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)
18extern "C" {
19#endif
20
21extern const uint16_t VP8LevelFixedCosts[2048];   // approximate cost per level
22extern const uint16_t VP8EntropyCost[256];        // 8bit fixed-point log(p)
23
24// Cost of coding one event with probability 'proba'.
25static 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.
30static inline uint64_t VP8BranchCost(uint64_t nb, uint64_t total, uint8_t proba) {
31  return nb * VP8BitCost(1, proba) + (total - nb) * VP8BitCost(0, proba);
32}
33
34// Level cost calculations
35void VP8CalculateLevelCosts(VP8Proba* const proba);
36static inline int VP8LevelCost(const uint16_t* const table, int level) {
37  return VP8LevelFixedCosts[level]
38       + table[level > MAX_VARIABLE_LEVEL ? MAX_VARIABLE_LEVEL : level];
39}
40
41// Mode costs
42extern const uint16_t VP8FixedCostsUV[4];
43extern const uint16_t VP8FixedCostsI16[4];
44extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
45
46//-----------------------------------------------------------------------------
47
48#if defined(__cplusplus) || defined(c_plusplus)
49}    // extern "C"
50#endif
51
52#endif  // WEBP_ENC_COST_H_
53