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1479 lines
47 KiB
1479 lines
47 KiB
/* |
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* WebP (.webp) image decoder |
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* Copyright (c) 2013 Aneesh Dogra <aneesh@sugarlabs.org> |
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* Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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|
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/** |
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* @file |
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* WebP image decoder |
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* |
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* @author Aneesh Dogra <aneesh@sugarlabs.org> |
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* Container and Lossy decoding |
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* |
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* @author Justin Ruggles <justin.ruggles@gmail.com> |
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* Lossless decoder |
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* Compressed alpha for lossy |
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* |
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* Unimplemented: |
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* - Animation |
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* - ICC profile |
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* - Exif and XMP metadata |
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*/ |
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|
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#include "libavutil/imgutils.h" |
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|
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#define BITSTREAM_READER_LE |
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#include "avcodec.h" |
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#include "bitstream.h" |
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#include "bytestream.h" |
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#include "internal.h" |
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#include "thread.h" |
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#include "vp8.h" |
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|
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#define VP8X_FLAG_ANIMATION 0x02 |
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#define VP8X_FLAG_XMP_METADATA 0x04 |
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#define VP8X_FLAG_EXIF_METADATA 0x08 |
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#define VP8X_FLAG_ALPHA 0x10 |
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#define VP8X_FLAG_ICC 0x20 |
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|
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#define MAX_PALETTE_SIZE 256 |
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#define MAX_CACHE_BITS 11 |
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#define NUM_CODE_LENGTH_CODES 19 |
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#define HUFFMAN_CODES_PER_META_CODE 5 |
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#define NUM_LITERAL_CODES 256 |
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#define NUM_LENGTH_CODES 24 |
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#define NUM_DISTANCE_CODES 40 |
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#define NUM_SHORT_DISTANCES 120 |
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#define MAX_HUFFMAN_CODE_LENGTH 15 |
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|
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static const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE] = { |
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NUM_LITERAL_CODES + NUM_LENGTH_CODES, |
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NUM_LITERAL_CODES, NUM_LITERAL_CODES, NUM_LITERAL_CODES, |
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NUM_DISTANCE_CODES |
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}; |
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|
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static const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES] = { |
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17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 |
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}; |
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|
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static const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2] = { |
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{ 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 }, |
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{ 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 }, |
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{ 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 }, |
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{ 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 }, |
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{ 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 }, |
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{ 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 }, |
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{ 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 }, |
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{ 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 }, |
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{ 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 }, |
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{ 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 }, |
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{ 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 }, |
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{ 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 }, |
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{ 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 }, |
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{ -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 }, |
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{ -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 } |
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}; |
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|
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enum AlphaCompression { |
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ALPHA_COMPRESSION_NONE, |
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ALPHA_COMPRESSION_VP8L, |
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}; |
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|
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enum AlphaFilter { |
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ALPHA_FILTER_NONE, |
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ALPHA_FILTER_HORIZONTAL, |
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ALPHA_FILTER_VERTICAL, |
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ALPHA_FILTER_GRADIENT, |
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}; |
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|
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enum TransformType { |
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PREDICTOR_TRANSFORM = 0, |
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COLOR_TRANSFORM = 1, |
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SUBTRACT_GREEN = 2, |
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COLOR_INDEXING_TRANSFORM = 3, |
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}; |
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|
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enum PredictionMode { |
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PRED_MODE_BLACK, |
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PRED_MODE_L, |
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PRED_MODE_T, |
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PRED_MODE_TR, |
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PRED_MODE_TL, |
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PRED_MODE_AVG_T_AVG_L_TR, |
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PRED_MODE_AVG_L_TL, |
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PRED_MODE_AVG_L_T, |
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PRED_MODE_AVG_TL_T, |
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PRED_MODE_AVG_T_TR, |
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PRED_MODE_AVG_AVG_L_TL_AVG_T_TR, |
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PRED_MODE_SELECT, |
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PRED_MODE_ADD_SUBTRACT_FULL, |
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PRED_MODE_ADD_SUBTRACT_HALF, |
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}; |
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|
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enum HuffmanIndex { |
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HUFF_IDX_GREEN = 0, |
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HUFF_IDX_RED = 1, |
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HUFF_IDX_BLUE = 2, |
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HUFF_IDX_ALPHA = 3, |
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HUFF_IDX_DIST = 4 |
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}; |
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|
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/* The structure of WebP lossless is an optional series of transformation data, |
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* followed by the primary image. The primary image also optionally contains |
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* an entropy group mapping if there are multiple entropy groups. There is a |
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* basic image type called an "entropy coded image" that is used for all of |
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* these. The type of each entropy coded image is referred to by the |
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* specification as its role. */ |
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enum ImageRole { |
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/* Primary Image: Stores the actual pixels of the image. */ |
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IMAGE_ROLE_ARGB, |
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|
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/* Entropy Image: Defines which Huffman group to use for different areas of |
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* the primary image. */ |
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IMAGE_ROLE_ENTROPY, |
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|
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/* Predictors: Defines which predictor type to use for different areas of |
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* the primary image. */ |
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IMAGE_ROLE_PREDICTOR, |
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|
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/* Color Transform Data: Defines the color transformation for different |
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* areas of the primary image. */ |
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IMAGE_ROLE_COLOR_TRANSFORM, |
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|
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/* Color Index: Stored as an image of height == 1. */ |
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IMAGE_ROLE_COLOR_INDEXING, |
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|
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IMAGE_ROLE_NB, |
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}; |
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|
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typedef struct HuffReader { |
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VLC vlc; /* Huffman decoder context */ |
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int simple; /* whether to use simple mode */ |
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int nb_symbols; /* number of coded symbols */ |
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uint16_t simple_symbols[2]; /* symbols for simple mode */ |
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} HuffReader; |
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|
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typedef struct ImageContext { |
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enum ImageRole role; /* role of this image */ |
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AVFrame *frame; /* AVFrame for data */ |
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int color_cache_bits; /* color cache size, log2 */ |
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uint32_t *color_cache; /* color cache data */ |
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int nb_huffman_groups; /* number of huffman groups */ |
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HuffReader *huffman_groups; /* reader for each huffman group */ |
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int size_reduction; /* relative size compared to primary image, log2 */ |
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int is_alpha_primary; |
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} ImageContext; |
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|
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typedef struct WebPContext { |
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VP8Context v; /* VP8 Context used for lossy decoding */ |
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BitstreamContext bc; /* bitstream reader for main image chunk */ |
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AVFrame *alpha_frame; /* AVFrame for alpha data decompressed from VP8L */ |
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AVCodecContext *avctx; /* parent AVCodecContext */ |
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int initialized; /* set once the VP8 context is initialized */ |
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int has_alpha; /* has a separate alpha chunk */ |
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enum AlphaCompression alpha_compression; /* compression type for alpha chunk */ |
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enum AlphaFilter alpha_filter; /* filtering method for alpha chunk */ |
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uint8_t *alpha_data; /* alpha chunk data */ |
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int alpha_data_size; /* alpha chunk data size */ |
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int width; /* image width */ |
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int height; /* image height */ |
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int lossless; /* indicates lossless or lossy */ |
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|
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int nb_transforms; /* number of transforms */ |
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enum TransformType transforms[4]; /* transformations used in the image, in order */ |
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int reduced_width; /* reduced width for index image, if applicable */ |
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int nb_huffman_groups; /* number of huffman groups in the primary image */ |
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ImageContext image[IMAGE_ROLE_NB]; /* image context for each role */ |
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} WebPContext; |
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|
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#define GET_PIXEL(frame, x, y) \ |
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((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x)) |
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|
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#define GET_PIXEL_COMP(frame, x, y, c) \ |
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(*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c)) |
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|
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static void image_ctx_free(ImageContext *img) |
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{ |
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int i, j; |
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|
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av_free(img->color_cache); |
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if (img->role != IMAGE_ROLE_ARGB && !img->is_alpha_primary) |
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av_frame_free(&img->frame); |
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if (img->huffman_groups) { |
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for (i = 0; i < img->nb_huffman_groups; i++) { |
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for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; j++) |
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ff_free_vlc(&img->huffman_groups[i * HUFFMAN_CODES_PER_META_CODE + j].vlc); |
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} |
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av_free(img->huffman_groups); |
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} |
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memset(img, 0, sizeof(*img)); |
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} |
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|
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/* Differs from get_vlc2() in the following ways: |
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* - codes are bit-reversed |
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* - assumes 8-bit table to make reversal simpler |
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* - assumes max depth of 2 since the max code length for WebP is 15 |
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*/ |
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static av_always_inline int webp_get_vlc(BitstreamContext *bc, VLC_TYPE (*table)[2]) |
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{ |
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int n, nb_bits; |
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unsigned int index; |
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int code; |
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|
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index = bitstream_peek(bc, 8); |
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index = ff_reverse[index]; |
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code = table[index][0]; |
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n = table[index][1]; |
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|
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if (n < 0) { |
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bitstream_skip(bc, 8); |
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nb_bits = -n; |
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index = bitstream_peek(bc, nb_bits); |
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index = (ff_reverse[index] >> (8 - nb_bits)) + code; |
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code = table[index][0]; |
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n = table[index][1]; |
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} |
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bitstream_skip(bc, n); |
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|
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return code; |
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} |
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|
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static int huff_reader_get_symbol(HuffReader *r, BitstreamContext *bc) |
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{ |
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if (r->simple) { |
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if (r->nb_symbols == 1) |
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return r->simple_symbols[0]; |
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else |
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return r->simple_symbols[bitstream_read_bit(bc)]; |
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} else |
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return webp_get_vlc(bc, r->vlc.table); |
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} |
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|
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static int huff_reader_build_canonical(HuffReader *r, int *code_lengths, |
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int alphabet_size) |
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{ |
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int len = 0, sym, code = 0, ret; |
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int max_code_length = 0; |
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uint16_t *codes; |
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|
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/* special-case 1 symbol since the vlc reader cannot handle it */ |
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for (sym = 0; sym < alphabet_size; sym++) { |
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if (code_lengths[sym] > 0) { |
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len++; |
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code = sym; |
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if (len > 1) |
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break; |
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} |
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} |
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if (len == 1) { |
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r->nb_symbols = 1; |
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r->simple_symbols[0] = code; |
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r->simple = 1; |
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return 0; |
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} |
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|
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for (sym = 0; sym < alphabet_size; sym++) |
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max_code_length = FFMAX(max_code_length, code_lengths[sym]); |
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|
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if (max_code_length == 0 || max_code_length > MAX_HUFFMAN_CODE_LENGTH) |
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return AVERROR(EINVAL); |
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|
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codes = av_malloc(alphabet_size * sizeof(*codes)); |
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if (!codes) |
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return AVERROR(ENOMEM); |
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|
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code = 0; |
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r->nb_symbols = 0; |
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for (len = 1; len <= max_code_length; len++) { |
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for (sym = 0; sym < alphabet_size; sym++) { |
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if (code_lengths[sym] != len) |
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continue; |
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codes[sym] = code++; |
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r->nb_symbols++; |
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} |
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code <<= 1; |
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} |
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if (!r->nb_symbols) { |
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av_free(codes); |
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return AVERROR_INVALIDDATA; |
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} |
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|
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ret = init_vlc(&r->vlc, 8, alphabet_size, |
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code_lengths, sizeof(*code_lengths), sizeof(*code_lengths), |
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codes, sizeof(*codes), sizeof(*codes), 0); |
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if (ret < 0) { |
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av_free(codes); |
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return ret; |
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} |
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r->simple = 0; |
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|
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av_free(codes); |
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return 0; |
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} |
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|
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static void read_huffman_code_simple(WebPContext *s, HuffReader *hc) |
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{ |
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hc->nb_symbols = bitstream_read_bit(&s->bc) + 1; |
|
|
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if (bitstream_read_bit(&s->bc)) |
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hc->simple_symbols[0] = bitstream_read(&s->bc, 8); |
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else |
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hc->simple_symbols[0] = bitstream_read_bit(&s->bc); |
|
|
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if (hc->nb_symbols == 2) |
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hc->simple_symbols[1] = bitstream_read(&s->bc, 8); |
|
|
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hc->simple = 1; |
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} |
|
|
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static int read_huffman_code_normal(WebPContext *s, HuffReader *hc, |
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int alphabet_size) |
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{ |
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HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } }; |
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int *code_lengths = NULL; |
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int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 }; |
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int i, symbol, max_symbol, prev_code_len, ret; |
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int num_codes = 4 + bitstream_read(&s->bc, 4); |
|
|
|
if (num_codes > NUM_CODE_LENGTH_CODES) |
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return AVERROR_INVALIDDATA; |
|
|
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for (i = 0; i < num_codes; i++) |
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code_length_code_lengths[code_length_code_order[i]] = bitstream_read(&s->bc, 3); |
|
|
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ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths, |
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NUM_CODE_LENGTH_CODES); |
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if (ret < 0) |
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goto finish; |
|
|
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code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths)); |
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if (!code_lengths) { |
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ret = AVERROR(ENOMEM); |
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goto finish; |
|
} |
|
|
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if (bitstream_read_bit(&s->bc)) { |
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int bits = 2 + 2 * bitstream_read(&s->bc, 3); |
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max_symbol = 2 + bitstream_read(&s->bc, bits); |
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if (max_symbol > alphabet_size) { |
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av_log(s->avctx, AV_LOG_ERROR, "max symbol %d > alphabet size %d\n", |
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max_symbol, alphabet_size); |
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ret = AVERROR_INVALIDDATA; |
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goto finish; |
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} |
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} else { |
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max_symbol = alphabet_size; |
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} |
|
|
|
prev_code_len = 8; |
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symbol = 0; |
|
while (symbol < alphabet_size) { |
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int code_len; |
|
|
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if (!max_symbol--) |
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break; |
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code_len = huff_reader_get_symbol(&code_len_hc, &s->bc); |
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if (code_len < 16) { |
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/* Code length code [0..15] indicates literal code lengths. */ |
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code_lengths[symbol++] = code_len; |
|
if (code_len) |
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prev_code_len = code_len; |
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} else { |
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int repeat = 0, length = 0; |
|
switch (code_len) { |
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case 16: |
|
/* Code 16 repeats the previous non-zero value [3..6] times, |
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* i.e., 3 + ReadBits(2) times. If code 16 is used before a |
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* non-zero value has been emitted, a value of 8 is repeated. */ |
|
repeat = 3 + bitstream_read(&s->bc, 2); |
|
length = prev_code_len; |
|
break; |
|
case 17: |
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/* Code 17 emits a streak of zeros [3..10], i.e., |
|
* 3 + ReadBits(3) times. */ |
|
repeat = 3 + bitstream_read(&s->bc, 3); |
|
break; |
|
case 18: |
|
/* Code 18 emits a streak of zeros of length [11..138], i.e., |
|
* 11 + ReadBits(7) times. */ |
|
repeat = 11 + bitstream_read(&s->bc, 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 = bitstream_read(&s->bc, 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 = bitstream_read(&s->bc, 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 (bitstream_read_bit(&s->bc)) { |
|
img->color_cache_bits = bitstream_read(&s->bc, 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 && bitstream_read_bit(&s->bc)) { |
|
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 (bitstream_read_bit(&s->bc)) { |
|
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->bc); |
|
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->bc); |
|
p[3] = huff_reader_get_symbol(&hg[HUFF_IDX_BLUE], &s->bc); |
|
p[0] = huff_reader_get_symbol(&hg[HUFF_IDX_ALPHA], &s->bc); |
|
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 + bitstream_read(&s->bc, extra_bits) + 1; |
|
} |
|
prefix_code = huff_reader_get_symbol(&hg[HUFF_IDX_DIST], &s->bc); |
|
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 + bitstream_read(&s->bc, 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, *pi; |
|
|
|
img = &s->image[IMAGE_ROLE_ARGB]; |
|
pal = &s->image[IMAGE_ROLE_COLOR_INDEXING]; |
|
|
|
if (pal->size_reduction > 0) { |
|
BitstreamContext bc_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]); |
|
bitstream_init8(&bc_g, line, img->frame->linesize[0]); |
|
bitstream_skip(&bc_g, 16); |
|
i = 0; |
|
for (x = 0; x < img->frame->width; x++) { |
|
p = GET_PIXEL(img->frame, x, y); |
|
p[2] = bitstream_read(&bc_g, pixel_bits); |
|
i++; |
|
if (i == 1 << pal->size_reduction) { |
|
bitstream_skip(&bc_g, 24); |
|
i = 0; |
|
} |
|
} |
|
} |
|
av_free(line); |
|
} |
|
|
|
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_log(s->avctx, AV_LOG_ERROR, "invalid palette index %d\n", i); |
|
return AVERROR_INVALIDDATA; |
|
} |
|
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 = bitstream_init8(&s->bc, data_start, data_size); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (!is_alpha_chunk) { |
|
if (bitstream_read(&s->bc, 8) != 0x2F) { |
|
av_log(avctx, AV_LOG_ERROR, "Invalid WebP Lossless signature\n"); |
|
return AVERROR_INVALIDDATA; |
|
} |
|
|
|
w = bitstream_read(&s->bc, 14) + 1; |
|
h = bitstream_read(&s->bc, 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 = bitstream_read_bit(&s->bc); |
|
|
|
if (bitstream_read(&s->bc, 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 (bitstream_read_bit(&s->bc)) { |
|
enum TransformType transform = bitstream_read(&s->bc, 2); |
|
s->transforms[s->nb_transforms++] = transform; |
|
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); |
|
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; |
|
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; |
|
} |
|
|
|
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; |
|
} |
|
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('I', 'C', 'C', 'P'): |
|
case MKTAG('A', 'N', 'I', 'M'): |
|
case MKTAG('A', 'N', 'M', 'F'): |
|
case MKTAG('E', 'X', 'I', '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, |
|
};
|
|
|