// 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_ */