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author | Michael Niedermayer <michaelni@gmx.at> | 2014-05-15 14:50:12 +0200 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2014-05-15 18:20:17 +0200 |
commit | 2c7d3ecfc962fe2d2afa84cd347136060468fe0e (patch) | |
tree | c41ba636d60abccf4acaab315de41823967a033e /libavcodec/opus.h | |
parent | 8b96f31817be57f0542834e7d6bdaecf2db6fd50 (diff) | |
parent | b70d7a4ac72d23f3448f3b08b770fdf5f57de222 (diff) | |
download | ffmpeg-2c7d3ecfc962fe2d2afa84cd347136060468fe0e.tar.gz |
Merge commit 'b70d7a4ac72d23f3448f3b08b770fdf5f57de222'
* commit 'b70d7a4ac72d23f3448f3b08b770fdf5f57de222':
lavc: add a native Opus decoder.
Conflicts:
Changelog
configure
libavcodec/version.h
Fate tests pass with both avresample as well as swresample based opus decoder, but
are disabled (reference files are very large so i want to think a day or 2 about
if theres an alternative or if they could be avoided, they also dont match the
official samples)
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/opus.h')
-rw-r--r-- | libavcodec/opus.h | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/libavcodec/opus.h b/libavcodec/opus.h new file mode 100644 index 0000000000..a6eea02803 --- /dev/null +++ b/libavcodec/opus.h @@ -0,0 +1,429 @@ +/* + * Opus decoder/demuxer common functions + * Copyright (c) 2012 Andrew D'Addesio + * Copyright (c) 2013-2014 Mozilla Corporation + * + * 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_H +#define AVCODEC_OPUS_H + +#include <stdint.h> + +#include "libavutil/audio_fifo.h" +#include "libavutil/float_dsp.h" +#include "libavutil/frame.h" + +#include "libavresample/avresample.h" + +#include "avcodec.h" +#include "get_bits.h" + +#define MAX_FRAME_SIZE 1275 +#define MAX_FRAMES 48 +#define MAX_PACKET_DUR 5760 + +#define CELT_SHORT_BLOCKSIZE 120 +#define CELT_OVERLAP CELT_SHORT_BLOCKSIZE +#define CELT_MAX_LOG_BLOCKS 3 +#define CELT_MAX_FRAME_SIZE (CELT_SHORT_BLOCKSIZE * (1 << CELT_MAX_LOG_BLOCKS)) +#define CELT_MAX_BANDS 21 +#define CELT_VECTORS 11 +#define CELT_ALLOC_STEPS 6 +#define CELT_FINE_OFFSET 21 +#define CELT_MAX_FINE_BITS 8 +#define CELT_NORM_SCALE 16384 +#define CELT_QTHETA_OFFSET 4 +#define CELT_QTHETA_OFFSET_TWOPHASE 16 +#define CELT_DEEMPH_COEFF 0.85000610f +#define CELT_POSTFILTER_MINPERIOD 15 +#define CELT_ENERGY_SILENCE (-28.0f) + +#define SILK_HISTORY 322 +#define SILK_MAX_LPC 16 + +#define ROUND_MULL(a,b,s) (((MUL64(a, b) >> (s - 1)) + 1) >> 1) +#define ROUND_MUL16(a,b) ((MUL16(a, b) + 16384) >> 15) +#define opus_ilog(i) (av_log2(i) + !!(i)) + +enum OpusMode { + OPUS_MODE_SILK, + OPUS_MODE_HYBRID, + OPUS_MODE_CELT +}; + +enum OpusBandwidth { + OPUS_BANDWIDTH_NARROWBAND, + OPUS_BANDWIDTH_MEDIUMBAND, + OPUS_BANDWIDTH_WIDEBAND, + OPUS_BANDWIDTH_SUPERWIDEBAND, + OPUS_BANDWIDTH_FULLBAND +}; + +typedef struct RawBitsContext { + const uint8_t *position; + unsigned int bytes; + unsigned int cachelen; + unsigned int cacheval; +} RawBitsContext; + +typedef struct OpusRangeCoder { + GetBitContext gb; + RawBitsContext rb; + unsigned int range; + unsigned int value; + unsigned int total_read_bits; +} OpusRangeCoder; + +typedef struct SilkContext SilkContext; + +typedef struct CeltIMDCTContext CeltIMDCTContext; + +typedef struct CeltContext CeltContext; + +typedef struct OpusPacket { + int packet_size; /** packet size */ + int data_size; /** size of the useful data -- packet size - padding */ + int code; /** packet code: specifies the frame layout */ + int stereo; /** whether this packet is mono or stereo */ + int vbr; /** vbr flag */ + int config; /** configuration: tells the audio mode, + ** bandwidth, and frame duration */ + int frame_count; /** frame count */ + int frame_offset[MAX_FRAMES]; /** frame offsets */ + int frame_size[MAX_FRAMES]; /** frame sizes */ + int frame_duration; /** frame duration, in samples @ 48kHz */ + enum OpusMode mode; /** mode */ + enum OpusBandwidth bandwidth; /** bandwidth */ +} OpusPacket; + +typedef struct OpusStreamContext { + AVCodecContext *avctx; + int output_channels; + + OpusRangeCoder rc; + OpusRangeCoder redundancy_rc; + SilkContext *silk; + CeltContext *celt; + AVFloatDSPContext *fdsp; + + float silk_buf[2][960]; + float *silk_output[2]; + DECLARE_ALIGNED(32, float, celt_buf)[2][960]; + float *celt_output[2]; + + float redundancy_buf[2][960]; + float *redundancy_output[2]; + + /* data buffers for the final output data */ + float *out[2]; + int out_size; + + float *out_dummy; + int out_dummy_allocated_size; + + AVAudioResampleContext *avr; + AVAudioFifo *celt_delay; + int silk_samplerate; + /* number of samples we still want to get from the resampler */ + int delayed_samples; + + OpusPacket packet; + + int redundancy_idx; +} OpusStreamContext; + +// a mapping between an opus stream and an output channel +typedef struct ChannelMap { + int stream_idx; + int channel_idx; + + // when a single decoded channel is mapped to multiple output channels, we + // write to the first output directly and copy from it to the others + // this field is set to 1 for those copied output channels + int copy; + // this is the index of the output channel to copy from + int copy_idx; + + // this channel is silent + int silence; +} ChannelMap; + +typedef struct OpusContext { + OpusStreamContext *streams; + int nb_streams; + int nb_stereo_streams; + + AVFloatDSPContext fdsp; + int16_t gain_i; + float gain; + + ChannelMap *channel_maps; +} OpusContext; + +static av_always_inline void opus_rc_normalize(OpusRangeCoder *rc) +{ + while (rc->range <= 1<<23) { + rc->value = ((rc->value << 8) | (get_bits(&rc->gb, 8) ^ 0xFF)) & ((1u << 31) - 1); + rc->range <<= 8; + rc->total_read_bits += 8; + } +} + +static av_always_inline void opus_rc_update(OpusRangeCoder *rc, unsigned int scale, + unsigned int low, unsigned int high, + unsigned int total) +{ + rc->value -= scale * (total - high); + rc->range = low ? scale * (high - low) + : rc->range - scale * (total - high); + opus_rc_normalize(rc); +} + +static av_always_inline unsigned int opus_rc_getsymbol(OpusRangeCoder *rc, const uint16_t *cdf) +{ + unsigned int k, scale, total, symbol, low, high; + + total = *cdf++; + + scale = rc->range / total; + symbol = rc->value / scale + 1; + symbol = total - FFMIN(symbol, total); + + for (k = 0; cdf[k] <= symbol; k++); + high = cdf[k]; + low = k ? cdf[k-1] : 0; + + opus_rc_update(rc, scale, low, high, total); + + return k; +} + +static av_always_inline unsigned int opus_rc_p2model(OpusRangeCoder *rc, unsigned int bits) +{ + unsigned int k, scale; + scale = rc->range >> bits; // in this case, scale = symbol + + if (rc->value >= scale) { + rc->value -= scale; + rc->range -= scale; + k = 0; + } else { + rc->range = scale; + k = 1; + } + opus_rc_normalize(rc); + return k; +} + +/** + * CELT: estimate bits of entropy that have thus far been consumed for the + * current CELT frame, to integer and fractional (1/8th bit) precision + */ +static av_always_inline unsigned int opus_rc_tell(const OpusRangeCoder *rc) +{ + return rc->total_read_bits - av_log2(rc->range) - 1; +} + +static av_always_inline unsigned int opus_rc_tell_frac(const OpusRangeCoder *rc) +{ + unsigned int i, total_bits, rcbuffer, range; + + total_bits = rc->total_read_bits << 3; + rcbuffer = av_log2(rc->range) + 1; + range = rc->range >> (rcbuffer-16); + + for (i = 0; i < 3; i++) { + int bit; + range = range * range >> 15; + bit = range >> 16; + rcbuffer = rcbuffer << 1 | bit; + range >>= bit; + } + + return total_bits - rcbuffer; +} + +/** + * CELT: read 1-25 raw bits at the end of the frame, backwards byte-wise + */ +static av_always_inline unsigned int opus_getrawbits(OpusRangeCoder *rc, unsigned int count) +{ + unsigned int value = 0; + + while (rc->rb.bytes && rc->rb.cachelen < count) { + rc->rb.cacheval |= *--rc->rb.position << rc->rb.cachelen; + rc->rb.cachelen += 8; + rc->rb.bytes--; + } + + value = rc->rb.cacheval & ((1<<count)-1); + rc->rb.cacheval >>= count; + rc->rb.cachelen -= count; + rc->total_read_bits += count; + + return value; +} + +/** + * CELT: read a uniform distribution + */ +static av_always_inline unsigned int opus_rc_unimodel(OpusRangeCoder *rc, unsigned int size) +{ + unsigned int bits, k, scale, total; + + bits = opus_ilog(size - 1); + total = (bits > 8) ? ((size - 1) >> (bits - 8)) + 1 : size; + + scale = rc->range / total; + k = rc->value / scale + 1; + k = total - FFMIN(k, total); + opus_rc_update(rc, scale, k, k + 1, total); + + if (bits > 8) { + k = k << (bits - 8) | opus_getrawbits(rc, bits - 8); + return FFMIN(k, size - 1); + } else + return k; +} + +static av_always_inline int opus_rc_laplace(OpusRangeCoder *rc, unsigned int symbol, int decay) +{ + /* extends the range coder to model a Laplace distribution */ + int value = 0; + unsigned int scale, low = 0, center; + + scale = rc->range >> 15; + center = rc->value / scale + 1; + center = (1 << 15) - FFMIN(center, 1 << 15); + + if (center >= symbol) { + value++; + low = symbol; + symbol = 1 + ((32768 - 32 - symbol) * (16384-decay) >> 15); + + while (symbol > 1 && center >= low + 2 * symbol) { + value++; + symbol *= 2; + low += symbol; + symbol = (((symbol - 2) * decay) >> 15) + 1; + } + + if (symbol <= 1) { + int distance = (center - low) >> 1; + value += distance; + low += 2 * distance; + } + + if (center < low + symbol) + value *= -1; + else + low += symbol; + } + + opus_rc_update(rc, scale, low, FFMIN(low + symbol, 32768), 32768); + + return value; +} + +static av_always_inline unsigned int opus_rc_stepmodel(OpusRangeCoder *rc, int k0) +{ + /* Use a probability of 3 up to itheta=8192 and then use 1 after */ + unsigned int k, scale, symbol, total = (k0+1)*3 + k0; + scale = rc->range / total; + symbol = rc->value / scale + 1; + symbol = total - FFMIN(symbol, total); + + k = (symbol < (k0+1)*3) ? symbol/3 : symbol - (k0+1)*2; + + opus_rc_update(rc, scale, (k <= k0) ? 3*(k+0) : (k-1-k0) + 3*(k0+1), + (k <= k0) ? 3*(k+1) : (k-0-k0) + 3*(k0+1), total); + return k; +} + +static av_always_inline unsigned int opus_rc_trimodel(OpusRangeCoder *rc, int qn) +{ + unsigned int k, scale, symbol, total, low, center; + + total = ((qn>>1) + 1) * ((qn>>1) + 1); + scale = rc->range / total; + center = rc->value / scale + 1; + center = total - FFMIN(center, total); + + if (center < total >> 1) { + k = (ff_sqrt(8 * center + 1) - 1) >> 1; + low = k * (k + 1) >> 1; + symbol = k + 1; + } else { + k = (2*(qn + 1) - ff_sqrt(8*(total - center - 1) + 1)) >> 1; + low = total - ((qn + 1 - k) * (qn + 2 - k) >> 1); + symbol = qn + 1 - k; + } + + opus_rc_update(rc, scale, low, low + symbol, total); + + return k; +} + +int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size, + int self_delimited); + +int ff_opus_parse_extradata(AVCodecContext *avctx, OpusContext *s); + +int ff_silk_init(AVCodecContext *avctx, SilkContext **ps, int output_channels); +void ff_silk_free(SilkContext **ps); +void ff_silk_flush(SilkContext *s); + +/** + * Decode the LP layer of one Opus frame (which may correspond to several SILK + * frames). + */ +int ff_silk_decode_superframe(SilkContext *s, OpusRangeCoder *rc, + float *output[2], + enum OpusBandwidth bandwidth, int coded_channels, + int duration_ms); + +/** + * Init an iMDCT of the length 2 * 15 * (2^N) + */ +int ff_celt_imdct_init(CeltIMDCTContext **s, int N); + +/** + * Free an iMDCT. + */ +void ff_celt_imdct_uninit(CeltIMDCTContext **s); + +/** + * Calculate the middle half of the iMDCT + */ +void ff_celt_imdct_half(CeltIMDCTContext *s, float *dst, const float *src, + int src_stride, float scale); + +int ff_celt_init(AVCodecContext *avctx, CeltContext **s, int output_channels); + +void ff_celt_free(CeltContext **s); + +void ff_celt_flush(CeltContext *s); + +int ff_celt_decode_frame(CeltContext *s, OpusRangeCoder *rc, + float **output, int coded_channels, int frame_size, + int startband, int endband); + +extern const float ff_celt_window2[120]; + +#endif /* AVCODEC_OPUS_H */ |