godot/thirdparty/libwebp/src/enc/cost_enc.c

// 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 ([email protected])

#include "src/enc/cost_enc.h"

//------------------------------------------------------------------------------
// Level cost tables

// For each given level, the following table gives the pattern of contexts to
// use for coding it (in [][0]) as well as the bit value to use for each
// context (in [][1]).
const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2] = …;

static int VariableLevelCost(int level, const uint8_t probas[NUM_PROBAS]) { … }

//------------------------------------------------------------------------------
// Pre-calc level costs once for all

void VP8CalculateLevelCosts(VP8EncProba* const proba) { … }

//------------------------------------------------------------------------------
// Mode cost tables.

// These are the fixed probabilities (in the coding trees) turned into bit-cost
// by calling VP8BitCost().
const uint16_t VP8FixedCostsUV[4] = …;
// note: these values include the fixed VP8BitCost(1, 145) mode selection cost.
const uint16_t VP8FixedCostsI16[4] = …;
const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES] = …;

//------------------------------------------------------------------------------
// helper functions for residuals struct VP8Residual.

void VP8InitResidual(int first, int coeff_type,
                     VP8Encoder* const enc, VP8Residual* const res) { … }

//------------------------------------------------------------------------------
// Mode costs

int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]) { … }

int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd) { … }

int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd) { … }


//------------------------------------------------------------------------------
// Recording of token probabilities.

// We keep the table-free variant around for reference, in case.
#define USE_LEVEL_CODE_TABLE

// Simulate block coding, but only record statistics.
// Note: no need to record the fixed probas.
int VP8RecordCoeffs(int ctx, const VP8Residual* const res) { … }

//------------------------------------------------------------------------------