121 lines
3.8 KiB
C
121 lines
3.8 KiB
C
// Copyright 2012 Google Inc. All Rights Reserved.
|
|
//
|
|
// This code is licensed under the same terms as WebM:
|
|
// Software License Agreement: http://www.webmproject.org/license/software/
|
|
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// 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_
|
|
|
|
#include <string.h> // for memcpy()
|
|
#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 *argb_; // Internal data: always in BGRA color mode.
|
|
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_ */
|