_simple(WebPContext *s, HuffReader *hc)
310 hc->nb_symbols = get_bits1(&s->gb) + 1;
312 if (get_bits1(&s->gb))
313 hc->simple_symbols[0] = get_bits(&s->gb, 8);
315 hc->simple_symbols[0] = get_bits1(&s->gb);
317 if (hc->nb_symbols == 2)
318 hc->simple_symbols[1] = get_bits(&s->gb, 8);
323 static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
326 HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
327 uint8_t *code_lengths;
328 uint8_t code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
329 int i, symbol, max_symbol, prev_code_len, ret;
330 int num_codes = 4 + get_bits(&s->gb, 4);
332 av_assert1(num_codes <= NUM_CODE_LENGTH_CODES);
334 for (i = 0; i < num_codes; i++)
335 code_length_code_lengths[code_length_code_order[i]] = get_bits(&s->gb, 3);
337 ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths,
338 NUM_CODE_LENGTH_CODES);
342 code_lengths = av_mallocz(alphabet_size);
344 ret = AVERROR(ENOMEM);
348 if (get_bits1(&s->gb)) {
349 int bits = 2 + 2 * get_bits(&s->gb, 3);
350 max_symbol = 2 + get_bits(&s->gb, bits);
351 if (max_symbol > alphabet_size) {
352 av_log(s->avctx, AV_LOG_ERROR, "max symbol %d > alphabet size %d\n",
353 max_symbol, alphabet_size);
354 ret = AVERROR_INVALIDDATA;
358 max_symbol = alphabet_size;
363 while (symbol < alphabet_size) {
368 code_len = huff_reader_get_symbol(&code_len_hc, &s->gb);
370 /* Code length code [0..15] indicates literal code lengths. */
371 code_lengths[symbol++] = code_len;
373 prev_code_len = code_len;
375 int repeat = 0, length = 0;
378 /* Code 16 repeats the previous non-zero value [3..6] times,
379 * i.e., 3 + ReadBits(2) times. If code 16 is used before a
380 * non-zero value has been emitted, a value of 8 is repeated. */
381 repeat = 3 + get_bits(&s->gb, 2);
382 length = prev_code_len;
385 /* Code 17 emits a streak of zeros [3..10], i.e.,
386 * 3 + ReadBits(3) times. */
387 repeat = 3 + get_bits(&s->gb, 3);
390 /* Code 18 emits a streak of zeros of length [11..138], i.e.,
391 * 11 + ReadBits(7) times. */
392 repeat = 11 + get_bits(&s->gb, 7);
395 if (symbol + repeat > alphabet_size) {
396 av_log(s->avctx, AV_LOG_ERROR,
397 "invalid symbol %d + repeat %d > alphabet size %d\n",
398 symbol, repeat, alphabet_size);
399 ret = AVERROR_INVALIDDATA;
403 code_lengths[symbol++] = length;
407 ret = huff_reader_build_canonical(hc, code_lengths, alphabet_size);
410 ff_free_vlc(&code_len_hc.vlc);
411 av_free(code_lengths);
415 static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
418 #define PARSE_BLOCK_SIZE(w, h) do { \
419 block_bits = get_bits(&s->gb, 3) + 2; \
420 blocks_w = FFALIGN((w), 1 << block_bits) >> block_bits; \
421 blocks_h = FFALIGN((h), 1 << block_bits) >> block_bits; \
424 static int decode_entropy_image(WebPContext *s)
427 int ret, block_bits, width, blocks_w, blocks_h, x, y, max;
430 if (s->reduced_width > 0)
431 width = s->reduced_width;
433 PARSE_BLOCK_SIZE(width, s->height);
435 ret = decode_entropy_coded_image(s, IMAGE_ROLE_ENTROPY, blocks_w, blocks_h);
439 img = &s->image[IMAGE_ROLE_ENTROPY];
440 img->size_reduction = block_bits;
442 /* the number of huffman groups is determined by the maximum group number
443 * coded in the entropy image */
445 for (y = 0; y < img->frame->height; y++) {
446 for (x = 0; x < img->frame->width; x++) {
447 int p0 = GET_PIXEL_COMP(img->frame, x, y, 1);
448 int p1 = GET_PIXEL_COMP(img->frame, x, y, 2);
449 int p = p0 << 8 | p1;
453 s->nb_huffman_groups = max + 1;
458 static int parse_transform_predictor(WebPContext *s)
460 int block_bits, blocks_w, blocks_h, ret;
462 PARSE_BLOCK_SIZE(s->width, s->height);
464 ret = decode_entropy_coded_image(s, IMAGE_ROLE_PREDICTOR, blocks_w,
469 s->image[IMAGE_ROLE_PREDICTOR].size_reduction = block_bits;
474 static int parse_transform_color(WebPContext *s)
476 int block_bits, blocks_w, blocks_h, ret;
478 PARSE_BLOCK_SIZE(s->width, s->height);
480 ret = decode_entropy_coded_image(s, IMAGE_ROLE_COLOR_TRANSFORM, blocks_w,
485 s->image[IMAGE_ROLE_COLOR_TRANSFORM].size_reduction = block_bits;
490 static int parse_transform_color_indexing(WebPContext *s)
493 int width_bits, index_size, ret, x;
496 index_size = get_bits(&s->gb, 8) + 1;
500 else if (index_size <= 4)
502 else if (index_size <= 16)
507 ret = decode_entropy_coded_image(s, IMAGE_ROLE_COLOR_INDEXING,
512 img = &s->image[IMAGE_ROLE_COLOR_INDEXING];
513 img->size_reduction = width_bits;
515 s->reduced_width = (s->width + ((1 << width_bits) - 1)) >> width_bits;
517 /* color index values are delta-coded */
518 ct = img->frame->data[0] + 4;
519 for (x = 4; x < img->frame->width * 4; x++, ct++)
525 static HuffReader *get_huffman_group(WebPContext *s, ImageContext *img,
528 ImageContext *gimg = &s->image[IMAGE_ROLE_ENTROPY];
531 if (gimg->size_reduction > 0) {
532 int group_x = x >> gimg->size_reduction;
533 int group_y = y >> gimg->size_reduction;
534 int g0 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 1);
535 int g1 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 2);
536 group = g0 << 8 | g1;
539 return &img->huffman_groups[group * HUFFMAN_CODES_PER_META_CODE];
542 static av_always_inline void color_cache_put(ImageContext *img, uint32_t c)
544 uint32_t cache_idx = (0x1E35A7BD * c) >> (32 - img->color_cache_bits);
545 img->color_cache[cache_idx] = c;
548 static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role,
553 int i, j, ret, x, y, width;
555 img = &s->image[role];
559 img->frame = av_frame_alloc();
561 return AVERROR(ENOMEM);
564 img->frame->format = AV_PIX_FMT_ARGB;
565 img->frame->width = w;
566 img->frame->height = h;
568 if (role == IMAGE_ROLE_ARGB && !img->is_alpha_primary) {
569 ThreadFrame pt = { .f = img->frame };
570 ret = ff_thread_get_buffer(s->avctx, &pt, 0);
572 ret = av_frame_get_buffer(img->frame, 1);
576 if (get_bits1(&s->gb)) {
577 img->color_cache_bits = get_bits(&s->gb, 4);
578 if (img->color_cache_bits < 1 || img->color_cache_bits > 11) {
579 av_log(s->avctx, AV_LOG_ERROR, "invalid color cache bits: %d\n",
580 img->color_cache_bits);
581 return AVERROR_INVALIDDATA;
583 img->color_cache = av_mallocz_array(1 << img->color_cache_bits,
584 sizeof(*img->color_cache));
585 if (!img->color_cache)
586 return AVERROR(ENOMEM);
588 img->color_cache_bits = 0;
591 img->nb_huffman_groups = 1;
592 if (role == IMAGE_ROLE_ARGB && get_bits1(&s->gb)) {
593 ret = decode_entropy_image(s);
596 img->nb_huffman_groups = s->nb_huffman_groups;
598 img->huffman_groups = av_mallocz_array(img->nb_huffman_groups *
599 HUFFMAN_CODES_PER_META_CODE,
600 sizeof(*img->huffman_groups));
601 if (!img->huffman_groups)
602 return AVERROR(ENOMEM);
604 for (i = 0; i < img->nb_huffman_groups; i++) {
605 hg = &img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE];
606 for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) {
607 int alphabet_size = alphabet_sizes[j];
608 if (!j && img->color_cache_bits > 0)
609 alphabet_size += 1 << img->color_cache_bits;
611 if (get_bits1(&s->gb)) {
612 read_huffman_code_simple(s, &hg[j]);
614 ret = read_huffman_code_normal(s, &hg[j], alphabet_size);
621 width = img->frame->width;
622 if (role == IMAGE_ROLE_ARGB && s->reduced_width > 0)
623 width = s->reduced_width;
626 while (y < img->frame->height) {
629 hg = get_huffman_group(s, img, x, y);
630 v = huff_reader_get_symbol(&hg[HUFF_IDX_GREEN], &s->gb);
631 if (v < NUM_LITERAL_CODES) {
632 /* literal pixel values */
633 uint8_t *p = GET_PIXEL(img->frame, x, y);
635 p[1] = huff_reader_get_symbol(&hg[HUFF_IDX_RED], &s->gb);
636 p[3] = huff_reader_get_symbol(&hg[HUFF_IDX_BLUE], &s->gb);
637 p[0] = huff_reader_get_symbol(&hg[HUFF_IDX_ALPHA], &s->gb);
638 if (img->color_cache_bits)
639 color_cache_put(img, AV_RB32(p));
645 } else if (v < NUM_LITERAL_CODES + NUM_LENGTH_CODES) {
646 /* LZ77 backwards mapping */
647 int prefix_code, length, distance, ref_x, ref_y;
649 /* parse length and distance */
650 prefix_code = v - NUM_LITERAL_CODES;
651 if (prefix_code < 4) {
652 length = prefix_code + 1;
654 int extra_bits = (prefix_code - 2) >> 1;
655 int offset = 2 + (prefix_code & 1) << extra_bits;
656 length = offset + get_bits(&s->gb, extra_bits) + 1;
658 prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb);
659 if (prefix_code > 39U) {
660 av_log(s->avctx, AV_LOG_ERROR,
661 "distance prefix code too large: %d\n", prefix_code);
662 return AVERROR_INVALIDDATA;
664 if (prefix_code < 4) {
665 distance = prefix_code + 1;
667 int extra_bits = prefix_code - 2 >> 1;
668 int offset = 2 + (prefix_code & 1) << extra_bits;
669 distance = offset + get_bits(&s->gb, extra_bits) + 1;
672 /* find reference location */
673 if (distance <= NUM_SHORT_DISTANCES) {
674 int xi = lz77_distance_offsets[distance - 1][0];
675 int yi = lz77_distance_offsets[distance - 1][1];
676 distance = FFMAX(1, xi + yi * width);
678 distance -= NUM_SHORT_DISTANCES;
689 while (distance >= width) {
694 ref_x = width - distance;
697 ref_x = FFMAX(0, ref_x);
698 ref_y = FFMAX(0, ref_y);
701 * source and dest regions can overlap and wrap lines, so just
703 for (i = 0; i < length; i++) {
704 uint8_t *p_ref = GET_PIXEL(img->frame, ref_x, ref_y);
705 uint8_t *p = GET_PIXEL(img->frame, x, y);
708 if (img->color_cache_bits)
709 color_cache_put(img, AV_RB32(p));
716 if (ref_x == width) {
720 if (y == img->frame->height || ref_y == img->frame->height)
724 /* read from color cache */
725 uint8_t *p = GET_PIXEL(img->frame, x, y);
726 int cache_idx = v - (NUM_LITERAL_CODES + NUM_LENGTH_CODES);
728 if (!img->color_cache_bits) {
729 av_log(s->avctx, AV_LOG_ERROR, "color cache not found\n");
730 return AVERROR_INVALIDDATA;
732 if (cache_idx >= 1 << img->color_cache_bits) {
733 av_log(s->avctx, AV_LOG_ERROR,
734 "color cache index out-of-bounds\n");
735 return AVERROR_INVALIDDATA;
737 AV_WB32(p, img->color_cache[cache_idx]);
749 /* PRED_MODE_BLACK */
750 static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
751 const uint8_t *p_t, const uint8_t *p_tr)
753 AV_WB32(p, 0xFF000000);
757 static void inv_predict_1(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
758 const uint8_t *p_t, const uint8_t *p_tr)
764 static void inv_predict_2(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
765 const uint8_t *p_t, const uint8_t *p_tr)
771 static void inv_predict_3(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
772 const uint8_t *p_t, const uint8_t *p_tr)
778 static void inv_predict_4(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
779 const uint8_t *p_t, const uint8_t *p_tr)
784 /* PRED_MODE_AVG_T_AVG_L_TR */
785 static void inv_predict_5(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
786 const uint8_t *p_t, const uint8_t *p_tr)
788 p[0] = p_t[0] + (p_l[0] + p_tr[0] >> 1) >> 1;
789 p[1] = p_t[1] + (p_l[1] + p_tr[1] >> 1) >> 1;
790 p[2] = p_t[2] + (p_l[2] + p_tr[2] >> 1) >> 1;
791 p[3] = p_t[3] + (p_l[3] + p_tr[3] >> 1) >> 1;
794 /* PRED_MODE_AVG_L_TL */
795 static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
796 const uint8_t *p_t, const uint8_t *p_tr)
798 p[0] = p_l[0] + p_tl[0] >> 1;
799 p[1] = p_l[1] + p_tl[1] >> 1;
800 p[2] = p_l[2] + p_tl[2] >> 1;
801 p[3] = p_l[3] + p_tl[3] >> 1;
804 /* PRED_MODE_AVG_L_T */
805 static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
806 const uint8_t *p_t, const uint8_t *p_tr)
808 p[0] = p_l[0] + p_t[0] >> 1;
809 p[1] = p_l[1] + p_t[1] >> 1;
810 p[2] = p_l[2] + p_t[2] >> 1;
811 p[3] = p_l[3] + p_t[3] >> 1;
814 /* PRED_MODE_AVG_TL_T */
815 static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
816 const uint8_t *p_t, const uint8_t *p_tr)
818 p[0] = p_tl[0] + p_t[0] >> 1;
819 p[1] = p_tl[1] + p_t[1] >> 1;
820 p[2] = p_tl[2] + p_t[2] >> 1;
821 p[3] = p_tl[3] + p_t[3] >> 1;
824 /* PRED_MODE_AVG_T_TR */
825 static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
826 const uint8_t *p_t, const uint8_t *p_tr)
828 p[0] = p_t[0] + p_tr[0] >> 1;
829 p[1] = p_t[1] + p_tr[1] >> 1;
830 p[2] = p_t[2] + p_tr[2] >> 1;
831 p[3] = p_t[3] + p_tr[3] >> 1;
834 /* PRED_MODE_AVG_AVG_L_TL_AVG_T_TR */
835 static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
836 const uint8_t *p_t, const uint8_t *p_tr)
838 p[0] = (p_l[0] + p_tl[0] >> 1) + (p_t[0] + p_tr[0] >> 1) >> 1;
839 p[1] = (p_l[1] + p_tl[1] >> 1) + (p_t[1] + p_tr[1] >> 1) >> 1;
840 p[2] = (p_l[2] + p_tl[2] >> 1) + (p_t[2] + p_tr[2] >> 1) >> 1;
841 p[3] = (p_l[3] + p_tl[3] >> 1) + (p_t[3] + p_tr[3] >> 1) >> 1;
844 /* PRED_MODE_SELECT */
845 static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
846 const uint8_t *p_t, const uint8_t *p_tr)
848 int diff = (FFABS(p_l[0] - p_tl[0]) - FFABS(p_t[0] - p_tl[0])) +
849 (FFABS(p_l[1] - p_tl[1]) - FFABS(p_t[1] - p_tl[1])) +
850 (FFABS(p_l[2] - p_tl[2]) - FFABS(p_t[2] - p_tl[2])) +
851 (FFABS(p_l[3] - p_tl[3]) - FFABS(p_t[3] - p_tl[3]));
858 /* PRED_MODE_ADD_SUBTRACT_FULL */
859 static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
860 const uint8_t *p_t, const uint8_t *p_tr)
862 p[0] = av_clip_uint8(p_l[0] + p_t[0] - p_tl[0]);
863 p[1] = av_clip_uint8(p_l[1] + p_t[1] - p_tl[1]);
864 p[2] = av_clip_uint8(p_l[2] + p_t[2] - p_tl[2]);
865 p[3] = av_clip_uint8(p_l[3] + p_t[3] - p_tl[3]);
868 static av_always_inline uint8_t clamp_add_subtract_half(int a, int b, int c)
871 return av_clip_uint8(d + (d - c) / 2);
874 /* PRED_MODE_ADD_SUBTRACT_HALF */
875 static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl,
876 const uint8_t *p_t, const uint8_t *p_tr)
878 p[0] = clamp_add_subtract_half(p_l[0], p_t[0], p_tl[0]);
879 p[1] = clamp_add_subtract_half(p_l[1], p_t[1], p_tl[1]);
880 p[2] = clamp_add_subtract_half(p_l[2], p_t[2], p_tl[2]);
881 p[3] = clamp_add_subtract_half(p_l[3], p_t[3], p_tl[3]);
884 typedef void (*inv_predict_func)(uint8_t *p, const uint8_t *p_l,
885 const uint8_t *p_tl, const uint8_t *p_t,
886 const uint8_t *p_tr);
888 static const inv_predict_func inverse_predict[14] = {
889 inv_predict_0, inv_predict_1, inv_predict_2, inv_predict_3,
890 inv_predict_4, inv_predict_5, inv_predict_6, inv_predict_7,
891 inv_predict_8, inv_predict_9, inv_predict_10, inv_predict_11,
892 inv_predict_12, inv_predict_13,
895 static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y)
897 uint8_t *dec, *p_l, *p_tl, *p_t, *p_tr;
900 dec = GET_PIXEL(frame, x, y);
901 p_l = GET_PIXEL(frame, x - 1, y);
902 p_tl = GET_PIXEL(frame, x - 1, y - 1);
903 p_t = GET_PIXEL(frame, x, y - 1);
904 if (x == frame->width - 1)
905 p_tr = GET_PIXEL(frame, 0, y);
907 p_tr = GET_PIXEL(frame, x + 1, y - 1);
909 inverse_predict[m](p, p_l, p_tl, p_t, p_tr);
917 static int apply_predictor_transform(WebPContext *s)
919 ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
920 ImageContext *pimg = &s->image[IMAGE_ROLE_PREDICTOR];
923 for (y = 0; y < img->frame->height; y++) {
924 for (x = 0; x < img->frame->width; x++) {
925 int tx = x >> pimg->size_reduction;
926 int ty = y >> pimg->size_reduction;
927 enum PredictionMode m = GET_PIXEL_COMP(pimg->frame, tx, ty, 2);
938 av_log(s->avctx, AV_LOG_ERROR,
939 "invalid predictor mode: %d\n", m);
940 return AVERROR_INVALIDDATA;
942 inverse_prediction(img->frame, m, x, y);
948 static av_always_inline uint8_t color_transform_delta(uint8_t color_pred,
951 return (int)ff_u8_to_s8(color_pred) * ff_u8_to_s8(color) >> 5;
954 static int apply_color_transform(WebPContext *s)
956 ImageContext *img, *cimg;
960 img = &s->image[IMAGE_ROLE_ARGB];
961 cimg = &s->image[IMAGE_ROLE_COLOR_TRANSFORM];
963 for (y = 0; y < img->frame->height; y++) {
964 for (x = 0; x < img->frame->width; x++) {
965 cx = x >> cimg->size_reduction;
966 cy = y >> cimg->size_reduction;
967 cp = GET_PIXEL(cimg->frame, cx, cy);
968 p = GET_PIXEL(img->frame, x, y);
970 p[1] += color_transform_delta(cp[3], p[2]);
971 p[3] += color_transform_delta(cp[2], p[2]) +
972 color_transform_delta(cp[1], p[1]);
978 static int apply_subtract_green_transform(WebPContext *s)
981 ImageContext *img = &s->image[IMAGE_ROLE_ARGB];
983 for (y = 0; y < img->frame->height; y++) {
984 for (x = 0; x < img->frame->width; x++) {
985 uint8_t *p = GET_PIXEL(img->frame, x, y);
993 static int apply_color_indexing_transform(WebPContext *s)
1000 img = &s->image[IMAGE_ROLE_ARGB];
1001 pal = &s->image[IMAGE_ROLE_COLOR_INDEXING];
1003 if (pal->size_reduction > 0) {
1006 int pixel_bits = 8 >> pal->size_reduction;
1008 line = av_malloc(img->frame->linesize[0] + AV_INPUT_BUFFER_PADDING_SIZE);
1010 return AVERROR(ENOMEM);
1012 for (y = 0; y < img->frame->height; y++) {
1013 p = GET_PIXEL(img->frame, 0, y);
1014 memcpy(line, p, img->frame->linesize[0]);
1015 init_get_bits(&gb_g, line, img->frame->linesize[0] * 8);
1016 skip_bits(&gb_g, 16);
1018 for (x = 0; x < img->frame->width; x++) {
1019 p = GET_PIXEL(img->frame, x, y);
1020 p[2] = get_bits(&gb_g, pixel_bits);
1022 if (i == 1 << pal->size_reduction) {
1023 skip_bits(&gb_g, 24);
1031 // switch to local palette if it's worth initializing it
1032 if (img->frame->height * img->frame->width > 300) {
1033 uint8_t palette[256 * 4];
1034 const int size = pal->frame->width * 4;
1035 av_assert0(size <= 1024U);
1036 memcpy(palette, GET_PIXEL(pal->frame, 0, 0), size); // copy palette
1037 // set extra entries to transparent black
1038 memset(palette + size, 0, 256 * 4 - size);
1039 for (y = 0; y < img->frame->height; y++) {
1040 for (x = 0; x < img->frame->width; x++) {
1041 p = GET_PIXEL(img->frame, x, y);
1043 AV_COPY32(p, &palette[i * 4]);
1047 for (y = 0; y < img->frame->height; y++) {
1048 for (x = 0; x < img->frame->width; x++) {
1049 p = GET_PIXEL(img->frame, x, y);
1051 if (i >= pal->frame->width) {
1052 AV_WB32(p, 0x00000000);
1054 const uint8_t *pi = GET_PIXEL(pal->frame, i, 0);
1064 static void update_canvas_size(AVCodecContext *avctx, int w, int h)
1066 WebPContext *s = avctx->priv_data;
1067 if (s->width && s->width != w) {
1068 av_log(avctx, AV_LOG_WARNING, "Width mismatch. %d != %d\n",
1072 if (s->height && s->height != h) {
1073 av_log(avctx, AV_LOG_WARNING, "Height mismatch. %d != %d\n",
1079 static int vp8_lossless_decode_frame(AVCodecContext *avctx, AVFrame *p,
1080 int *got_frame, uint8_t *data_start,
1081 unsigned int data_size, int is_alpha_chunk)
1083 WebPContext *s = avctx->priv_data;
1084 int w, h, ret, i, used;
1086 if (!is_alpha_chunk) {
1088 avctx->pix_fmt = AV_PIX_FMT_ARGB;
1091 ret = init_get_bits8(&s->gb, data_start, data_size);
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;
1101 w = get_bits(&s->gb, 14) + 1;
1102 h = get_bits(&s->gb, 14) + 1;
1104 update_canvas_size(avctx, w, h);
1106 ret = ff_set_dimensions(avctx, s->width, s->height);
1110 s->has_alpha = get_bits1(&s->gb);
1112 if (get_bits(&s->gb, 3) != 0x0) {
1113 av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless version\n");
1114 return AVERROR_INVALIDDATA;
1117 if (!s->width || !s->height)
1123 /* parse transformations */
1124 s->nb_transforms = 0;
1125 s->reduced_width = 0;
1127 while (get_bits1(&s->gb)) {
1128 enum TransformType transform = get_bits(&s->gb, 2);
1129 if (used & (1 << transform)) {
1130 av_log(avctx, AV_LOG_ERROR, "Transform %d used more than once\n",
1132 ret = AVERROR_INVALIDDATA;
1133 goto free_and_return;
1135 used |= (1 << transform);
1136 s->transforms[s->nb_transforms++] = transform;
1137 switch (transform) {
1138 case PREDICTOR_TRANSFORM:
1139 ret = parse_transform_predictor(s);
1141 case COLOR_TRANSFORM:
1142 ret = parse_transform_color(s);
1144 case COLOR_INDEXING_TRANSFORM:
1145 ret = parse_transform_color_indexing(s);
1149 goto free_and_return;
1152 /* decode primary image */
1153 s->image[IMAGE_ROLE_ARGB].frame = p;
1155 s->image[IMAGE_ROLE_ARGB].is_alpha_primary = 1;
1156 ret = decode_entropy_coded_image(s, IMAGE_ROLE_ARGB, w, h);
1158 goto free_and_return;
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);
1166 case COLOR_TRANSFORM:
1167 ret = apply_color_transform(s);
1169 case SUBTRACT_GREEN:
1170 ret = apply_subtract_green_transform(s);
1172 case COLOR_INDEXING_TRANSFORM:
1173 ret = apply_color_indexing_transform(s);
1177 goto free_and_return;
1181 p->pict_type = AV_PICTURE_TYPE_I;
1186 for (i = 0; i < IMAGE_ROLE_NB; i++)
1187 image_ctx_free(&s->image[i]);
1192 static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
1197 ls = frame->linesize[3];
1199 /* filter first row using horizontal filter */
1200 dec = frame->data[3] + 1;
1201 for (x = 1; x < frame->width; x++, dec++)
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);
1209 /* filter the rest using the specified filter */
1211 case ALPHA_FILTER_HORIZONTAL:
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++)
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);
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));
1235 static int vp8_lossy_decode_alpha(AVCodecContext *avctx, AVFrame *p,
1236 uint8_t *data_start,
1237 unsigned int data_size)
1239 WebPContext *s = avctx->priv_data;
1242 if (s->alpha_compression == ALPHA_COMPRESSION_NONE) {
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,
1249 } else if (s->alpha_compression == ALPHA_COMPRESSION_VP8L) {
1251 int alpha_got_frame = 0;
1253 s->alpha_frame = av_frame_alloc();
1254 if (!s->alpha_frame)
1255 return AVERROR(ENOMEM);
1257 ret = vp8_lossless_decode_frame(avctx, s->alpha_frame, &alpha_got_frame,
1258 data_start, data_size, 1);
1260 av_frame_free(&s->alpha_frame);
1263 if (!alpha_got_frame) {
1264 av_frame_free(&s->alpha_frame);
1265 return AVERROR_INVALIDDATA;
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++) {
1278 av_frame_free(&s->alpha_frame);
1281 /* apply alpha filtering */
1282 if (s->alpha_filter)
1283 alpha_inverse_prediction(p, s->alpha_filter);
1288 static int vp8_lossy_decode_frame(AVCodecContext *avctx, AVFrame *p,
1289 int *got_frame, uint8_t *data_start,
1290 unsigned int data_size)
1292 WebPContext *s = avctx->priv_data;
1296 if (!s->initialized) {
1297 ff_vp8_decode_init(avctx);
1299 s->v.actually_webp = 1;
1301 avctx->pix_fmt = s->has_alpha ? AV_PIX_FMT_YUVA420P : AV_PIX_FMT_YUV420P;
1304 if (data_size > INT_MAX) {
1305 av_log(avctx, AV_LOG_ERROR, "unsupported chunk size\n");
1306 return AVERROR_PATCHWELCOME;
1309 av_init_packet(&pkt);
1310 pkt.data = data_start;
1311 pkt.size = data_size;
1313 ret = ff_vp8_decode_frame(avctx, p, got_frame, &pkt);
1318 return AVERROR_INVALIDDATA;
1320 update_canvas_size(avctx, avctx->width, avctx->height);
1323 ret = vp8_lossy_decode_alpha(avctx, p, s->alpha_data,
1324 s->alpha_data_size);
1331 static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
1334 AVFrame * const p = data;
1335 WebPContext *s = avctx->priv_data;
1338 uint32_t chunk_type, chunk_size;
1348 bytestream2_init(&gb, avpkt->data, avpkt->size);
1350 if (bytestream2_get_bytes_left(&gb) < 12)
1351 return AVERROR_INVALIDDATA;
1353 if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
1354 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
1355 return AVERROR_INVALIDDATA;
1358 chunk_size = bytestream2_get_le32(&gb);
1359 if (bytestream2_get_bytes_left(&gb) < chunk_size)
1360 return AVERROR_INVALIDDATA;
1362 if (bytestream2_get_le32(&gb) != MKTAG('W', 'E', 'B', 'P')) {
1363 av_log(avctx, AV_LOG_ERROR, "missing WEBP tag\n");
1364 return AVERROR_INVALIDDATA;
1367 while (bytestream2_get_bytes_left(&gb) > 8) {
1368 char chunk_str[5] = { 0 };
1370 chunk_type = bytestream2_get_le32(&gb);
1371 chunk_size = bytestream2_get_le32(&gb);
1372 if (chunk_size == UINT32_MAX)
1373 return AVERROR_INVALIDDATA;
1374 chunk_size += chunk_size & 1;
1376 if (bytestream2_get_bytes_left(&gb) < chunk_size) {
1377 /* we seem to be running out of data, but it could also be that the
1378 bitstream has trailing junk leading to bogus chunk_size. */
1382 switch (chunk_type) {
1383 case MKTAG('V', 'P', '8', ' '):
1385 ret = vp8_lossy_decode_frame(avctx, p, got_frame,
1386 avpkt->data + bytestream2_tell(&gb),
1391 bytestream2_skip(&gb, chunk_size);
1393 case MKTAG('V', 'P', '8', 'L'):
1395 ret = vp8_lossless_decode_frame(avctx, p, got_frame,
1396 avpkt->data + bytestream2_tell(&gb),
1400 avctx->properties |= FF_CODEC_PROPERTY_LOSSLESS;
1402 bytestream2_skip(&gb, chunk_size);
1404 case MKTAG('V', 'P', '8', 'X'):
1405 if (s->width || s->height || *got_frame) {
1406 av_log(avctx, AV_LOG_ERROR, "Canvas dimensions are already set\n");
1407 return AVERROR_INVALIDDATA;
1409 vp8x_flags = bytestream2_get_byte(&gb);
1410 bytestream2_skip(&gb, 3);
1411 s->width = bytestream2_get_le24(&gb) + 1;
1412 s->height = bytestream2_get_le24(&gb) + 1;
1413 ret = av_image_check_size(s->width, s->height, 0, avctx);
1417 case MKTAG('A', 'L', 'P', 'H'): {
1418 int alpha_header, filter_m, compression;
1420 if (!(vp8x_flags & VP8X_FLAG_ALPHA)) {
1421 av_log(avctx, AV_LOG_WARNING,
1422 "ALPHA chunk present, but alpha bit not set in the "
1425 if (chunk_size == 0) {
1426 av_log(avctx, AV_LOG_ERROR, "invalid ALPHA chunk size\n");
1427 return AVERROR_INVALIDDATA;
1429 alpha_header = bytestream2_get_byte(&gb);
1430 s->alpha_data = avpkt->data + bytestream2_tell(&gb);
1431 s->alpha_data_size = chunk_size - 1;
1432 bytestream2_skip(&gb, s->alpha_data_size);
1434 filter_m = (alpha_header >> 2) & 0x03;
1435 compression = alpha_header & 0x03;
1437 if (compression > ALPHA_COMPRESSION_VP8L) {
1438 av_log(avctx, AV_LOG_VERBOSE,
1439 "skipping unsupported ALPHA chunk\n");
1442 s->alpha_compression = compression;
1443 s->alpha_filter = filter_m;
1448 case MKTAG('E', 'X', 'I', 'F'): {
1449 int le, ifd_offset, exif_offset = bytestream2_tell(&gb);
1450 AVDictionary *exif_metadata = NULL;
1451 GetByteContext exif_gb;
1454 av_log(avctx, AV_LOG_VERBOSE, "Ignoring extra EXIF chunk\n");
1457 if (!(vp8x_flags & VP8X_FLAG_EXIF_METADATA))
1458 av_log(avctx, AV_LOG_WARNING,
1459 "EXIF chunk present, but Exif bit not set in the "
1463 bytestream2_init(&exif_gb, avpkt->data + exif_offset,
1464 avpkt->size - exif_offset);
1465 if (ff_tdecode_header(&exif_gb, &le, &ifd_offset) < 0) {
1466 av_log(avctx, AV_LOG_ERROR, "invalid TIFF header "
1471 bytestream2_seek(&exif_gb, ifd_offset, SEEK_SET);
1472 if (ff_exif_decode_ifd(avctx, &exif_gb, le, 0, &exif_metadata) < 0) {
1473 av_log(avctx, AV_LOG_ERROR, "error decoding Exif data\n");
1477 av_dict_copy(&((AVFrame *) data)->metadata, exif_metadata, 0);
1480 av_dict_free(&exif_metadata);
1481 bytestream2_skip(&gb, chunk_size);
1484 case MKTAG('I', 'C', 'C', 'P'): {
1485 AVFrameSideData *sd;
1488 av_log(avctx, AV_LOG_VERBOSE, "Ignoring extra ICCP chunk\n");
1489 bytestream2_skip(&gb, chunk_size);
1492 if (!(vp8x_flags & VP8X_FLAG_ICC))
1493 av_log(avctx, AV_LOG_WARNING,
1494 "ICCP chunk present, but ICC Profile bit not set in the "
1498 sd = av_frame_new_side_data(p, AV_FRAME_DATA_ICC_PROFILE, chunk_size);
1500 return AVERROR(ENOMEM);
1502 bytestream2_get_buffer(&gb, sd->data, chunk_size);
1505 case MKTAG('A', 'N', 'I', 'M'):
1506 case MKTAG('A', 'N', 'M', 'F'):
1507 case MKTAG('X', 'M', 'P', ' '):
1508 AV_WL32(chunk_str, chunk_type);
1509 av_log(avctx, AV_LOG_WARNING, "skipping unsupported chunk: %s\n",
1511 bytestream2_skip(&gb, chunk_size);
1514 AV_WL32(chunk_str, chunk_type);
1515 av_log(avctx, AV_LOG_VERBOSE, "skipping unknown chunk: %s\n",
1517 bytestream2_skip(&gb, chunk_size);
1523 av_log(avctx, AV_LOG_ERROR, "image data not found\n");
1524 return AVERROR_INVALIDDATA;
1530 static av_cold int webp_decode_close(AVCodecContext *avctx)
1532 WebPContext *s = avctx->priv_data;
1535 return ff_vp8_decode_free(avctx);
1540 AVCodec ff_webp_decoder = {
1542 .long_name = NULL_IF_CONFIG_SMALL("WebP image"),
1543 .type = AVMEDIA_TYPE_VIDEO,
1544 .id = AV_CODEC_ID_WEBP,
1545 .priv_data_size = sizeof(WebPContext),
1546 .decode = webp_decode_frame,
1547 .close = webp_decode_close,
1548 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,