vp8li_enc.h - mozsearch

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// 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 encoder: internal header.

//

// Author: Vikas Arora (vikaas.arora@gmail.com)

#ifndef WEBP_ENC_VP8LI_ENC_H_

#define WEBP_ENC_VP8LI_ENC_H_

#ifdef HAVE_CONFIG_H

#include "src/webp/config.h"

#endif

#include <stddef.h>

// Either WEBP_NEAR_LOSSLESS is defined as 0 in config.h when compiling to

// disable near-lossless, or it is enabled by default.

#ifndef WEBP_NEAR_LOSSLESS

#define WEBP_NEAR_LOSSLESS 1

#endif

#include "src/webp/types.h"

#include "src/enc/backward_references_enc.h"

#include "src/enc/histogram_enc.h"

#include "src/utils/bit_writer_utils.h"

#include "src/webp/encode.h"

#include "src/webp/format_constants.h"

#ifdef __cplusplus

extern "C" {

#endif

// maximum value of 'transform_bits' in VP8LEncoder.

#define MAX_TRANSFORM_BITS (MIN_TRANSFORM_BITS + (1 << NUM_TRANSFORM_BITS) - 1)

typedef enum {

  kEncoderNone = 0,

  kEncoderARGB,

  kEncoderNearLossless,

  kEncoderPalette

} VP8LEncoderARGBContent;

typedef struct {

  const WebPConfig* config;      // user configuration and parameters

  const WebPPicture* pic;        // input picture.

  uint32_t* argb;                       // Transformed argb image data.

  VP8LEncoderARGBContent argb_content;  // Content type of the argb buffer.

  uint32_t* argb_scratch;               // Scratch memory for argb rows

                                        // (used for prediction).

  uint32_t* transform_data;             // Scratch memory for transform data.

  uint32_t* transform_mem;              // Currently allocated memory.

  size_t    transform_mem_size;         // Currently allocated memory size.

  int       current_width;       // Corresponds to packed image width.

  // Encoding parameters derived from quality parameter.

  int histo_bits;

  int predictor_transform_bits;    // <= MAX_TRANSFORM_BITS

  int cross_color_transform_bits;  // <= MAX_TRANSFORM_BITS

  int cache_bits;        // If equal to 0, don't use color cache.

  // Encoding parameters derived from image characteristics.

  int use_cross_color;

  int use_subtract_green;

  int use_predict;

  int use_palette;

  int palette_size;

  uint32_t palette[MAX_PALETTE_SIZE];

  // Sorted version of palette for cache purposes.

  uint32_t palette_sorted[MAX_PALETTE_SIZE];

  // Some 'scratch' (potentially large) objects.

  struct VP8LBackwardRefs refs[4];  // Backward Refs array for temporaries.

  VP8LHashChain hash_chain;         // HashChain data for constructing

                                    // backward references.

} VP8LEncoder;

//------------------------------------------------------------------------------

// internal functions. Not public.

// Encodes the picture.

// Returns 0 if config or picture is NULL or picture doesn't have valid argb

// input.

int VP8LEncodeImage(const WebPConfig* const config,

                    const WebPPicture* const picture);

// Encodes the main image stream using the supplied bit writer.

// Returns false in case of error (stored in picture->error_code).

int VP8LEncodeStream(const WebPConfig* const config,

                     const WebPPicture* const picture, VP8LBitWriter* const bw);

#if (WEBP_NEAR_LOSSLESS == 1)

// in near_lossless.c

// Near lossless preprocessing in RGB color-space.

int VP8ApplyNearLossless(const WebPPicture* const picture, int quality,

                         uint32_t* const argb_dst);

#endif

//------------------------------------------------------------------------------

// Image transforms in predictor.c.

// pic and percent are for progress.

// Returns false in case of error (stored in pic->error_code).

int VP8LResidualImage(int width, int height, int min_bits, int max_bits,

                      int low_effort, uint32_t* const argb,

                      uint32_t* const argb_scratch, uint32_t* const image,

                      int near_lossless, int exact, int used_subtract_green,

                      const WebPPicture* const pic, int percent_range,

                      int* const percent, int* const best_bits);

int VP8LColorSpaceTransform(int width, int height, int bits, int quality,

                            uint32_t* const argb, uint32_t* image,

                            const WebPPicture* const pic, int percent_range,

                            int* const percent, int* const best_bits);

void VP8LOptimizeSampling(uint32_t* const image, int full_width,

                          int full_height, int bits, int max_bits,

                          int* best_bits_out);

//------------------------------------------------------------------------------

#ifdef __cplusplus

}    // extern "C"

#endif

#endif  // WEBP_ENC_VP8LI_ENC_H_