FFmpeg/libavcodec/opusenc.h
Rostislav Pehlivanov 2ad1768c7b opusenc: implement a psychoacoustic system
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>
2017-09-23 08:27:44 +01:00

57 lines
1.7 KiB
C

/*
* Opus encoder
* Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_OPUSENC_H
#define AVCODEC_OPUSENC_H
#include "internal.h"
#include "opus_celt.h"
/* Determines the maximum delay the psychoacoustic system will use for lookahead */
#define FF_BUFQUEUE_SIZE 145
#include "libavfilter/bufferqueue.h"
#define OPUS_MAX_LOOKAHEAD ((FF_BUFQUEUE_SIZE - 1)*2.5f)
#define OPUS_MAX_CHANNELS 2
/* 120 ms / 2.5 ms = 48 frames (extremely improbable, but the encoder'll work) */
#define OPUS_MAX_FRAMES_PER_PACKET 48
#define OPUS_BLOCK_SIZE(x) (2 * 15 * (1 << ((x) + 2)))
#define OPUS_SAMPLES_TO_BLOCK_SIZE(x) (ff_log2((x) / (2 * 15)) - 2)
typedef struct OpusEncOptions {
float max_delay_ms;
} OpusEncOptions;
typedef struct OpusPacketInfo {
enum OpusMode mode;
enum OpusBandwidth bandwidth;
int framesize;
int frames;
} OpusPacketInfo;
void ff_celt_enc_bitalloc(OpusRangeCoder *rc, CeltFrame *f);
#endif /* AVCODEC_OPUSENC_H */