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 <assert.h>
  18 #include <stdlib.h>
  19 #include "./vp8enci.h"
  20
  21 #ifdef __cplusplus
  22 extern "C" {
  23 #endif
  24
  25 // On-the-fly info about the current set of residuals. Handy to avoid
  26 // passing zillions of params.
  27 typedef struct {
  28   int first;
  29   int last;
  30   const int16_t* coeffs;
  31
  32   int coeff_type;
  33   ProbaArray* prob;
  34   StatsArray* stats;
  35   CostArray*  cost;
  36 } VP8Residual;
  37
  38 void VP8InitResidual(int first, int coeff_type,
  39                      VP8Encoder* const enc, VP8Residual* const res);
  40
  41 typedef void (*VP8SetResidualCoeffsFunc)(const int16_t* const coeffs,
  42                                          VP8Residual* const res);
  43 extern VP8SetResidualCoeffsFunc VP8SetResidualCoeffs;
  44
  45 void VP8SetResidualCoeffsInit(void);  // must be called first
  46
  47 int VP8RecordCoeffs(int ctx, const VP8Residual* const res);
  48
  49 // approximate cost per level:
  50 extern const uint16_t VP8LevelFixedCosts[MAX_LEVEL + 1];
  51 extern const uint16_t VP8EntropyCost[256];        // 8bit fixed-point log(p)
  52
  53 // Cost of coding one event with probability 'proba'.
  54 static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) {
  55   return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
  56 }
  57
  58 // Cost calculation function.
  59 typedef int (*VP8GetResidualCostFunc)(int ctx0, const VP8Residual* const res);
  60 extern VP8GetResidualCostFunc VP8GetResidualCost;
  61
  62 void VP8GetResidualCostInit(void);  // must be called first
  63
  64 // Level cost calculations
  65 extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
  66 void VP8CalculateLevelCosts(VP8Proba* const proba);
  67 static WEBP_INLINE int VP8LevelCost(const uint16_t* const table, int level) {
  68   return VP8LevelFixedCosts[level]
  69        + table[(level > MAX_VARIABLE_LEVEL) ? MAX_VARIABLE_LEVEL : level];
  70 }
  71
  72 // Mode costs
  73 extern const uint16_t VP8FixedCostsUV[4];
  74 extern const uint16_t VP8FixedCostsI16[4];
  75 extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
  76
  77 //------------------------------------------------------------------------------
  78
  79 #ifdef __cplusplus
  80 }    // extern "C"
  81 #endif
  82
  83 #endif  /* WEBP_ENC_COST_H_ */