Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2011 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.
// -----------------------------------------------------------------------------
//
// Cost tables for level and modes.
//
// Author: Skal (pascal.massimino@gmail.com)
#ifndef WEBP_ENC_COST_ENC_H_
#define WEBP_ENC_COST_ENC_H_
#include <assert.h>
#include <stdlib.h>
#include "src/enc/vp8i_enc.h"
#ifdef __cplusplus
extern "C" {
#endif
// On-the-fly info about the current set of residuals. Handy to avoid
// passing zillions of params.
typedef struct VP8Residual VP8Residual;
struct VP8Residual {
int first;
int last;
const int16_t* coeffs;
int coeff_type;
ProbaArray* prob;
StatsArray* stats;
CostArrayPtr costs;
};
void VP8InitResidual(int first, int coeff_type,
VP8Encoder* const enc, VP8Residual* const res);
int VP8RecordCoeffs(int ctx, const VP8Residual* const res);
// Record proba context used.
static WEBP_INLINE int VP8RecordStats(int bit, proba_t* const stats) {
proba_t p = *stats;
// An overflow is inbound. Note we handle this at 0xfffe0000u instead of
// 0xffff0000u to make sure p + 1u does not overflow.
if (p >= 0xfffe0000u) {
p = ((p + 1u) >> 1) & 0x7fff7fffu; // -> divide the stats by 2.
}
// record bit count (lower 16 bits) and increment total count (upper 16 bits).
p += 0x00010000u + bit;
*stats = p;
return bit;
}
// Cost of coding one event with probability 'proba'.
static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) {
return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
}
// Level cost calculations
extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
void VP8CalculateLevelCosts(VP8EncProba* const proba);
static WEBP_INLINE int VP8LevelCost(const uint16_t* const table, int level) {
return VP8LevelFixedCosts[level]
+ table[(level > MAX_VARIABLE_LEVEL) ? MAX_VARIABLE_LEVEL : level];
}
// Mode costs
extern const uint16_t VP8FixedCostsUV[4];
extern const uint16_t VP8FixedCostsI16[4];
extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
//------------------------------------------------------------------------------
#ifdef __cplusplus
} // extern "C"
#endif
#endif // WEBP_ENC_COST_ENC_H_