| /* |
| * WebP (.webp) image decoder |
| * Copyright (c) 2013 Aneesh Dogra <aneesh@sugarlabs.org> |
| * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * WebP image decoder |
| * |
| * @author Aneesh Dogra <aneesh@sugarlabs.org> |
| * Container and Lossy decoding |
| * |
| * @author Justin Ruggles <justin.ruggles@gmail.com> |
| * Lossless decoder |
| * Compressed alpha for lossy |
| * |
| * @author James Almer <jamrial@gmail.com> |
| * Exif metadata |
| * |
| * Unimplemented: |
| * - Animation |
| * - ICC profile |
| * - XMP metadata |
| */ |
| |
| #define BITSTREAM_READER_LE |
| #include "libavutil/imgutils.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "exif.h" |
| #include "internal.h" |
| #include "get_bits.h" |
| #include "thread.h" |
| #include "vp8.h" |
| |
| #define VP8X_FLAG_ANIMATION 0x02 |
| #define VP8X_FLAG_XMP_METADATA 0x04 |
| #define VP8X_FLAG_EXIF_METADATA 0x08 |
| #define VP8X_FLAG_ALPHA 0x10 |
| #define VP8X_FLAG_ICC 0x20 |
| |
| #define MAX_PALETTE_SIZE 256 |
| #define MAX_CACHE_BITS 11 |
| #define NUM_CODE_LENGTH_CODES 19 |
| #define HUFFMAN_CODES_PER_META_CODE 5 |
| #define NUM_LITERAL_CODES 256 |
| #define NUM_LENGTH_CODES 24 |
| #define NUM_DISTANCE_CODES 40 |
| #define NUM_SHORT_DISTANCES 120 |
| #define MAX_HUFFMAN_CODE_LENGTH 15 |
| |
| static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE] = { |
| NUM_LITERAL_CODES + NUM_LENGTH_CODES, |
| NUM_LITERAL_CODES, NUM_LITERAL_CODES, NUM_LITERAL_CODES, |
| NUM_DISTANCE_CODES |
| }; |
| |
| static const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES] = { |
| 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 |
| }; |
| |
| static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2] = { |
| { 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 }, |
| { 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 }, |
| { 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 }, |
| { 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 }, |
| { 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 }, |
| { 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 }, |
| { 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 }, |
| { 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 }, |
| { 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 }, |
| { 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 }, |
| { 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 }, |
| { 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 }, |
| { 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 }, |
| { -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 }, |
| { -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 } |
| }; |
| |
| enum AlphaCompression { |
| ALPHA_COMPRESSION_NONE, |
| ALPHA_COMPRESSION_VP8L, |
| }; |
| |
| enum AlphaFilter { |
| ALPHA_FILTER_NONE, |
| ALPHA_FILTER_HORIZONTAL, |
| ALPHA_FILTER_VERTICAL, |
| ALPHA_FILTER_GRADIENT, |
| }; |
| |
| enum TransformType { |
| PREDICTOR_TRANSFORM = 0, |
| COLOR_TRANSFORM = 1, |
| SUBTRACT_GREEN = 2, |
| COLOR_INDEXING_TRANSFORM = 3, |
| }; |
| |
| enum PredictionMode { |
| PRED_MODE_BLACK, |
| PRED_MODE_L, |
| PRED_MODE_T, |
| PRED_MODE_TR, |
| PRED_MODE_TL, |
| PRED_MODE_AVG_T_AVG_L_TR, |
| PRED_MODE_AVG_L_TL, |
| PRED_MODE_AVG_L_T, |
| PRED_MODE_AVG_TL_T, |
| PRED_MODE_AVG_T_TR, |
| PRED_MODE_AVG_AVG_L_TL_AVG_T_TR, |
| PRED_MODE_SELECT, |
| PRED_MODE_ADD_SUBTRACT_FULL, |
| PRED_MODE_ADD_SUBTRACT_HALF, |
| }; |
| |
| enum HuffmanIndex { |
| HUFF_IDX_GREEN = 0, |
| HUFF_IDX_RED = 1, |
| HUFF_IDX_BLUE = 2, |
| HUFF_IDX_ALPHA = 3, |
| HUFF_IDX_DIST = 4 |
| }; |
| |
| /* The structure of WebP lossless is an optional series of transformation data, |
| * followed by the primary image. The primary image also optionally contains |
| * an entropy group mapping if there are multiple entropy groups. There is a |
| * basic image type called an "entropy coded image" that is used for all of |
| * these. The type of each entropy coded image is referred to by the |
| * specification as its role. */ |
| enum ImageRole { |
| /* Primary Image: Stores the actual pixels of the image. */ |
| IMAGE_ROLE_ARGB, |
| |
| /* Entropy Image: Defines which Huffman group to use for different areas of |
| * the primary image. */ |
| IMAGE_ROLE_ENTROPY, |
| |
| /* Predictors: Defines which predictor type to use for different areas of |
| * the primary image. */ |
| IMAGE_ROLE_PREDICTOR, |
| |
| /* Color Transform Data: Defines the color transformation for different |
| * areas of the primary image. */ |
| IMAGE_ROLE_COLOR_TRANSFORM, |
| |
| /* Color Index: Stored as an image of height == 1. */ |
| IMAGE_ROLE_COLOR_INDEXING, |
| |
| IMAGE_ROLE_NB, |
| }; |
| |
| typedef struct HuffReader { |
| VLC vlc; /* Huffman decoder context */ |
| int simple; /* whether to use simple mode */ |
| int nb_symbols; /* number of coded symbols */ |
| uint16_t simple_symbols[2]; /* symbols for simple mode */ |
| } HuffReader; |
| |
| typedef struct ImageContext { |
| enum ImageRole role; /* role of this image */ |
| AVFrame *frame; /* AVFrame for data */ |
| int color_cache_bits; /* color cache size, log2 */ |
| uint32_t *color_cache; /* color cache data */ |
| int nb_huffman_groups; /* number of huffman groups */ |
| HuffReader *huffman_groups; /* reader for each huffman group */ |
| int size_reduction; /* relative size compared to primary image, log2 */ |
| int is_alpha_primary; |
| } ImageContext; |
| |
| typedef struct WebPContext { |
| VP8Context v; /* VP8 Context used for lossy decoding */ |
| GetBitContext gb; /* bitstream reader for main image chunk */ |
| AVFrame *alpha_frame; /* AVFrame for alpha data decompressed from VP8L */ |
| AVCodecContext *avctx; /* parent AVCodecContext */ |
| int initialized; /* set once the VP8 context is initialized */ |
| int has_alpha; /* has a separate alpha chunk */ |
| enum AlphaCompression alpha_compression; /* compression type for alpha chunk */ |
| enum AlphaFilter alpha_filter; /* filtering method for alpha chunk */ |
| uint8_t *alpha_data; /* alpha chunk data */ |
| int alpha_data_size; /* alpha chunk data size */ |
| int has_exif; /* set after an EXIF chunk has been processed */ |
| AVDictionary *exif_metadata; /* EXIF chunk data */ |
| int width; /* image width */ |
| int height; /* image height */ |
| int lossless; /* indicates lossless or lossy */ |
| |
| int nb_transforms; /* number of transforms */ |
| enum TransformType transforms[4]; /* transformations used in the image, in order */ |
| int reduced_width; /* reduced width for index image, if applicable */ |
| int nb_huffman_groups; /* number of huffman groups in the primary image */ |
| ImageContext image[IMAGE_ROLE_NB]; /* image context for each role */ |
| } WebPContext; |
| |
| #define GET_PIXEL(frame, x, y) \ |
| ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x)) |
| |
| #define GET_PIXEL_COMP(frame, x, y, c) \ |
| (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c)) |
| |
| static void image_ctx_free(ImageContext *img) |
| { |
| int i, j; |
| |
| av_free(img->color_cache); |
| if (img->role != IMAGE_ROLE_ARGB && !img->is_alpha_primary) |
| av_frame_free(&img->frame); |
| if (img->huffman_groups) { |
| for (i = 0; i < img->nb_huffman_groups; i++) { |
| for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) |
| ff_free_vlc(&img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE + j].vlc); |
| } |
| av_free(img->huffman_groups); |
| } |
| memset(img, 0, sizeof(*img)); |
| } |
| |
| |
| /* Differs from get_vlc2() in the following ways: |
| * - codes are bit-reversed |
| * - assumes 8-bit table to make reversal simpler |
| * - assumes max depth of 2 since the max code length for WebP is 15 |
| */ |
| static av_always_inline int webp_get_vlc(GetBitContext *gb, VLC_TYPE (*table)[2]) |
| { |
| int n, nb_bits; |
| unsigned int index; |
| int code; |
| |
| OPEN_READER(re, gb); |
| UPDATE_CACHE(re, gb); |
| |
| index = SHOW_UBITS(re, gb, 8); |
| index = ff_reverse[index]; |
| code = table[index][0]; |
| n = table[index][1]; |
| |
| if (n < 0) { |
| LAST_SKIP_BITS(re, gb, 8); |
| UPDATE_CACHE(re, gb); |
| |
| nb_bits = -n; |
| |
| index = SHOW_UBITS(re, gb, nb_bits); |
| index = (ff_reverse[index] >> (8 - nb_bits)) + code; |
| code = table[index][0]; |
| n = table[index][1]; |
| } |
| SKIP_BITS(re, gb, n); |
| |
| CLOSE_READER(re, gb); |
| |
| return code; |
| } |
| |
| static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb) |
| { |
| if (r->simple) { |
| if (r->nb_symbols == 1) |
| return r->simple_symbols[0]; |
| else |
| return r->simple_symbols[get_bits1(gb)]; |
| } else |
| return webp_get_vlc(gb, r->vlc.table); |
| } |
| |
| static int huff_reader_build_canonical(HuffReader *r, int *code_lengths, |
| int alphabet_size) |
| { |
| int len = 0, sym, code = 0, ret; |
| int max_code_length = 0; |
| uint16_t *codes; |
| |
| /* special-case 1 symbol since the vlc reader cannot handle it */ |
| for (sym = 0; sym < alphabet_size; sym++) { |
| if (code_lengths[sym] > 0) { |
| len++; |
| code = sym; |
| if (len > 1) |
| break; |
| } |
| } |
| if (len == 1) { |
| r->nb_symbols = 1; |
| r->simple_symbols[0] = code; |
| r->simple = 1; |
| return 0; |
| } |
| |
| for (sym = 0; sym < alphabet_size; sym++) |
| max_code_length = FFMAX(max_code_length, code_lengths[sym]); |
| |
| if (max_code_length == 0 || max_code_length > MAX_HUFFMAN_CODE_LENGTH) |
| return AVERROR(EINVAL); |
| |
| codes = av_malloc_array(alphabet_size, sizeof(*codes)); |
| if (!codes) |
| return AVERROR(ENOMEM); |
| |
| code = 0; |
| r->nb_symbols = 0; |
| for (len = 1; len <= max_code_length; len++) { |
| for (sym = 0; sym < alphabet_size; sym++) { |
| if (code_lengths[sym] != len) |
| continue; |
| codes[sym] = code++; |
| r->nb_symbols++; |
| } |
| code <<= 1; |
| } |
| if (!r->nb_symbols) { |
| av_free(codes); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| ret = init_vlc(&r->vlc, 8, alphabet_size, |
| code_lengths, sizeof(*code_lengths), sizeof(*code_lengths), |
| codes, sizeof(*codes), sizeof(*codes), 0); |
| if (ret < 0) { |
| av_free(codes); |
| return ret; |
| } |
| r->simple = 0; |
| |
| av_free(codes); |
| return 0; |
| } |
| |
| static void read_huffman_code_simple(WebPContext *s, HuffReader *hc) |
| { |
| hc->nb_symbols = get_bits1(&s->gb) + 1; |
| |
| if (get_bits1(&s->gb)) |
| hc->simple_symbols[0] = get_bits(&s->gb, 8); |
| else |
| hc->simple_symbols[0] = get_bits1(&s->gb); |
| |
| if (hc->nb_symbols == 2) |
| hc->simple_symbols[1] = get_bits(&s->gb, 8); |
| |
| hc->simple = 1; |
| } |
| |
| static int read_huffman_code_normal(WebPContext *s, HuffReader *hc, |
| int alphabet_size) |
| { |
| HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } }; |
| int *code_lengths = NULL; |
| int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 }; |
| int i, symbol, max_symbol, prev_code_len, ret; |
| int num_codes = 4 + get_bits(&s->gb, 4); |
| |
| if (num_codes > NUM_CODE_LENGTH_CODES) |
| return AVERROR_INVALIDDATA; |
| |
| for (i = 0; i < num_codes; i++) |
| code_length_code_lengths[code_length_code_order[i]] = get_bits(&s->gb, 3); |
| |
| ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths, |
| NUM_CODE_LENGTH_CODES); |
| if (ret < 0) |
| goto finish; |
| |
| code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths)); |
| if (!code_lengths) { |
| ret = AVERROR(ENOMEM); |
| goto finish; |
| } |
| |
| if (get_bits1(&s->gb)) { |
| int bits = 2 + 2 * get_bits(&s->gb, 3); |
| max_symbol = 2 + get_bits(&s->gb, bits); |
| if (max_symbol > alphabet_size) { |
| av_log(s->avctx, AV_LOG_ERROR, "max symbol %d > alphabet size %d\n", |
| max_symbol, alphabet_size); |
| ret = AVERROR_INVALIDDATA; |
| goto finish; |
| } |
| } else { |
| max_symbol = alphabet_size; |
| } |
| |
| prev_code_len = 8; |
| symbol = 0; |
| while (symbol < alphabet_size) { |
| int code_len; |
| |
| if (!max_symbol--) |
| break; |
| code_len = huff_reader_get_symbol(&code_len_hc, &s->gb); |
| if (code_len < 16) { |
| /* Code length code [0..15] indicates literal code lengths. */ |
| code_lengths[symbol++] = code_len; |
| if (code_len) |
| prev_code_len = code_len; |
| } else { |
| int repeat = 0, length = 0; |
| switch (code_len) { |
| case 16: |
| /* Code 16 repeats the previous non-zero value [3..6] times, |
| * i.e., 3 + ReadBits(2) times. If code 16 is used before a |
| * non-zero value has been emitted, a value of 8 is repeated. */ |
| repeat = 3 + get_bits(&s->gb, 2); |
| length = prev_code_len; |
| break; |
| case 17: |
| /* Code 17 emits a streak of zeros [3..10], i.e., |
| * 3 + ReadBits(3) times. */ |
| repeat = 3 + get_bits(&s->gb, 3); |
| break; |
| case 18: |
| /* Code 18 emits a streak of zeros of length [11..138], i.e., |
| * 11 + ReadBits(7) times. */ |
| repeat = 11 + get_bits(&s->gb, 7); |
| break; |
| } |
| if (symbol + repeat > alphabet_size) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "invalid symbol %d + repeat %d > alphabet size %d\n", |
| symbol, repeat, alphabet_size); |
| ret = AVERROR_INVALIDDATA; |
| goto finish; |
| } |
| while (repeat-- > 0) |
| code_lengths[symbol++] = length; |
| } |
| } |
| |
| ret = huff_reader_build_canonical(hc, code_lengths, alphabet_size); |
| |
| finish: |
| ff_free_vlc(&code_len_hc.vlc); |
| av_free(code_lengths); |
| return ret; |
| } |
| |
| static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role, |
| int w, int h); |
| |
| #define PARSE_BLOCK_SIZE(w, h) do { \ |
| block_bits = get_bits(&s->gb, 3) + 2; \ |
| blocks_w = FFALIGN((w), 1 << block_bits) >> block_bits; \ |
| blocks_h = FFALIGN((h), 1 << block_bits) >> block_bits; \ |
| } while (0) |
| |
| static int decode_entropy_image(WebPContext *s) |
| { |
| ImageContext *img; |
| int ret, block_bits, width, blocks_w, blocks_h, x, y, max; |
| |
| width = s->width; |
| if (s->reduced_width > 0) |
| width = s->reduced_width; |
| |
| PARSE_BLOCK_SIZE(width, s->height); |
| |
| ret = decode_entropy_coded_image(s, IMAGE_ROLE_ENTROPY, blocks_w, blocks_h); |
| if (ret < 0) |
| return ret; |
| |
| img = &s->image[IMAGE_ROLE_ENTROPY]; |
| img->size_reduction = block_bits; |
| |
| /* the number of huffman groups is determined by the maximum group number |
| * coded in the entropy image */ |
| max = 0; |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| int p0 = GET_PIXEL_COMP(img->frame, x, y, 1); |
| int p1 = GET_PIXEL_COMP(img->frame, x, y, 2); |
| int p = p0 << 8 | p1; |
| max = FFMAX(max, p); |
| } |
| } |
| s->nb_huffman_groups = max + 1; |
| |
| return 0; |
| } |
| |
| static int parse_transform_predictor(WebPContext *s) |
| { |
| int block_bits, blocks_w, blocks_h, ret; |
| |
| PARSE_BLOCK_SIZE(s->width, s->height); |
| |
| ret = decode_entropy_coded_image(s, IMAGE_ROLE_PREDICTOR, blocks_w, |
| blocks_h); |
| if (ret < 0) |
| return ret; |
| |
| s->image[IMAGE_ROLE_PREDICTOR].size_reduction = block_bits; |
| |
| return 0; |
| } |
| |
| static int parse_transform_color(WebPContext *s) |
| { |
| int block_bits, blocks_w, blocks_h, ret; |
| |
| PARSE_BLOCK_SIZE(s->width, s->height); |
| |
| ret = decode_entropy_coded_image(s, IMAGE_ROLE_COLOR_TRANSFORM, blocks_w, |
| blocks_h); |
| if (ret < 0) |
| return ret; |
| |
| s->image[IMAGE_ROLE_COLOR_TRANSFORM].size_reduction = block_bits; |
| |
| return 0; |
| } |
| |
| static int parse_transform_color_indexing(WebPContext *s) |
| { |
| ImageContext *img; |
| int width_bits, index_size, ret, x; |
| uint8_t *ct; |
| |
| index_size = get_bits(&s->gb, 8) + 1; |
| |
| if (index_size <= 2) |
| width_bits = 3; |
| else if (index_size <= 4) |
| width_bits = 2; |
| else if (index_size <= 16) |
| width_bits = 1; |
| else |
| width_bits = 0; |
| |
| ret = decode_entropy_coded_image(s, IMAGE_ROLE_COLOR_INDEXING, |
| index_size, 1); |
| if (ret < 0) |
| return ret; |
| |
| img = &s->image[IMAGE_ROLE_COLOR_INDEXING]; |
| img->size_reduction = width_bits; |
| if (width_bits > 0) |
| s->reduced_width = (s->width + ((1 << width_bits) - 1)) >> width_bits; |
| |
| /* color index values are delta-coded */ |
| ct = img->frame->data[0] + 4; |
| for (x = 4; x < img->frame->width * 4; x++, ct++) |
| ct[0] += ct[-4]; |
| |
| return 0; |
| } |
| |
| static HuffReader *get_huffman_group(WebPContext *s, ImageContext *img, |
| int x, int y) |
| { |
| ImageContext *gimg = &s->image[IMAGE_ROLE_ENTROPY]; |
| int group = 0; |
| |
| if (gimg->size_reduction > 0) { |
| int group_x = x >> gimg->size_reduction; |
| int group_y = y >> gimg->size_reduction; |
| int g0 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 1); |
| int g1 = GET_PIXEL_COMP(gimg->frame, group_x, group_y, 2); |
| group = g0 << 8 | g1; |
| } |
| |
| return &img->huffman_groups[group * HUFFMAN_CODES_PER_META_CODE]; |
| } |
| |
| static av_always_inline void color_cache_put(ImageContext *img, uint32_t c) |
| { |
| uint32_t cache_idx = (0x1E35A7BD * c) >> (32 - img->color_cache_bits); |
| img->color_cache[cache_idx] = c; |
| } |
| |
| static int decode_entropy_coded_image(WebPContext *s, enum ImageRole role, |
| int w, int h) |
| { |
| ImageContext *img; |
| HuffReader *hg; |
| int i, j, ret, x, y, width; |
| |
| img = &s->image[role]; |
| img->role = role; |
| |
| if (!img->frame) { |
| img->frame = av_frame_alloc(); |
| if (!img->frame) |
| return AVERROR(ENOMEM); |
| } |
| |
| img->frame->format = AV_PIX_FMT_ARGB; |
| img->frame->width = w; |
| img->frame->height = h; |
| |
| if (role == IMAGE_ROLE_ARGB && !img->is_alpha_primary) { |
| ThreadFrame pt = { .f = img->frame }; |
| ret = ff_thread_get_buffer(s->avctx, &pt, 0); |
| } else |
| ret = av_frame_get_buffer(img->frame, 1); |
| if (ret < 0) |
| return ret; |
| |
| if (get_bits1(&s->gb)) { |
| img->color_cache_bits = get_bits(&s->gb, 4); |
| if (img->color_cache_bits < 1 || img->color_cache_bits > 11) { |
| av_log(s->avctx, AV_LOG_ERROR, "invalid color cache bits: %d\n", |
| img->color_cache_bits); |
| return AVERROR_INVALIDDATA; |
| } |
| img->color_cache = av_mallocz_array(1 << img->color_cache_bits, |
| sizeof(*img->color_cache)); |
| if (!img->color_cache) |
| return AVERROR(ENOMEM); |
| } else { |
| img->color_cache_bits = 0; |
| } |
| |
| img->nb_huffman_groups = 1; |
| if (role == IMAGE_ROLE_ARGB && get_bits1(&s->gb)) { |
| ret = decode_entropy_image(s); |
| if (ret < 0) |
| return ret; |
| img->nb_huffman_groups = s->nb_huffman_groups; |
| } |
| img->huffman_groups = av_mallocz_array(img->nb_huffman_groups * |
| HUFFMAN_CODES_PER_META_CODE, |
| sizeof(*img->huffman_groups)); |
| if (!img->huffman_groups) |
| return AVERROR(ENOMEM); |
| |
| for (i = 0; i < img->nb_huffman_groups; i++) { |
| hg = &img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE]; |
| for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) { |
| int alphabet_size = alphabet_sizes[j]; |
| if (!j && img->color_cache_bits > 0) |
| alphabet_size += 1 << img->color_cache_bits; |
| |
| if (get_bits1(&s->gb)) { |
| read_huffman_code_simple(s, &hg[j]); |
| } else { |
| ret = read_huffman_code_normal(s, &hg[j], alphabet_size); |
| if (ret < 0) |
| return ret; |
| } |
| } |
| } |
| |
| width = img->frame->width; |
| if (role == IMAGE_ROLE_ARGB && s->reduced_width > 0) |
| width = s->reduced_width; |
| |
| x = 0; y = 0; |
| while (y < img->frame->height) { |
| int v; |
| |
| hg = get_huffman_group(s, img, x, y); |
| v = huff_reader_get_symbol(&hg[HUFF_IDX_GREEN], &s->gb); |
| if (v < NUM_LITERAL_CODES) { |
| /* literal pixel values */ |
| uint8_t *p = GET_PIXEL(img->frame, x, y); |
| p[2] = v; |
| p[1] = huff_reader_get_symbol(&hg[HUFF_IDX_RED], &s->gb); |
| p[3] = huff_reader_get_symbol(&hg[HUFF_IDX_BLUE], &s->gb); |
| p[0] = huff_reader_get_symbol(&hg[HUFF_IDX_ALPHA], &s->gb); |
| if (img->color_cache_bits) |
| color_cache_put(img, AV_RB32(p)); |
| x++; |
| if (x == width) { |
| x = 0; |
| y++; |
| } |
| } else if (v < NUM_LITERAL_CODES + NUM_LENGTH_CODES) { |
| /* LZ77 backwards mapping */ |
| int prefix_code, length, distance, ref_x, ref_y; |
| |
| /* parse length and distance */ |
| prefix_code = v - NUM_LITERAL_CODES; |
| if (prefix_code < 4) { |
| length = prefix_code + 1; |
| } else { |
| int extra_bits = (prefix_code - 2) >> 1; |
| int offset = 2 + (prefix_code & 1) << extra_bits; |
| length = offset + get_bits(&s->gb, extra_bits) + 1; |
| } |
| prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->gb); |
| if (prefix_code > 39) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "distance prefix code too large: %d\n", prefix_code); |
| return AVERROR_INVALIDDATA; |
| } |
| if (prefix_code < 4) { |
| distance = prefix_code + 1; |
| } else { |
| int extra_bits = prefix_code - 2 >> 1; |
| int offset = 2 + (prefix_code & 1) << extra_bits; |
| distance = offset + get_bits(&s->gb, extra_bits) + 1; |
| } |
| |
| /* find reference location */ |
| if (distance <= NUM_SHORT_DISTANCES) { |
| int xi = lz77_distance_offsets[distance - 1][0]; |
| int yi = lz77_distance_offsets[distance - 1][1]; |
| distance = FFMAX(1, xi + yi * width); |
| } else { |
| distance -= NUM_SHORT_DISTANCES; |
| } |
| ref_x = x; |
| ref_y = y; |
| if (distance <= x) { |
| ref_x -= distance; |
| distance = 0; |
| } else { |
| ref_x = 0; |
| distance -= x; |
| } |
| while (distance >= width) { |
| ref_y--; |
| distance -= width; |
| } |
| if (distance > 0) { |
| ref_x = width - distance; |
| ref_y--; |
| } |
| ref_x = FFMAX(0, ref_x); |
| ref_y = FFMAX(0, ref_y); |
| |
| /* copy pixels |
| * source and dest regions can overlap and wrap lines, so just |
| * copy per-pixel */ |
| for (i = 0; i < length; i++) { |
| uint8_t *p_ref = GET_PIXEL(img->frame, ref_x, ref_y); |
| uint8_t *p = GET_PIXEL(img->frame, x, y); |
| |
| AV_COPY32(p, p_ref); |
| if (img->color_cache_bits) |
| color_cache_put(img, AV_RB32(p)); |
| x++; |
| ref_x++; |
| if (x == width) { |
| x = 0; |
| y++; |
| } |
| if (ref_x == width) { |
| ref_x = 0; |
| ref_y++; |
| } |
| if (y == img->frame->height || ref_y == img->frame->height) |
| break; |
| } |
| } else { |
| /* read from color cache */ |
| uint8_t *p = GET_PIXEL(img->frame, x, y); |
| int cache_idx = v - (NUM_LITERAL_CODES + NUM_LENGTH_CODES); |
| |
| if (!img->color_cache_bits) { |
| av_log(s->avctx, AV_LOG_ERROR, "color cache not found\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| if (cache_idx >= 1 << img->color_cache_bits) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "color cache index out-of-bounds\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| AV_WB32(p, img->color_cache[cache_idx]); |
| x++; |
| if (x == width) { |
| x = 0; |
| y++; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* PRED_MODE_BLACK */ |
| 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) |
| { |
| AV_WB32(p, 0xFF000000); |
| } |
| |
| /* PRED_MODE_L */ |
| 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) |
| { |
| AV_COPY32(p, p_l); |
| } |
| |
| /* PRED_MODE_T */ |
| 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) |
| { |
| AV_COPY32(p, p_t); |
| } |
| |
| /* PRED_MODE_TR */ |
| 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) |
| { |
| AV_COPY32(p, p_tr); |
| } |
| |
| /* PRED_MODE_TL */ |
| 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) |
| { |
| AV_COPY32(p, p_tl); |
| } |
| |
| /* PRED_MODE_AVG_T_AVG_L_TR */ |
| 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) |
| { |
| p[0] = p_t[0] + (p_l[0] + p_tr[0] >> 1) >> 1; |
| p[1] = p_t[1] + (p_l[1] + p_tr[1] >> 1) >> 1; |
| p[2] = p_t[2] + (p_l[2] + p_tr[2] >> 1) >> 1; |
| p[3] = p_t[3] + (p_l[3] + p_tr[3] >> 1) >> 1; |
| } |
| |
| /* PRED_MODE_AVG_L_TL */ |
| 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) |
| { |
| p[0] = p_l[0] + p_tl[0] >> 1; |
| p[1] = p_l[1] + p_tl[1] >> 1; |
| p[2] = p_l[2] + p_tl[2] >> 1; |
| p[3] = p_l[3] + p_tl[3] >> 1; |
| } |
| |
| /* PRED_MODE_AVG_L_T */ |
| 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) |
| { |
| p[0] = p_l[0] + p_t[0] >> 1; |
| p[1] = p_l[1] + p_t[1] >> 1; |
| p[2] = p_l[2] + p_t[2] >> 1; |
| p[3] = p_l[3] + p_t[3] >> 1; |
| } |
| |
| /* PRED_MODE_AVG_TL_T */ |
| 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) |
| { |
| p[0] = p_tl[0] + p_t[0] >> 1; |
| p[1] = p_tl[1] + p_t[1] >> 1; |
| p[2] = p_tl[2] + p_t[2] >> 1; |
| p[3] = p_tl[3] + p_t[3] >> 1; |
| } |
| |
| /* PRED_MODE_AVG_T_TR */ |
| 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) |
| { |
| p[0] = p_t[0] + p_tr[0] >> 1; |
| p[1] = p_t[1] + p_tr[1] >> 1; |
| p[2] = p_t[2] + p_tr[2] >> 1; |
| p[3] = p_t[3] + p_tr[3] >> 1; |
| } |
| |
| /* PRED_MODE_AVG_AVG_L_TL_AVG_T_TR */ |
| 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) |
| { |
| p[0] = (p_l[0] + p_tl[0] >> 1) + (p_t[0] + p_tr[0] >> 1) >> 1; |
| p[1] = (p_l[1] + p_tl[1] >> 1) + (p_t[1] + p_tr[1] >> 1) >> 1; |
| p[2] = (p_l[2] + p_tl[2] >> 1) + (p_t[2] + p_tr[2] >> 1) >> 1; |
| p[3] = (p_l[3] + p_tl[3] >> 1) + (p_t[3] + p_tr[3] >> 1) >> 1; |
| } |
| |
| /* PRED_MODE_SELECT */ |
| 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) |
| { |
| int diff = (FFABS(p_l[0] - p_tl[0]) - FFABS(p_t[0] - p_tl[0])) + |
| (FFABS(p_l[1] - p_tl[1]) - FFABS(p_t[1] - p_tl[1])) + |
| (FFABS(p_l[2] - p_tl[2]) - FFABS(p_t[2] - p_tl[2])) + |
| (FFABS(p_l[3] - p_tl[3]) - FFABS(p_t[3] - p_tl[3])); |
| if (diff <= 0) |
| AV_COPY32(p, p_t); |
| else |
| AV_COPY32(p, p_l); |
| } |
| |
| /* PRED_MODE_ADD_SUBTRACT_FULL */ |
| 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) |
| { |
| p[0] = av_clip_uint8(p_l[0] + p_t[0] - p_tl[0]); |
| p[1] = av_clip_uint8(p_l[1] + p_t[1] - p_tl[1]); |
| p[2] = av_clip_uint8(p_l[2] + p_t[2] - p_tl[2]); |
| p[3] = av_clip_uint8(p_l[3] + p_t[3] - p_tl[3]); |
| } |
| |
| static av_always_inline uint8_t clamp_add_subtract_half(int a, int b, int c) |
| { |
| int d = a + b >> 1; |
| return av_clip_uint8(d + (d - c) / 2); |
| } |
| |
| /* PRED_MODE_ADD_SUBTRACT_HALF */ |
| 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) |
| { |
| p[0] = clamp_add_subtract_half(p_l[0], p_t[0], p_tl[0]); |
| p[1] = clamp_add_subtract_half(p_l[1], p_t[1], p_tl[1]); |
| p[2] = clamp_add_subtract_half(p_l[2], p_t[2], p_tl[2]); |
| p[3] = clamp_add_subtract_half(p_l[3], p_t[3], p_tl[3]); |
| } |
| |
| typedef 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); |
| |
| static const inv_predict_func inverse_predict[14] = { |
| inv_predict_0, inv_predict_1, inv_predict_2, inv_predict_3, |
| inv_predict_4, inv_predict_5, inv_predict_6, inv_predict_7, |
| inv_predict_8, inv_predict_9, inv_predict_10, inv_predict_11, |
| inv_predict_12, inv_predict_13, |
| }; |
| |
| static void inverse_prediction(AVFrame *frame, enum PredictionMode m, int x, int y) |
| { |
| uint8_t *dec, *p_l, *p_tl, *p_t, *p_tr; |
| uint8_t p[4]; |
| |
| dec = GET_PIXEL(frame, x, y); |
| p_l = GET_PIXEL(frame, x - 1, y); |
| p_tl = GET_PIXEL(frame, x - 1, y - 1); |
| p_t = GET_PIXEL(frame, x, y - 1); |
| if (x == frame->width - 1) |
| p_tr = GET_PIXEL(frame, 0, y); |
| else |
| p_tr = GET_PIXEL(frame, x + 1, y - 1); |
| |
| inverse_predict[m](p, p_l, p_tl, p_t, p_tr); |
| |
| dec[0] += p[0]; |
| dec[1] += p[1]; |
| dec[2] += p[2]; |
| dec[3] += p[3]; |
| } |
| |
| static int apply_predictor_transform(WebPContext *s) |
| { |
| ImageContext *img = &s->image[IMAGE_ROLE_ARGB]; |
| ImageContext *pimg = &s->image[IMAGE_ROLE_PREDICTOR]; |
| int x, y; |
| |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| int tx = x >> pimg->size_reduction; |
| int ty = y >> pimg->size_reduction; |
| enum PredictionMode m = GET_PIXEL_COMP(pimg->frame, tx, ty, 2); |
| |
| if (x == 0) { |
| if (y == 0) |
| m = PRED_MODE_BLACK; |
| else |
| m = PRED_MODE_T; |
| } else if (y == 0) |
| m = PRED_MODE_L; |
| |
| if (m > 13) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "invalid predictor mode: %d\n", m); |
| return AVERROR_INVALIDDATA; |
| } |
| inverse_prediction(img->frame, m, x, y); |
| } |
| } |
| return 0; |
| } |
| |
| static av_always_inline uint8_t color_transform_delta(uint8_t color_pred, |
| uint8_t color) |
| { |
| return (int)ff_u8_to_s8(color_pred) * ff_u8_to_s8(color) >> 5; |
| } |
| |
| static int apply_color_transform(WebPContext *s) |
| { |
| ImageContext *img, *cimg; |
| int x, y, cx, cy; |
| uint8_t *p, *cp; |
| |
| img = &s->image[IMAGE_ROLE_ARGB]; |
| cimg = &s->image[IMAGE_ROLE_COLOR_TRANSFORM]; |
| |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| cx = x >> cimg->size_reduction; |
| cy = y >> cimg->size_reduction; |
| cp = GET_PIXEL(cimg->frame, cx, cy); |
| p = GET_PIXEL(img->frame, x, y); |
| |
| p[1] += color_transform_delta(cp[3], p[2]); |
| p[3] += color_transform_delta(cp[2], p[2]) + |
| color_transform_delta(cp[1], p[1]); |
| } |
| } |
| return 0; |
| } |
| |
| static int apply_subtract_green_transform(WebPContext *s) |
| { |
| int x, y; |
| ImageContext *img = &s->image[IMAGE_ROLE_ARGB]; |
| |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| uint8_t *p = GET_PIXEL(img->frame, x, y); |
| p[1] += p[2]; |
| p[3] += p[2]; |
| } |
| } |
| return 0; |
| } |
| |
| static int apply_color_indexing_transform(WebPContext *s) |
| { |
| ImageContext *img; |
| ImageContext *pal; |
| int i, x, y; |
| uint8_t *p; |
| |
| img = &s->image[IMAGE_ROLE_ARGB]; |
| pal = &s->image[IMAGE_ROLE_COLOR_INDEXING]; |
| |
| if (pal->size_reduction > 0) { |
| GetBitContext gb_g; |
| uint8_t *line; |
| int pixel_bits = 8 >> pal->size_reduction; |
| |
| line = av_malloc(img->frame->linesize[0]); |
| if (!line) |
| return AVERROR(ENOMEM); |
| |
| for (y = 0; y < img->frame->height; y++) { |
| p = GET_PIXEL(img->frame, 0, y); |
| memcpy(line, p, img->frame->linesize[0]); |
| init_get_bits(&gb_g, line, img->frame->linesize[0] * 8); |
| skip_bits(&gb_g, 16); |
| i = 0; |
| for (x = 0; x < img->frame->width; x++) { |
| p = GET_PIXEL(img->frame, x, y); |
| p[2] = get_bits(&gb_g, pixel_bits); |
| i++; |
| if (i == 1 << pal->size_reduction) { |
| skip_bits(&gb_g, 24); |
| i = 0; |
| } |
| } |
| } |
| av_free(line); |
| } |
| |
| // switch to local palette if it's worth initializing it |
| if (img->frame->height * img->frame->width > 300) { |
| uint8_t palette[256 * 4]; |
| const int size = pal->frame->width * 4; |
| av_assert0(size <= 1024U); |
| memcpy(palette, GET_PIXEL(pal->frame, 0, 0), size); // copy palette |
| // set extra entries to transparent black |
| memset(palette + size, 0, 256 * 4 - size); |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| p = GET_PIXEL(img->frame, x, y); |
| i = p[2]; |
| AV_COPY32(p, &palette[i * 4]); |
| } |
| } |
| } else { |
| for (y = 0; y < img->frame->height; y++) { |
| for (x = 0; x < img->frame->width; x++) { |
| p = GET_PIXEL(img->frame, x, y); |
| i = p[2]; |
| if (i >= pal->frame->width) { |
| AV_WB32(p, 0x00000000); |
| } else { |
| const uint8_t *pi = GET_PIXEL(pal->frame, i, 0); |
| AV_COPY32(p, pi); |
| } |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| 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) |
| { |
| WebPContext *s = avctx->priv_data; |
| int w, h, ret, i, used; |
| |
| if (!is_alpha_chunk) { |
| s->lossless = 1; |
| avctx->pix_fmt = AV_PIX_FMT_ARGB; |
| } |
| |
| ret = init_get_bits8(&s->gb, data_start, data_size); |
| if (ret < 0) |
| return ret; |
| |
| if (!is_alpha_chunk) { |
| if (get_bits(&s->gb, 8) != 0x2F) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless signature\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| w = get_bits(&s->gb, 14) + 1; |
| h = get_bits(&s->gb, 14) + 1; |
| if (s->width && s->width != w) { |
| av_log(avctx, AV_LOG_WARNING, "Width mismatch. %d != %d\n", |
| s->width, w); |
| } |
| s->width = w; |
| if (s->height && s->height != h) { |
| av_log(avctx, AV_LOG_WARNING, "Height mismatch. %d != %d\n", |
| s->width, w); |
| } |
| s->height = h; |
| |
| ret = ff_set_dimensions(avctx, s->width, s->height); |
| if (ret < 0) |
| return ret; |
| |
| s->has_alpha = get_bits1(&s->gb); |
| |
| if (get_bits(&s->gb, 3) != 0x0) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless version\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| } else { |
| if (!s->width || !s->height) |
| return AVERROR_BUG; |
| w = s->width; |
| h = s->height; |
| } |
| |
| /* parse transformations */ |
| s->nb_transforms = 0; |
| s->reduced_width = 0; |
| used = 0; |
| while (get_bits1(&s->gb)) { |
| enum TransformType transform = get_bits(&s->gb, 2); |
| if (used & (1 << transform)) { |
| av_log(avctx, AV_LOG_ERROR, "Transform %d used more than once\n", |
| transform); |
| ret = AVERROR_INVALIDDATA; |
| goto free_and_return; |
| } |
| used |= (1 << transform); |
| s->transforms[s->nb_transforms++] = transform; |
| switch (transform) { |
| case PREDICTOR_TRANSFORM: |
| ret = parse_transform_predictor(s); |
| break; |
| case COLOR_TRANSFORM: |
| ret = parse_transform_color(s); |
| break; |
| case COLOR_INDEXING_TRANSFORM: |
| ret = parse_transform_color_indexing(s); |
| break; |
| } |
| if (ret < 0) |
| goto free_and_return; |
| } |
| |
| /* decode primary image */ |
| s->image[IMAGE_ROLE_ARGB].frame = p; |
| if (is_alpha_chunk) |
| s->image[IMAGE_ROLE_ARGB].is_alpha_primary = 1; |
| ret = decode_entropy_coded_image(s, IMAGE_ROLE_ARGB, w, h); |
| if (ret < 0) |
| goto free_and_return; |
| |
| /* apply transformations */ |
| for (i = s->nb_transforms - 1; i >= 0; i--) { |
| switch (s->transforms[i]) { |
| case PREDICTOR_TRANSFORM: |
| ret = apply_predictor_transform(s); |
| break; |
| case COLOR_TRANSFORM: |
| ret = apply_color_transform(s); |
| break; |
| case SUBTRACT_GREEN: |
| ret = apply_subtract_green_transform(s); |
| break; |
| case COLOR_INDEXING_TRANSFORM: |
| ret = apply_color_indexing_transform(s); |
| break; |
| } |
| if (ret < 0) |
| goto free_and_return; |
| } |
| |
| *got_frame = 1; |
| p->pict_type = AV_PICTURE_TYPE_I; |
| p->key_frame = 1; |
| ret = data_size; |
| |
| free_and_return: |
| for (i = 0; i < IMAGE_ROLE_NB; i++) |
| image_ctx_free(&s->image[i]); |
| |
| return ret; |
| } |
| |
| static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m) |
| { |
| int x, y, ls; |
| uint8_t *dec; |
| |
| ls = frame->linesize[3]; |
| |
| /* filter first row using horizontal filter */ |
| dec = frame->data[3] + 1; |
| for (x = 1; x < frame->width; x++, dec++) |
| *dec += *(dec - 1); |
| |
| /* filter first column using vertical filter */ |
| dec = frame->data[3] + ls; |
| for (y = 1; y < frame->height; y++, dec += ls) |
| *dec += *(dec - ls); |
| |
| /* filter the rest using the specified filter */ |
| switch (m) { |
| case ALPHA_FILTER_HORIZONTAL: |
| for (y = 1; y < frame->height; y++) { |
| dec = frame->data[3] + y * ls + 1; |
| for (x = 1; x < frame->width; x++, dec++) |
| *dec += *(dec - 1); |
| } |
| break; |
| case ALPHA_FILTER_VERTICAL: |
| for (y = 1; y < frame->height; y++) { |
| dec = frame->data[3] + y * ls + 1; |
| for (x = 1; x < frame->width; x++, dec++) |
| *dec += *(dec - ls); |
| } |
| break; |
| case ALPHA_FILTER_GRADIENT: |
| for (y = 1; y < frame->height; y++) { |
| dec = frame->data[3] + y * ls + 1; |
| for (x = 1; x < frame->width; x++, dec++) |
| dec[0] += av_clip_uint8(*(dec - 1) + *(dec - ls) - *(dec - ls - 1)); |
| } |
| break; |
| } |
| } |
| |
| static int vp8_lossy_decode_alpha(AVCodecContext *avctx, AVFrame *p, |
| uint8_t *data_start, |
| unsigned int data_size) |
| { |
| WebPContext *s = avctx->priv_data; |
| int x, y, ret; |
| |
| if (s->alpha_compression == ALPHA_COMPRESSION_NONE) { |
| GetByteContext gb; |
| |
| bytestream2_init(&gb, data_start, data_size); |
| for (y = 0; y < s->height; y++) |
| bytestream2_get_buffer(&gb, p->data[3] + p->linesize[3] * y, |
| s->width); |
| } else if (s->alpha_compression == ALPHA_COMPRESSION_VP8L) { |
| uint8_t *ap, *pp; |
| int alpha_got_frame = 0; |
| |
| s->alpha_frame = av_frame_alloc(); |
| if (!s->alpha_frame) |
| return AVERROR(ENOMEM); |
| |
| ret = vp8_lossless_decode_frame(avctx, s->alpha_frame, &alpha_got_frame, |
| data_start, data_size, 1); |
| if (ret < 0) { |
| av_frame_free(&s->alpha_frame); |
| return ret; |
| } |
| if (!alpha_got_frame) { |
| av_frame_free(&s->alpha_frame); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| /* copy green component of alpha image to alpha plane of primary image */ |
| for (y = 0; y < s->height; y++) { |
| ap = GET_PIXEL(s->alpha_frame, 0, y) + 2; |
| pp = p->data[3] + p->linesize[3] * y; |
| for (x = 0; x < s->width; x++) { |
| *pp = *ap; |
| pp++; |
| ap += 4; |
| } |
| } |
| av_frame_free(&s->alpha_frame); |
| } |
| |
| /* apply alpha filtering */ |
| if (s->alpha_filter) |
| alpha_inverse_prediction(p, s->alpha_filter); |
| |
| return 0; |
| } |
| |
| static int vp8_lossy_decode_frame(AVCodecContext *avctx, AVFrame *p, |
| int *got_frame, uint8_t *data_start, |
| unsigned int data_size) |
| { |
| WebPContext *s = avctx->priv_data; |
| AVPacket pkt; |
| int ret; |
| |
| if (!s->initialized) { |
| ff_vp8_decode_init(avctx); |
| s->initialized = 1; |
| if (s->has_alpha) |
| avctx->pix_fmt = AV_PIX_FMT_YUVA420P; |
| } |
| s->lossless = 0; |
| |
| if (data_size > INT_MAX) { |
| av_log(avctx, AV_LOG_ERROR, "unsupported chunk size\n"); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| av_init_packet(&pkt); |
| pkt.data = data_start; |
| pkt.size = data_size; |
| |
| ret = ff_vp8_decode_frame(avctx, p, got_frame, &pkt); |
| if (s->has_alpha) { |
| ret = vp8_lossy_decode_alpha(avctx, p, s->alpha_data, |
| s->alpha_data_size); |
| if (ret < 0) |
| return ret; |
| } |
| return ret; |
| } |
| |
| static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
| AVPacket *avpkt) |
| { |
| AVFrame * const p = data; |
| WebPContext *s = avctx->priv_data; |
| GetByteContext gb; |
| int ret; |
| uint32_t chunk_type, chunk_size; |
| int vp8x_flags = 0; |
| |
| s->avctx = avctx; |
| s->width = 0; |
| s->height = 0; |
| *got_frame = 0; |
| s->has_alpha = 0; |
| s->has_exif = 0; |
| bytestream2_init(&gb, avpkt->data, avpkt->size); |
| |
| if (bytestream2_get_bytes_left(&gb) < 12) |
| return AVERROR_INVALIDDATA; |
| |
| if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) { |
| av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| chunk_size = bytestream2_get_le32(&gb); |
| if (bytestream2_get_bytes_left(&gb) < chunk_size) |
| return AVERROR_INVALIDDATA; |
| |
| if (bytestream2_get_le32(&gb) != MKTAG('W', 'E', 'B', 'P')) { |
| av_log(avctx, AV_LOG_ERROR, "missing WEBP tag\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| av_dict_free(&s->exif_metadata); |
| while (bytestream2_get_bytes_left(&gb) > 8) { |
| char chunk_str[5] = { 0 }; |
| |
| chunk_type = bytestream2_get_le32(&gb); |
| chunk_size = bytestream2_get_le32(&gb); |
| if (chunk_size == UINT32_MAX) |
| return AVERROR_INVALIDDATA; |
| chunk_size += chunk_size & 1; |
| |
| if (bytestream2_get_bytes_left(&gb) < chunk_size) |
| return AVERROR_INVALIDDATA; |
| |
| switch (chunk_type) { |
| case MKTAG('V', 'P', '8', ' '): |
| if (!*got_frame) { |
| ret = vp8_lossy_decode_frame(avctx, p, got_frame, |
| avpkt->data + bytestream2_tell(&gb), |
| chunk_size); |
| if (ret < 0) |
| return ret; |
| } |
| bytestream2_skip(&gb, chunk_size); |
| break; |
| case MKTAG('V', 'P', '8', 'L'): |
| if (!*got_frame) { |
| ret = vp8_lossless_decode_frame(avctx, p, got_frame, |
| avpkt->data + bytestream2_tell(&gb), |
| chunk_size, 0); |
| if (ret < 0) |
| return ret; |
| avctx->properties |= FF_CODEC_PROPERTY_LOSSLESS; |
| } |
| bytestream2_skip(&gb, chunk_size); |
| break; |
| case MKTAG('V', 'P', '8', 'X'): |
| vp8x_flags = bytestream2_get_byte(&gb); |
| bytestream2_skip(&gb, 3); |
| s->width = bytestream2_get_le24(&gb) + 1; |
| s->height = bytestream2_get_le24(&gb) + 1; |
| ret = av_image_check_size(s->width, s->height, 0, avctx); |
| if (ret < 0) |
| return ret; |
| break; |
| case MKTAG('A', 'L', 'P', 'H'): { |
| int alpha_header, filter_m, compression; |
| |
| if (!(vp8x_flags & VP8X_FLAG_ALPHA)) { |
| av_log(avctx, AV_LOG_WARNING, |
| "ALPHA chunk present, but alpha bit not set in the " |
| "VP8X header\n"); |
| } |
| if (chunk_size == 0) { |
| av_log(avctx, AV_LOG_ERROR, "invalid ALPHA chunk size\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| alpha_header = bytestream2_get_byte(&gb); |
| s->alpha_data = avpkt->data + bytestream2_tell(&gb); |
| s->alpha_data_size = chunk_size - 1; |
| bytestream2_skip(&gb, s->alpha_data_size); |
| |
| filter_m = (alpha_header >> 2) & 0x03; |
| compression = alpha_header & 0x03; |
| |
| if (compression > ALPHA_COMPRESSION_VP8L) { |
| av_log(avctx, AV_LOG_VERBOSE, |
| "skipping unsupported ALPHA chunk\n"); |
| } else { |
| s->has_alpha = 1; |
| s->alpha_compression = compression; |
| s->alpha_filter = filter_m; |
| } |
| |
| break; |
| } |
| case MKTAG('E', 'X', 'I', 'F'): { |
| int le, ifd_offset, exif_offset = bytestream2_tell(&gb); |
| GetByteContext exif_gb; |
| |
| if (s->has_exif) { |
| av_log(avctx, AV_LOG_VERBOSE, "Ignoring extra EXIF chunk\n"); |
| goto exif_end; |
| } |
| if (!(vp8x_flags & VP8X_FLAG_EXIF_METADATA)) |
| av_log(avctx, AV_LOG_WARNING, |
| "EXIF chunk present, but Exif bit not set in the " |
| "VP8X header\n"); |
| |
| s->has_exif = 1; |
| bytestream2_init(&exif_gb, avpkt->data + exif_offset, |
| avpkt->size - exif_offset); |
| if (ff_tdecode_header(&exif_gb, &le, &ifd_offset) < 0) { |
| av_log(avctx, AV_LOG_ERROR, "invalid TIFF header " |
| "in Exif data\n"); |
| goto exif_end; |
| } |
| |
| bytestream2_seek(&exif_gb, ifd_offset, SEEK_SET); |
| if (avpriv_exif_decode_ifd(avctx, &exif_gb, le, 0, &s->exif_metadata) < 0) { |
| av_log(avctx, AV_LOG_ERROR, "error decoding Exif data\n"); |
| goto exif_end; |
| } |
| |
| av_dict_copy(avpriv_frame_get_metadatap(data), s->exif_metadata, 0); |
| |
| exif_end: |
| av_dict_free(&s->exif_metadata); |
| bytestream2_skip(&gb, chunk_size); |
| break; |
| } |
| case MKTAG('I', 'C', 'C', 'P'): |
| case MKTAG('A', 'N', 'I', 'M'): |
| case MKTAG('A', 'N', 'M', 'F'): |
| case MKTAG('X', 'M', 'P', ' '): |
| AV_WL32(chunk_str, chunk_type); |
| av_log(avctx, AV_LOG_VERBOSE, "skipping unsupported chunk: %s\n", |
| chunk_str); |
| bytestream2_skip(&gb, chunk_size); |
| break; |
| default: |
| AV_WL32(chunk_str, chunk_type); |
| av_log(avctx, AV_LOG_VERBOSE, "skipping unknown chunk: %s\n", |
| chunk_str); |
| bytestream2_skip(&gb, chunk_size); |
| break; |
| } |
| } |
| |
| if (!*got_frame) { |
| av_log(avctx, AV_LOG_ERROR, "image data not found\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| return avpkt->size; |
| } |
| |
| static av_cold int webp_decode_close(AVCodecContext *avctx) |
| { |
| WebPContext *s = avctx->priv_data; |
| |
| if (s->initialized) |
| return ff_vp8_decode_free(avctx); |
| |
| return 0; |
| } |
| |
| AVCodec ff_webp_decoder = { |
| .name = "webp", |
| .long_name = NULL_IF_CONFIG_SMALL("WebP image"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_WEBP, |
| .priv_data_size = sizeof(WebPContext), |
| .decode = webp_decode_frame, |
| .close = webp_decode_close, |
| .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS, |
| }; |
