text: // 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
  // 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/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 6
  
  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 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];
  
    // 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.
  // If 'use_cache' is false, disables the use of color cache.
  WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
                                     const WebPPicture* const picture,
                                     VP8LBitWriter* const bw, int use_cache);
  
  #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.
  
  void VP8LResidualImage(int width, int height, int 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);
  
  void VP8LColorSpaceTransform(int width, int height, int bits, int quality,
                               uint32_t* const argb, uint32_t* image);
  
  //------------------------------------------------------------------------------
  
  #ifdef __cplusplus
  }    // extern "C"
  #endif
  
  #endif  // WEBP_ENC_VP8LI_ENC_H_
  