1 /* 2 * Opus decoder/demuxer common functions 3 * Copyright (c) 2012 Andrew D'Addesio 4 * Copyright (c) 2013-2014 Mozilla Corporation 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23 #ifndef AVCODEC_OPUS_H 24 #define AVCODEC_OPUS_H 25 26 #include <stdint.h> 27 28 #include "libavutil/audio_fifo.h" 29 #include "libavutil/float_dsp.h" 30 #include "libavutil/frame.h" 31 32 #include "libswresample/swresample.h" 33 34 #include "avcodec.h" 35 #include "opus_rc.h" 36 37 #define MAX_FRAME_SIZE 1275 38 #define MAX_FRAMES 48 39 #define MAX_PACKET_DUR 5760 40 41 #define CELT_SHORT_BLOCKSIZE 120 42 #define CELT_OVERLAP CELT_SHORT_BLOCKSIZE 43 #define CELT_MAX_LOG_BLOCKS 3 44 #define CELT_MAX_FRAME_SIZE (CELT_SHORT_BLOCKSIZE * (1 << CELT_MAX_LOG_BLOCKS)) 45 #define CELT_MAX_BANDS 21 46 47 #define SILK_HISTORY 322 48 #define SILK_MAX_LPC 16 49 50 #define ROUND_MULL(a,b,s) (((MUL64(a, b) >> ((s) - 1)) + 1) >> 1) 51 #define ROUND_MUL16(a,b) ((MUL16(a, b) + 16384) >> 15) 52 53 #define OPUS_TS_HEADER 0x7FE0 // 0x3ff (11 bits) 54 #define OPUS_TS_MASK 0xFFE0 // top 11 bits 55 56 static const uint8_t opus_default_extradata[30] = { 57 'O', 'p', 'u', 's', 'H', 'e', 'a', 'd', 58 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 59 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 60 }; 61 62 enum OpusMode { 63 OPUS_MODE_SILK, 64 OPUS_MODE_HYBRID, 65 OPUS_MODE_CELT, 66 67 OPUS_MODE_NB 68 }; 69 70 enum OpusBandwidth { 71 OPUS_BANDWIDTH_NARROWBAND, 72 OPUS_BANDWIDTH_MEDIUMBAND, 73 OPUS_BANDWIDTH_WIDEBAND, 74 OPUS_BANDWIDTH_SUPERWIDEBAND, 75 OPUS_BANDWIDTH_FULLBAND, 76 77 OPUS_BANDWITH_NB 78 }; 79 80 typedef struct SilkContext SilkContext; 81 82 typedef struct CeltFrame CeltFrame; 83 84 typedef struct OpusPacket { 85 int packet_size; /**< packet size */ 86 int data_size; /**< size of the useful data -- packet size - padding */ 87 int code; /**< packet code: specifies the frame layout */ 88 int stereo; /**< whether this packet is mono or stereo */ 89 int vbr; /**< vbr flag */ 90 int config; /**< configuration: tells the audio mode, 91 ** bandwidth, and frame duration */ 92 int frame_count; /**< frame count */ 93 int frame_offset[MAX_FRAMES]; /**< frame offsets */ 94 int frame_size[MAX_FRAMES]; /**< frame sizes */ 95 int frame_duration; /**< frame duration, in samples @ 48kHz */ 96 enum OpusMode mode; /**< mode */ 97 enum OpusBandwidth bandwidth; /**< bandwidth */ 98 } OpusPacket; 99 100 typedef struct OpusStreamContext { 101 AVCodecContext *avctx; 102 int output_channels; 103 104 OpusRangeCoder rc; 105 OpusRangeCoder redundancy_rc; 106 SilkContext *silk; 107 CeltFrame *celt; 108 AVFloatDSPContext *fdsp; 109 110 float silk_buf[2][960]; 111 float *silk_output[2]; 112 DECLARE_ALIGNED(32, float, celt_buf)[2][960]; 113 float *celt_output[2]; 114 115 DECLARE_ALIGNED(32, float, redundancy_buf)[2][960]; 116 float *redundancy_output[2]; 117 118 /* data buffers for the final output data */ 119 float *out[2]; 120 int out_size; 121 122 float *out_dummy; 123 int out_dummy_allocated_size; 124 125 SwrContext *swr; 126 AVAudioFifo *celt_delay; 127 int silk_samplerate; 128 /* number of samples we still want to get from the resampler */ 129 int delayed_samples; 130 131 OpusPacket packet; 132 133 int redundancy_idx; 134 } OpusStreamContext; 135 136 // a mapping between an opus stream and an output channel 137 typedef struct ChannelMap { 138 int stream_idx; 139 int channel_idx; 140 141 // when a single decoded channel is mapped to multiple output channels, we 142 // write to the first output directly and copy from it to the others 143 // this field is set to 1 for those copied output channels 144 int copy; 145 // this is the index of the output channel to copy from 146 int copy_idx; 147 148 // this channel is silent 149 int silence; 150 } ChannelMap; 151 152 typedef struct OpusContext { 153 AVClass *av_class; 154 OpusStreamContext *streams; 155 int apply_phase_inv; 156 157 /* current output buffers for each streams */ 158 float **out; 159 int *out_size; 160 /* Buffers for synchronizing the streams when they have different 161 * resampling delays */ 162 AVAudioFifo **sync_buffers; 163 /* number of decoded samples for each stream */ 164 int *decoded_samples; 165 166 int nb_streams; 167 int nb_stereo_streams; 168 169 AVFloatDSPContext *fdsp; 170 int16_t gain_i; 171 float gain; 172 173 ChannelMap *channel_maps; 174 } OpusContext; 175 176 int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size, 177 int self_delimited); 178 179 int ff_opus_parse_extradata(AVCodecContext *avctx, OpusContext *s); 180 181 int ff_silk_init(AVCodecContext *avctx, SilkContext **ps, int output_channels); 182 void ff_silk_free(SilkContext **ps); 183 void ff_silk_flush(SilkContext *s); 184 185 /** 186 * Decode the LP layer of one Opus frame (which may correspond to several SILK 187 * frames). 188 */ 189 int ff_silk_decode_superframe(SilkContext *s, OpusRangeCoder *rc, 190 float *output[2], 191 enum OpusBandwidth bandwidth, int coded_channels, 192 int duration_ms); 193 194 /* Encode or decode CELT bands */ 195 void ff_celt_quant_bands(CeltFrame *f, OpusRangeCoder *rc); 196 197 /* Encode or decode CELT bitallocation */ 198 void ff_celt_bitalloc(CeltFrame *f, OpusRangeCoder *rc, int encode); 199 200 #endif /* AVCODEC_OPUS_H */ 201