1 // Copyright 2012 Google Inc. All Rights Reserved. 2 // 3 // Use of this source code is governed by a BSD-style license 4 // that can be found in the COPYING file in the root of the source 5 // tree. An additional intellectual property rights grant can be found 6 // in the file PATENTS. All contributing project authors may 7 // be found in the AUTHORS file in the root of the source tree. 8 // ----------------------------------------------------------------------------- 9 // 10 // Lossless encoder: internal header. 11 // 12 // Author: Vikas Arora (vikaas.arora@gmail.com) 13 14 #ifndef WEBP_ENC_VP8LI_ENC_H_ 15 #define WEBP_ENC_VP8LI_ENC_H_ 16 17 #ifdef HAVE_CONFIG_H 18 #include "src/webp/config.h" 19 #endif 20 // Either WEBP_NEAR_LOSSLESS is defined as 0 in config.h when compiling to 21 // disable near-lossless, or it is enabled by default. 22 #ifndef WEBP_NEAR_LOSSLESS 23 #define WEBP_NEAR_LOSSLESS 1 24 #endif 25 26 #include "src/enc/backward_references_enc.h" 27 #include "src/enc/histogram_enc.h" 28 #include "src/utils/bit_writer_utils.h" 29 #include "src/webp/encode.h" 30 #include "src/webp/format_constants.h" 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 // maximum value of transform_bits_ in VP8LEncoder. 37 #define MAX_TRANSFORM_BITS (MIN_TRANSFORM_BITS + (1 << NUM_TRANSFORM_BITS) - 1) 38 39 typedef enum { 40 kEncoderNone = 0, 41 kEncoderARGB, 42 kEncoderNearLossless, 43 kEncoderPalette 44 } VP8LEncoderARGBContent; 45 46 typedef struct { 47 const WebPConfig* config_; // user configuration and parameters 48 const WebPPicture* pic_; // input picture. 49 50 uint32_t* argb_; // Transformed argb image data. 51 VP8LEncoderARGBContent argb_content_; // Content type of the argb buffer. 52 uint32_t* argb_scratch_; // Scratch memory for argb rows 53 // (used for prediction). 54 uint32_t* transform_data_; // Scratch memory for transform data. 55 uint32_t* transform_mem_; // Currently allocated memory. 56 size_t transform_mem_size_; // Currently allocated memory size. 57 58 int current_width_; // Corresponds to packed image width. 59 60 // Encoding parameters derived from quality parameter. 61 int histo_bits_; 62 int predictor_transform_bits_; // <= MAX_TRANSFORM_BITS 63 int cross_color_transform_bits_; // <= MAX_TRANSFORM_BITS 64 int cache_bits_; // If equal to 0, don't use color cache. 65 66 // Encoding parameters derived from image characteristics. 67 int use_cross_color_; 68 int use_subtract_green_; 69 int use_predict_; 70 int use_palette_; 71 int palette_size_; 72 uint32_t palette_[MAX_PALETTE_SIZE]; 73 // Sorted version of palette_ for cache purposes. 74 uint32_t palette_sorted_[MAX_PALETTE_SIZE]; 75 76 // Some 'scratch' (potentially large) objects. 77 struct VP8LBackwardRefs refs_[4]; // Backward Refs array for temporaries. 78 VP8LHashChain hash_chain_; // HashChain data for constructing 79 // backward references. 80 } VP8LEncoder; 81 82 //------------------------------------------------------------------------------ 83 // internal functions. Not public. 84 85 // Encodes the picture. 86 // Returns 0 if config or picture is NULL or picture doesn't have valid argb 87 // input. 88 int VP8LEncodeImage(const WebPConfig* const config, 89 const WebPPicture* const picture); 90 91 // Encodes the main image stream using the supplied bit writer. 92 // Returns false in case of error (stored in picture->error_code). 93 int VP8LEncodeStream(const WebPConfig* const config, 94 const WebPPicture* const picture, VP8LBitWriter* const bw); 95 96 #if (WEBP_NEAR_LOSSLESS == 1) 97 // in near_lossless.c 98 // Near lossless preprocessing in RGB color-space. 99 int VP8ApplyNearLossless(const WebPPicture* const picture, int quality, 100 uint32_t* const argb_dst); 101 #endif 102 103 //------------------------------------------------------------------------------ 104 // Image transforms in predictor.c. 105 106 // pic and percent are for progress. 107 // Returns false in case of error (stored in pic->error_code). 108 int VP8LResidualImage(int width, int height, int min_bits, int max_bits, 109 int low_effort, uint32_t* const argb, 110 uint32_t* const argb_scratch, uint32_t* const image, 111 int near_lossless, int exact, int used_subtract_green, 112 const WebPPicture* const pic, int percent_range, 113 int* const percent, int* const best_bits); 114 115 int VP8LColorSpaceTransform(int width, int height, int bits, int quality, 116 uint32_t* const argb, uint32_t* image, 117 const WebPPicture* const pic, int percent_range, 118 int* const percent, int* const best_bits); 119 120 void VP8LOptimizeSampling(uint32_t* const image, int full_width, 121 int full_height, int bits, int max_bits, 122 int* best_bits_out); 123 124 //------------------------------------------------------------------------------ 125 126 #ifdef __cplusplus 127 } // extern "C" 128 #endif 129 130 #endif // WEBP_ENC_VP8LI_ENC_H_ 131