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/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#ifndef AOM_AV1_ENCODER_COST_H_
#define AOM_AV1_ENCODER_COST_H_
#include "aom_dsp/prob.h"
#include "aom/aom_integer.h"
#ifdef __cplusplus
extern "C" {
#endif
extern const uint16_t av1_prob_cost[128];
// The factor to scale from cost in bits to cost in av1_prob_cost units.
#define AV1_PROB_COST_SHIFT 9
// Cost of coding an n bit literal, using 128 (i.e. 50%) probability
// for each bit.
#define av1_cost_literal(n) ((n) * (1 << AV1_PROB_COST_SHIFT))
// Calculate the cost of a symbol with probability p15 / 2^15
static INLINE int av1_cost_symbol(aom_cdf_prob p15) {
// p15 can be out of range [1, CDF_PROB_TOP - 1]. Clamping it, so that the
// following cost calculation works correctly. Otherwise, if p15 =
// CDF_PROB_TOP, shift would be -1, and "p15 << shift" would be wrong.
p15 = (aom_cdf_prob)clamp(p15, 1, CDF_PROB_TOP - 1);
assert(0 < p15 && p15 < CDF_PROB_TOP);
const int shift = CDF_PROB_BITS - 1 - get_msb(p15);
const int prob = get_prob(p15 << shift, CDF_PROB_TOP);
assert(prob >= 128);
return av1_prob_cost[prob - 128] + av1_cost_literal(shift);
}
void av1_cost_tokens_from_cdf(int *costs, const aom_cdf_prob *cdf,
const int *inv_map);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_AV1_ENCODER_COST_H_
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