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 6 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 transform_bits_; // <= MAX_TRANSFORM_BITS. 63 int cache_bits_; // If equal to 0, don't use color cache. 64 65 // Encoding parameters derived from image characteristics. 66 int use_cross_color_; 67 int use_subtract_green_; 68 int use_predict_; 69 int use_palette_; 70 int palette_size_; 71 uint32_t palette_[MAX_PALETTE_SIZE]; 72 73 // Some 'scratch' (potentially large) objects. 74 struct VP8LBackwardRefs refs_[3]; // Backward Refs array for temporaries. 75 VP8LHashChain hash_chain_; // HashChain data for constructing 76 // backward references. 77 } VP8LEncoder; 78 79 //------------------------------------------------------------------------------ 80 // internal functions. Not public. 81 82 // Encodes the picture. 83 // Returns 0 if config or picture is NULL or picture doesn't have valid argb 84 // input. 85 int VP8LEncodeImage(const WebPConfig* const config, 86 const WebPPicture* const picture); 87 88 // Encodes the main image stream using the supplied bit writer. 89 // If 'use_cache' is false, disables the use of color cache. 90 WebPEncodingError VP8LEncodeStream(const WebPConfig* const config, 91 const WebPPicture* const picture, 92 VP8LBitWriter* const bw, int use_cache); 93 94 #if (WEBP_NEAR_LOSSLESS == 1) 95 // in near_lossless.c 96 // Near lossless preprocessing in RGB color-space. 97 int VP8ApplyNearLossless(const WebPPicture* const picture, int quality, 98 uint32_t* const argb_dst); 99 #endif 100 101 //------------------------------------------------------------------------------ 102 // Image transforms in predictor.c. 103 104 void VP8LResidualImage(int width, int height, int bits, int low_effort, 105 uint32_t* const argb, uint32_t* const argb_scratch, 106 uint32_t* const image, int near_lossless, int exact, 107 int used_subtract_green); 108 109 void VP8LColorSpaceTransform(int width, int height, int bits, int quality, 110 uint32_t* const argb, uint32_t* image); 111 112 //------------------------------------------------------------------------------ 113 114 #ifdef __cplusplus 115 } // extern "C" 116 #endif 117 118 #endif // WEBP_ENC_VP8LI_ENC_H_ 119