virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-18 03:19:31 +02:00
Code Issues Releases Activity
a88db8b9a0
FFmpeg/libavcodec/opus_pvq.h

42 lines
1.7 KiB
C
Raw Normal View History

opus_celt: move quantization and band decoding to opus_pvq.c A huge amount can be reused by the encoder, as the only thing which needs to be done would be to add a 10 line celt_icwrsi, a wrapper around it (celt_alg_quant) and templating the ff_celt_decode_band to replace entropy decoding functions with entropy encoding. There is no performance loss but in fact a performance gain of around 6% which is caused by the compiler being able to optimize the decoding more efficiently. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-11 02:25:06 +02:00
/*
* Copyright (c) 2012 Andrew D'Addesio
* Copyright (c) 2013-2014 Mozilla Corporation
* Copyright (c) 2016 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_OPUS_PVQ_H
#define AVCODEC_OPUS_PVQ_H
#include "opus.h"
#include "opus_celt.h"
/* Decodes a band using PVQ */
opus_celt: rename structures to better names and reorganize them This is meant to be applied on top of my previous patch which split PVQ into celt_pvq.c and made opus_celt.h Essentially nothing has been changed other than renaming CeltFrame to CeltBlock (CeltFrame had absolutely nothing at all to do with a frame) and CeltContext to CeltFrame. 3 variables have been put in CeltFrame as they make more sense there rather than being passed around as arguments. The coefficients have been moved to the CeltBlock structure (why the hell were they in CeltContext and not in CeltFrame??). Now the encoder would be able to use the exact context the decoder uses (plus a couple of extra fields in there). FATE passes, no slowdowns, etc. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-11 02:25:07 +02:00
uint32_t ff_celt_decode_band(CeltFrame *f, OpusRangeCoder *rc, const int band,
opus_celt: move quantization and band decoding to opus_pvq.c A huge amount can be reused by the encoder, as the only thing which needs to be done would be to add a 10 line celt_icwrsi, a wrapper around it (celt_alg_quant) and templating the ff_celt_decode_band to replace entropy decoding functions with entropy encoding. There is no performance loss but in fact a performance gain of around 6% which is caused by the compiler being able to optimize the decoding more efficiently. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-11 02:25:06 +02:00
float *X, float *Y, int N, int b, uint32_t blocks,
float *lowband, int duration, float *lowband_out, int level,
float gain, float *lowband_scratch, int fill);
opus: add a native Opus encoder This marks the first time anyone has written an Opus encoder without using any libopus code. The aim of the encoder is to prove how far the format can go by writing the craziest encoder for it. Right now the encoder's basic, it only supports CBR encoding, however internally every single feature the CELT layer has is implemented (except the pitch pre-filter which needs to work well with the rest of whatever gets implemented). Psychoacoustic and rate control systems are under development. The encoder takes in frames of 120 samples and depending on the value of opus_delay the plan is to use the extra buffered frames as lookahead. Right now the encoder will pick the nearest largest legal frame size and won't use the lookahead, but that'll change once there's a psychoacoustic system. Even though its a pretty basic encoder its already outperforming any other native encoder FFmpeg has by a huge amount. The PVQ search algorithm is faster and more accurate than libopus's algorithm so the encoder's performance is close to that of libopus at zero complexity (libopus has more SIMD). The algorithm might be ported to libopus or other codecs using PVQ in the future. The encoder still has a few minor bugs, like desyncs at ultra low bitrates (below 9kbps with 20ms frames). Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-11 02:25:08 +02:00
/* Encodes a band using PVQ */
uint32_t ff_celt_encode_band(CeltFrame *f, OpusRangeCoder *rc, const int band,
float *X, float *Y, int N, int b, uint32_t blocks,
float *lowband, int duration, float *lowband_out, int level,
float gain, float *lowband_scratch, int fill);
opus_celt: move quantization and band decoding to opus_pvq.c A huge amount can be reused by the encoder, as the only thing which needs to be done would be to add a 10 line celt_icwrsi, a wrapper around it (celt_alg_quant) and templating the ff_celt_decode_band to replace entropy decoding functions with entropy encoding. There is no performance loss but in fact a performance gain of around 6% which is caused by the compiler being able to optimize the decoding more efficiently. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-11 02:25:06 +02:00
#endif /* AVCODEC_OPUS_PVQ_H */
Reference in New Issue Copy Permalink