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1 // Copyright 2011 Google Inc.
2 //
3 // This code is licensed under the same terms as WebM:
4 //  Software License Agreement:  http://www.webmproject.org/license/software/
5 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
6 // -----------------------------------------------------------------------------
7 //
8 // Cost tables for level and modes.
9 //
10 // Author: Skal (pascal.massimino@gmail.com)
11 
12 #ifndef WEBP_ENC_COST_H_
13 #define WEBP_ENC_COST_H_
14 
15 #include "vp8enci.h"
16 
17 #if defined(__cplusplus) || defined(c_plusplus)
18 extern "C" {
19 #endif
20 
21 extern const uint16_t VP8LevelFixedCosts[2048];   // approximate cost per level
22 extern const uint16_t VP8EntropyCost[256];        // 8bit fixed-point log(p)
23 
24 // Cost of coding one event with probability 'proba'.
VP8BitCost(int bit,uint8_t proba)25 static inline int VP8BitCost(int bit, uint8_t proba) {
26   return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
27 }
28 
29 // Cost of coding 'nb' 1's and 'total-nb' 0's using 'proba' probability.
VP8BranchCost(uint64_t nb,uint64_t total,uint8_t proba)30 static inline uint64_t VP8BranchCost(uint64_t nb, uint64_t total,
31                                      uint8_t proba) {
32   return nb * VP8BitCost(1, proba) + (total - nb) * VP8BitCost(0, proba);
33 }
34 
35 // Level cost calculations
36 extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
37 void VP8CalculateLevelCosts(VP8Proba* const proba);
VP8LevelCost(const uint16_t * const table,int level)38 static inline int VP8LevelCost(const uint16_t* const table, int level) {
39   return VP8LevelFixedCosts[level]
40        + table[level > MAX_VARIABLE_LEVEL ? MAX_VARIABLE_LEVEL : level];
41 }
42 
43 // Mode costs
44 extern const uint16_t VP8FixedCostsUV[4];
45 extern const uint16_t VP8FixedCostsI16[4];
46 extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
47 
48 //-----------------------------------------------------------------------------
49 
50 #if defined(__cplusplus) || defined(c_plusplus)
51 }    // extern "C"
52 #endif
53 
54 #endif  // WEBP_ENC_COST_H_
55