third_party/libwebp/enc/cost.h

   1 // Copyright 2011 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 // Cost tables for level and modes.
  11 //
  12 // Author: Skal (pascal.massimino@gmail.com)
  13
  14 #ifndef WEBP_ENC_COST_H_
  15 #define WEBP_ENC_COST_H_
  16
  17 #include "./vp8enci.h"
  18
  19 #ifdef __cplusplus
  20 extern "C" {
  21 #endif
  22
  23 // approximate cost per level:
  24 extern const uint16_t VP8LevelFixedCosts[MAX_LEVEL + 1];
  25 extern const uint16_t VP8EntropyCost[256];        // 8bit fixed-point log(p)
  26
  27 // Cost of coding one event with probability 'proba'.
  28 static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) {
  29   return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
  30 }
  31
  32 // Level cost calculations
  33 extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
  34 void VP8CalculateLevelCosts(VP8Proba* const proba);
  35 static WEBP_INLINE int VP8LevelCost(const uint16_t* const table, int level) {
  36   return VP8LevelFixedCosts[level]
  37        + table[(level > MAX_VARIABLE_LEVEL) ? MAX_VARIABLE_LEVEL : level];
  38 }
  39
  40 // Mode costs
  41 extern const uint16_t VP8FixedCostsUV[4];
  42 extern const uint16_t VP8FixedCostsI16[4];
  43 extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
  44
  45 //------------------------------------------------------------------------------
  46
  47 #ifdef __cplusplus
  48 }    // extern "C"
  49 #endif
  50
  51 #endif  /* WEBP_ENC_COST_H_ */