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https://github.com/FFmpeg/FFmpeg.git
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2ad1768c7b
This commit implements a psychoacoustic system for the native Opus encoder. Its unlike any other psychoacoustic system known since its capable of using a lookahead to make better choices on how to treat the current frame and how many bits to allocate for it (and future frames). Also, whilst the main bulk of the analysis function has to run in a single thread, the per-frame anaylsis functions does not modify the main psychoacoustic context, so in the future it will be fairly trivial to run those as slice threads. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
169 lines
4.6 KiB
C
169 lines
4.6 KiB
C
/*
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* Opus decoder/demuxer common functions
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* Copyright (c) 2012 Andrew D'Addesio
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* Copyright (c) 2013-2014 Mozilla Corporation
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* Copyright (c) 2016 Rostislav Pehlivanov <atomnuker@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVCODEC_OPUS_CELT_H
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#define AVCODEC_OPUS_CELT_H
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#include <float.h>
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#include "opus.h"
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#include "opus_pvq.h"
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#include "mdct15.h"
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#include "libavutil/float_dsp.h"
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#include "libavutil/libm.h"
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#define CELT_VECTORS 11
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#define CELT_ALLOC_STEPS 6
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#define CELT_FINE_OFFSET 21
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#define CELT_MAX_FINE_BITS 8
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#define CELT_NORM_SCALE 16384
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#define CELT_QTHETA_OFFSET 4
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#define CELT_QTHETA_OFFSET_TWOPHASE 16
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#define CELT_EMPH_COEFF 0.85000610f
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#define CELT_POSTFILTER_MINPERIOD 15
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#define CELT_ENERGY_SILENCE (-28.0f)
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typedef struct CeltPVQ CeltPVQ;
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enum CeltSpread {
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CELT_SPREAD_NONE,
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CELT_SPREAD_LIGHT,
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CELT_SPREAD_NORMAL,
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CELT_SPREAD_AGGRESSIVE
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};
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enum CeltBlockSize {
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CELT_BLOCK_120,
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CELT_BLOCK_240,
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CELT_BLOCK_480,
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CELT_BLOCK_960,
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CELT_BLOCK_NB
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};
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typedef struct CeltBlock {
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float energy[CELT_MAX_BANDS];
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float lin_energy[CELT_MAX_BANDS];
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float error_energy[CELT_MAX_BANDS];
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float prev_energy[2][CELT_MAX_BANDS];
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uint8_t collapse_masks[CELT_MAX_BANDS];
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/* buffer for mdct output + postfilter */
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DECLARE_ALIGNED(32, float, buf)[2048];
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DECLARE_ALIGNED(32, float, coeffs)[CELT_MAX_FRAME_SIZE];
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/* Used by the encoder */
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DECLARE_ALIGNED(32, float, overlap)[FFALIGN(CELT_OVERLAP, 16)];
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DECLARE_ALIGNED(32, float, samples)[FFALIGN(CELT_MAX_FRAME_SIZE, 16)];
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/* postfilter parameters */
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int pf_period_new;
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float pf_gains_new[3];
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int pf_period;
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float pf_gains[3];
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int pf_period_old;
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float pf_gains_old[3];
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float emph_coeff;
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} CeltBlock;
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struct CeltFrame {
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// constant values that do not change during context lifetime
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AVCodecContext *avctx;
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MDCT15Context *imdct[4];
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AVFloatDSPContext *dsp;
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CeltBlock block[2];
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CeltPVQ *pvq;
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int channels;
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int output_channels;
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enum CeltBlockSize size;
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int start_band;
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int end_band;
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int coded_bands;
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int transient;
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int pfilter;
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int skip_band_floor;
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int tf_select;
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int alloc_trim;
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int alloc_boost[CELT_MAX_BANDS];
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int blocks; /* number of iMDCT blocks in the frame, depends on transient */
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int blocksize; /* size of each block */
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int silence; /* Frame is filled with silence */
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int anticollapse_needed; /* Whether to expect an anticollapse bit */
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int anticollapse; /* Encoded anticollapse bit */
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int intensity_stereo;
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int dual_stereo;
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int flushed;
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uint32_t seed;
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enum CeltSpread spread;
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/* Encoder PF coeffs */
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int pf_octave;
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int pf_period;
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int pf_tapset;
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float pf_gain;
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/* Bit allocation */
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int framebits;
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int remaining;
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int remaining2;
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int caps [CELT_MAX_BANDS];
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int fine_bits [CELT_MAX_BANDS];
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int fine_priority[CELT_MAX_BANDS];
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int pulses [CELT_MAX_BANDS];
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int tf_change [CELT_MAX_BANDS];
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};
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/* LCG for noise generation */
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static av_always_inline uint32_t celt_rng(CeltFrame *f)
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{
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f->seed = 1664525 * f->seed + 1013904223;
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return f->seed;
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}
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static av_always_inline void celt_renormalize_vector(float *X, int N, float gain)
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{
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int i;
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float g = 1e-15f;
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for (i = 0; i < N; i++)
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g += X[i] * X[i];
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g = gain / sqrtf(g);
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for (i = 0; i < N; i++)
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X[i] *= g;
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}
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int ff_celt_init(AVCodecContext *avctx, CeltFrame **f, int output_channels);
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void ff_celt_free(CeltFrame **f);
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void ff_celt_flush(CeltFrame *f);
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int ff_celt_decode_frame(CeltFrame *f, OpusRangeCoder *rc, float **output,
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int coded_channels, int frame_size, int startband, int endband);
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#endif /* AVCODEC_OPUS_CELT_H */
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