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83 lines
2.5 KiB
C
83 lines
2.5 KiB
C
// Copyright 2011 Google Inc. All Rights Reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the COPYING file in the root of the source
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// tree. An additional intellectual property rights grant can be found
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// in the file PATENTS. All contributing project authors may
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// be found in the AUTHORS file in the root of the source tree.
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// -----------------------------------------------------------------------------
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//
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// Cost tables for level and modes.
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//
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// Author: Skal (pascal.massimino@gmail.com)
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#ifndef WEBP_ENC_COST_ENC_H_
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#define WEBP_ENC_COST_ENC_H_
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#include <assert.h>
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#include <stdlib.h>
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#include "src/enc/vp8i_enc.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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// On-the-fly info about the current set of residuals. Handy to avoid
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// passing zillions of params.
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typedef struct VP8Residual VP8Residual;
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struct VP8Residual {
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int first;
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int last;
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const int16_t* coeffs;
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int coeff_type;
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ProbaArray* prob;
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StatsArray* stats;
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CostArrayPtr costs;
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};
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void VP8InitResidual(int first, int coeff_type,
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VP8Encoder* const enc, VP8Residual* const res);
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int VP8RecordCoeffs(int ctx, const VP8Residual* const res);
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// Record proba context used.
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static WEBP_INLINE int VP8RecordStats(int bit, proba_t* const stats) {
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proba_t p = *stats;
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// An overflow is inbound. Note we handle this at 0xfffe0000u instead of
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// 0xffff0000u to make sure p + 1u does not overflow.
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if (p >= 0xfffe0000u) {
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p = ((p + 1u) >> 1) & 0x7fff7fffu; // -> divide the stats by 2.
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}
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// record bit count (lower 16 bits) and increment total count (upper 16 bits).
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p += 0x00010000u + bit;
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*stats = p;
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return bit;
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}
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// Cost of coding one event with probability 'proba'.
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static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) {
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return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba];
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}
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// Level cost calculations
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extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2];
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void VP8CalculateLevelCosts(VP8EncProba* const proba);
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static WEBP_INLINE int VP8LevelCost(const uint16_t* const table, int level) {
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return VP8LevelFixedCosts[level]
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+ table[(level > MAX_VARIABLE_LEVEL) ? MAX_VARIABLE_LEVEL : level];
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}
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// Mode costs
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extern const uint16_t VP8FixedCostsUV[4];
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extern const uint16_t VP8FixedCostsI16[4];
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extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES];
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//------------------------------------------------------------------------------
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#endif // WEBP_ENC_COST_ENC_H_
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