1a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Copyright 2012 Google Inc. All Rights Reserved. 2a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// 30406ce1417f76f2034833414dcecc9f56253640cVikas Arora// Use of this source code is governed by a BSD-style license 40406ce1417f76f2034833414dcecc9f56253640cVikas Arora// that can be found in the COPYING file in the root of the source 50406ce1417f76f2034833414dcecc9f56253640cVikas Arora// tree. An additional intellectual property rights grant can be found 60406ce1417f76f2034833414dcecc9f56253640cVikas Arora// in the file PATENTS. All contributing project authors may 70406ce1417f76f2034833414dcecc9f56253640cVikas Arora// be found in the AUTHORS file in the root of the source tree. 8a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// ----------------------------------------------------------------------------- 9a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// 10a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Author: Jyrki Alakuijala (jyrki@google.com) 11a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// 12a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 13a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#ifndef WEBP_ENC_BACKWARD_REFERENCES_H_ 14a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#define WEBP_ENC_BACKWARD_REFERENCES_H_ 15a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 16a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#include <assert.h> 17a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#include <stdlib.h> 18e8a1b86cc3afe4791ab40d89240c40797a400131James Zern#include "../webp/types.h" 19e8a1b86cc3afe4791ab40d89240c40797a400131James Zern#include "../webp/format_constants.h" 20a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 218b720228d581a84fd173b6dcb2fa295b59db489aVikas Arora#ifdef __cplusplus 22a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroraextern "C" { 23a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif 24a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 257c8da7ce66017295a65ec028084b90800be377f8James Zern// The maximum allowed limit is 11. 267c8da7ce66017295a65ec028084b90800be377f8James Zern#define MAX_COLOR_CACHE_BITS 10 27a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 28a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// ----------------------------------------------------------------------------- 29a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// PixOrCopy 30a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 31a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroraenum Mode { 32a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora kLiteral, 33a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora kCacheIdx, 34a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora kCopy, 35a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora kNone 36a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora}; 37a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 38a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroratypedef struct { 39a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora // mode as uint8_t to make the memory layout to be exactly 8 bytes. 40a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora uint8_t mode; 41a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora uint16_t len; 42a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora uint32_t argb_or_distance; 43a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} PixOrCopy; 44a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 45a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE PixOrCopy PixOrCopyCreateCopy(uint32_t distance, 46a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora uint16_t len) { 47a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora PixOrCopy retval; 48a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.mode = kCopy; 49a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.argb_or_distance = distance; 50a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.len = len; 51a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return retval; 52a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 53a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 54a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE PixOrCopy PixOrCopyCreateCacheIdx(int idx) { 55a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora PixOrCopy retval; 56a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(idx >= 0); 57a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(idx < (1 << MAX_COLOR_CACHE_BITS)); 58a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.mode = kCacheIdx; 59a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.argb_or_distance = idx; 60a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.len = 1; 61a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return retval; 62a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 63a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 64a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE PixOrCopy PixOrCopyCreateLiteral(uint32_t argb) { 65a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora PixOrCopy retval; 66a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.mode = kLiteral; 67a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.argb_or_distance = argb; 68a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora retval.len = 1; 69a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return retval; 70a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 71a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 72a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE int PixOrCopyIsLiteral(const PixOrCopy* const p) { 73a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return (p->mode == kLiteral); 74a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 75a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 76a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE int PixOrCopyIsCacheIdx(const PixOrCopy* const p) { 77a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return (p->mode == kCacheIdx); 78a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 79a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 80a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE int PixOrCopyIsCopy(const PixOrCopy* const p) { 81a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return (p->mode == kCopy); 82a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 83a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 84a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE uint32_t PixOrCopyLiteral(const PixOrCopy* const p, 85a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora int component) { 86a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(p->mode == kLiteral); 87a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return (p->argb_or_distance >> (component * 8)) & 0xff; 88a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 89a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 90a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE uint32_t PixOrCopyLength(const PixOrCopy* const p) { 91a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return p->len; 92a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 93a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 94a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE uint32_t PixOrCopyArgb(const PixOrCopy* const p) { 95a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(p->mode == kLiteral); 96a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return p->argb_or_distance; 97a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 98a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 99a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE uint32_t PixOrCopyCacheIdx(const PixOrCopy* const p) { 100a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(p->mode == kCacheIdx); 101a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(p->argb_or_distance < (1U << MAX_COLOR_CACHE_BITS)); 102a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return p->argb_or_distance; 103a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 104a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 105a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arorastatic WEBP_INLINE uint32_t PixOrCopyDistance(const PixOrCopy* const p) { 106a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora assert(p->mode == kCopy); 107a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora return p->argb_or_distance; 108a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 109a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 110a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// ----------------------------------------------------------------------------- 11133f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// VP8LHashChain 11233f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 11333f74dabbc7920a65ed435d7417987589febdc16Vikas Arora#define HASH_BITS 18 11433f74dabbc7920a65ed435d7417987589febdc16Vikas Arora#define HASH_SIZE (1 << HASH_BITS) 11533f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 11633f74dabbc7920a65ed435d7417987589febdc16Vikas Aroratypedef struct VP8LHashChain VP8LHashChain; 11733f74dabbc7920a65ed435d7417987589febdc16Vikas Arorastruct VP8LHashChain { 1180912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern // The 20 most significant bits contain the offset at which the best match 1190912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern // is found. These 20 bits are the limit defined by GetWindowSizeForHashChain 1200912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern // (through WINDOW_SIZE = 1<<20). 1210912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern // The lower 12 bits contain the length of the match. The 12 bit limit is 1220912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern // defined in MaxFindCopyLength with MAX_LENGTH=4096. 1230912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern uint32_t* offset_length_; 12433f74dabbc7920a65ed435d7417987589febdc16Vikas Arora // This is the maximum size of the hash_chain that can be constructed. 12533f74dabbc7920a65ed435d7417987589febdc16Vikas Arora // Typically this is the pixel count (width x height) for a given image. 12633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora int size_; 12733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora}; 128a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 12933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Must be called first, to set size. 13033f74dabbc7920a65ed435d7417987589febdc16Vikas Aroraint VP8LHashChainInit(VP8LHashChain* const p, int size); 1310912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern// Pre-compute the best matches for argb. 1320912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zernint VP8LHashChainFill(VP8LHashChain* const p, int quality, 133fa39824bb690c5806358871f46940d0450973d8aJames Zern const uint32_t* const argb, int xsize, int ysize, 134fa39824bb690c5806358871f46940d0450973d8aJames Zern int low_effort); 13533f74dabbc7920a65ed435d7417987589febdc16Vikas Aroravoid VP8LHashChainClear(VP8LHashChain* const p); // release memory 136a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 13733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// ----------------------------------------------------------------------------- 13833f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// VP8LBackwardRefs (block-based backward-references storage) 13933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 14033f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// maximum number of reference blocks the image will be segmented into 14133f74dabbc7920a65ed435d7417987589febdc16Vikas Arora#define MAX_REFS_BLOCK_PER_IMAGE 16 14233f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 14333f74dabbc7920a65ed435d7417987589febdc16Vikas Aroratypedef struct PixOrCopyBlock PixOrCopyBlock; // forward declaration 14433f74dabbc7920a65ed435d7417987589febdc16Vikas Aroratypedef struct VP8LBackwardRefs VP8LBackwardRefs; 14533f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 14633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Container for blocks chain 14733f74dabbc7920a65ed435d7417987589febdc16Vikas Arorastruct VP8LBackwardRefs { 14833f74dabbc7920a65ed435d7417987589febdc16Vikas Arora int block_size_; // common block-size 14933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora int error_; // set to true if some memory error occurred 15033f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopyBlock* refs_; // list of currently used blocks 15133f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopyBlock** tail_; // for list recycling 15233f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopyBlock* free_blocks_; // free-list 15333f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopyBlock* last_block_; // used for adding new refs (internal) 15433f74dabbc7920a65ed435d7417987589febdc16Vikas Arora}; 155a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 15633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Initialize the object. 'block_size' is the common block size to store 15733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// references (typically, width * height / MAX_REFS_BLOCK_PER_IMAGE). 15833f74dabbc7920a65ed435d7417987589febdc16Vikas Aroravoid VP8LBackwardRefsInit(VP8LBackwardRefs* const refs, int block_size); 15933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Release memory for backward references. 16033f74dabbc7920a65ed435d7417987589febdc16Vikas Aroravoid VP8LBackwardRefsClear(VP8LBackwardRefs* const refs); 16133f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Copies the 'src' backward refs to the 'dst'. Returns 0 in case of error. 16233f74dabbc7920a65ed435d7417987589febdc16Vikas Aroraint VP8LBackwardRefsCopy(const VP8LBackwardRefs* const src, 16333f74dabbc7920a65ed435d7417987589febdc16Vikas Arora VP8LBackwardRefs* const dst); 164a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 16533f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Cursor for iterating on references content 16633f74dabbc7920a65ed435d7417987589febdc16Vikas Aroratypedef struct { 16733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora // public: 16833f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopy* cur_pos; // current position 16933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora // private: 17033f74dabbc7920a65ed435d7417987589febdc16Vikas Arora PixOrCopyBlock* cur_block_; // current block in the refs list 17133f74dabbc7920a65ed435d7417987589febdc16Vikas Arora const PixOrCopy* last_pos_; // sentinel for switching to next block 17233f74dabbc7920a65ed435d7417987589febdc16Vikas Arora} VP8LRefsCursor; 17333f74dabbc7920a65ed435d7417987589febdc16Vikas Arora 17433f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Returns a cursor positioned at the beginning of the references list. 17533f74dabbc7920a65ed435d7417987589febdc16Vikas AroraVP8LRefsCursor VP8LRefsCursorInit(const VP8LBackwardRefs* const refs); 17633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Returns true if cursor is pointing at a valid position. 17733f74dabbc7920a65ed435d7417987589febdc16Vikas Arorastatic WEBP_INLINE int VP8LRefsCursorOk(const VP8LRefsCursor* const c) { 17833f74dabbc7920a65ed435d7417987589febdc16Vikas Arora return (c->cur_pos != NULL); 17933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora} 18033f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Move to next block of references. Internal, not to be called directly. 18133f74dabbc7920a65ed435d7417987589febdc16Vikas Aroravoid VP8LRefsCursorNextBlock(VP8LRefsCursor* const c); 18233f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// Move to next position, or NULL. Should not be called if !VP8LRefsCursorOk(). 18333f74dabbc7920a65ed435d7417987589febdc16Vikas Arorastatic WEBP_INLINE void VP8LRefsCursorNext(VP8LRefsCursor* const c) { 18433f74dabbc7920a65ed435d7417987589febdc16Vikas Arora assert(c != NULL); 18533f74dabbc7920a65ed435d7417987589febdc16Vikas Arora assert(VP8LRefsCursorOk(c)); 18633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora if (++c->cur_pos == c->last_pos_) VP8LRefsCursorNextBlock(c); 18733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora} 188a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 189a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// ----------------------------------------------------------------------------- 190a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Main entry points 191a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 192a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Evaluates best possible backward references for specified quality. 1937c8da7ce66017295a65ec028084b90800be377f8James Zern// The input cache_bits to 'VP8LGetBackwardReferences' sets the maximum cache 1947c8da7ce66017295a65ec028084b90800be377f8James Zern// bits to use (passing 0 implies disabling the local color cache). 1957c8da7ce66017295a65ec028084b90800be377f8James Zern// The optimal cache bits is evaluated and set for the *cache_bits parameter. 19633f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// The return value is the pointer to the best of the two backward refs viz, 19733f74dabbc7920a65ed435d7417987589febdc16Vikas Arora// refs[0] or refs[1]. 19833f74dabbc7920a65ed435d7417987589febdc16Vikas AroraVP8LBackwardRefs* VP8LGetBackwardReferences( 19933f74dabbc7920a65ed435d7417987589febdc16Vikas Arora int width, int height, const uint32_t* const argb, int quality, 2000912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern int low_effort, int* const cache_bits, 2010912efc2528d03c59d45dd9bdc9ff9ec800a3fc1James Zern const VP8LHashChain* const hash_chain, VP8LBackwardRefs refs[2]); 202a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 2038b720228d581a84fd173b6dcb2fa295b59db489aVikas Arora#ifdef __cplusplus 204a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} 205a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif 206a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora 207a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif // WEBP_ENC_BACKWARD_REFERENCES_H_ 208