| // 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. |
| // ----------------------------------------------------------------------------- |
| // |
| // Color Cache for WebP Lossless |
| // |
| // Authors: Jyrki Alakuijala (jyrki@google.com) |
| // Urvang Joshi (urvang@google.com) |
| |
| #ifndef WEBP_UTILS_COLOR_CACHE_UTILS_H_ |
| #define WEBP_UTILS_COLOR_CACHE_UTILS_H_ |
| |
| #if defined(STARBOARD) |
| #include "starboard/common/log.h" |
| #else |
| #include <assert.h> |
| #endif |
| |
| #include "src/webp/types.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| // Main color cache struct. |
| typedef struct { |
| uint32_t *colors_; // color entries |
| int hash_shift_; // Hash shift: 32 - hash_bits_. |
| int hash_bits_; |
| } VP8LColorCache; |
| |
| static const uint64_t kHashMul = 0x1e35a7bdull; |
| |
| static WEBP_INLINE int VP8LHashPix(uint32_t argb, int shift) { |
| return (int)(((argb * kHashMul) & 0xffffffffu) >> shift); |
| } |
| |
| static WEBP_INLINE uint32_t VP8LColorCacheLookup( |
| const VP8LColorCache* const cc, uint32_t key) { |
| SB_DCHECK((key >> cc->hash_bits_) == 0u); |
| return cc->colors_[key]; |
| } |
| |
| static WEBP_INLINE void VP8LColorCacheSet(const VP8LColorCache* const cc, |
| uint32_t key, uint32_t argb) { |
| SB_DCHECK((key >> cc->hash_bits_) == 0u); |
| cc->colors_[key] = argb; |
| } |
| |
| static WEBP_INLINE void VP8LColorCacheInsert(const VP8LColorCache* const cc, |
| uint32_t argb) { |
| const int key = VP8LHashPix(argb, cc->hash_shift_); |
| cc->colors_[key] = argb; |
| } |
| |
| static WEBP_INLINE int VP8LColorCacheGetIndex(const VP8LColorCache* const cc, |
| uint32_t argb) { |
| return VP8LHashPix(argb, cc->hash_shift_); |
| } |
| |
| // Return the key if cc contains argb, and -1 otherwise. |
| static WEBP_INLINE int VP8LColorCacheContains(const VP8LColorCache* const cc, |
| uint32_t argb) { |
| const int key = VP8LHashPix(argb, cc->hash_shift_); |
| return (cc->colors_[key] == argb) ? key : -1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| |
| // Initializes the color cache with 'hash_bits' bits for the keys. |
| // Returns false in case of memory error. |
| int VP8LColorCacheInit(VP8LColorCache* const color_cache, int hash_bits); |
| |
| void VP8LColorCacheCopy(const VP8LColorCache* const src, |
| VP8LColorCache* const dst); |
| |
| // Delete the memory associated to color cache. |
| void VP8LColorCacheClear(VP8LColorCache* const color_cache); |
| |
| //------------------------------------------------------------------------------ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif // WEBP_UTILS_COLOR_CACHE_UTILS_H_ |