| // Copyright 2012 Google Inc. All Rights Reserved. |
| // |
| // Use of this source code is governed by a BSD-style license |
| // that can be found in the COPYING file in the root of the source |
| // tree. An additional intellectual property rights grant can be found |
| // in the file PATENTS. All contributing project authors may |
| // be found in the AUTHORS file in the root of the source tree. |
| // ----------------------------------------------------------------------------- |
| // |
| // Lossless decoder: internal header. |
| // |
| // Author: Skal (pascal.massimino@gmail.com) |
| // Vikas Arora(vikaas.arora@gmail.com) |
| |
| #ifndef WEBP_DEC_VP8LI_H_ |
| #define WEBP_DEC_VP8LI_H_ |
| |
| #if defined(STARBOARD) |
| #include "starboard/memory.h" |
| #else |
| #include <string.h> // for memcpy() |
| #endif |
| |
| #include "./webpi.h" |
| #include "../utils/bit_reader.h" |
| #include "../utils/color_cache.h" |
| #include "../utils/huffman.h" |
| #include "../webp/format_constants.h" |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| extern "C" { |
| #endif |
| |
| typedef enum { |
| READ_DATA = 0, |
| READ_HDR = 1, |
| READ_DIM = 2 |
| } VP8LDecodeState; |
| |
| typedef struct VP8LTransform VP8LTransform; |
| struct VP8LTransform { |
| VP8LImageTransformType type_; // transform type. |
| int bits_; // subsampling bits defining transform window. |
| int xsize_; // transform window X index. |
| int ysize_; // transform window Y index. |
| uint32_t *data_; // transform data. |
| }; |
| |
| typedef struct { |
| HuffmanTree htrees_[HUFFMAN_CODES_PER_META_CODE]; |
| } HTreeGroup; |
| |
| typedef struct { |
| int color_cache_size_; |
| VP8LColorCache color_cache_; |
| |
| int huffman_mask_; |
| int huffman_subsample_bits_; |
| int huffman_xsize_; |
| uint32_t *huffman_image_; |
| int num_htree_groups_; |
| HTreeGroup *htree_groups_; |
| } VP8LMetadata; |
| |
| typedef struct { |
| VP8StatusCode status_; |
| VP8LDecodeState action_; |
| VP8LDecodeState state_; |
| VP8Io *io_; |
| |
| const WebPDecBuffer *output_; // shortcut to io->opaque->output |
| |
| uint32_t *pixels_; // Internal data: either uint8_t* for alpha |
| // or uint32_t* for BGRA. |
| uint32_t *argb_cache_; // Scratch buffer for temporary BGRA storage. |
| |
| VP8LBitReader br_; |
| |
| int width_; |
| int height_; |
| int last_row_; // last input row decoded so far. |
| int last_out_row_; // last row output so far. |
| |
| VP8LMetadata hdr_; |
| |
| int next_transform_; |
| VP8LTransform transforms_[NUM_TRANSFORMS]; |
| // or'd bitset storing the transforms types. |
| uint32_t transforms_seen_; |
| |
| uint8_t *rescaler_memory; // Working memory for rescaling work. |
| WebPRescaler *rescaler; // Common rescaler for all channels. |
| } VP8LDecoder; |
| |
| //------------------------------------------------------------------------------ |
| // internal functions. Not public. |
| |
| // in vp8l.c |
| |
| // Decodes a raw image stream (without header) and store the alpha data |
| // into *output, which must be of size width x height. Returns false in case |
| // of error. |
| int VP8LDecodeAlphaImageStream(int width, int height, const uint8_t* const data, |
| size_t data_size, uint8_t* const output); |
| |
| // Allocates and initialize a new lossless decoder instance. |
| VP8LDecoder* VP8LNew(void); |
| |
| // Decodes the image header. Returns false in case of error. |
| int VP8LDecodeHeader(VP8LDecoder* const dec, VP8Io* const io); |
| |
| // Decodes an image. It's required to decode the lossless header before calling |
| // this function. Returns false in case of error, with updated dec->status_. |
| int VP8LDecodeImage(VP8LDecoder* const dec); |
| |
| // Resets the decoder in its initial state, reclaiming memory. |
| // Preserves the dec->status_ value. |
| void VP8LClear(VP8LDecoder* const dec); |
| |
| // Clears and deallocate a lossless decoder instance. |
| void VP8LDelete(VP8LDecoder* const dec); |
| |
| //------------------------------------------------------------------------------ |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| } // extern "C" |
| #endif |
| |
| #endif /* WEBP_DEC_VP8LI_H_ */ |