1/* 2 * Copyright (C) 2009 Justin Ruggles 3 * Copyright (c) 2009 Xuggle Incorporated 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * libspeex Speex audio encoder 25 * 26 * Usage Guide 27 * This explains the values that need to be set prior to initialization in 28 * order to control various encoding parameters. 29 * 30 * Channels 31 * Speex only supports mono or stereo, so avctx->channels must be set to 32 * 1 or 2. 33 * 34 * Sample Rate / Encoding Mode 35 * Speex has 3 modes, each of which uses a specific sample rate. 36 * narrowband : 8 kHz 37 * wideband : 16 kHz 38 * ultra-wideband : 32 kHz 39 * avctx->sample_rate must be set to one of these 3 values. This will be 40 * used to set the encoding mode. 41 * 42 * Rate Control 43 * VBR mode is turned on by setting CODEC_FLAG_QSCALE in avctx->flags. 44 * avctx->global_quality is used to set the encoding quality. 45 * For CBR mode, avctx->bit_rate can be used to set the constant bitrate. 46 * Alternatively, the 'cbr_quality' option can be set from 0 to 10 to set 47 * a constant bitrate based on quality. 48 * For ABR mode, set avctx->bit_rate and set the 'abr' option to 1. 49 * Approx. Bitrate Range: 50 * narrowband : 2400 - 25600 bps 51 * wideband : 4000 - 43200 bps 52 * ultra-wideband : 4400 - 45200 bps 53 * 54 * Complexity 55 * Encoding complexity is controlled by setting avctx->compression_level. 56 * The valid range is 0 to 10. A higher setting gives generally better 57 * quality at the expense of encoding speed. This does not affect the 58 * bit rate. 59 * 60 * Frames-per-Packet 61 * The encoder defaults to using 1 frame-per-packet. However, it is 62 * sometimes desirable to use multiple frames-per-packet to reduce the 63 * amount of container overhead. This can be done by setting the 64 * 'frames_per_packet' option to a value 1 to 8. 65 * 66 * 67 * Optional features 68 * Speex encoder supports several optional features, which can be useful 69 * for some conditions. 70 * 71 * Voice Activity Detection 72 * When enabled, voice activity detection detects whether the audio 73 * being encoded is speech or silence/background noise. VAD is always 74 * implicitly activated when encoding in VBR, so the option is only useful 75 * in non-VBR operation. In this case, Speex detects non-speech periods and 76 * encodes them with just enough bits to reproduce the background noise. 77 * 78 * Discontinuous Transmission (DTX) 79 * DTX is an addition to VAD/VBR operation, that allows to stop transmitting 80 * completely when the background noise is stationary. 81 * In file-based operation only 5 bits are used for such frames. 82 */ 83 84#include <speex/speex.h> 85#include <speex/speex_header.h> 86#include <speex/speex_stereo.h> 87 88#include "libavutil/channel_layout.h" 89#include "libavutil/common.h" 90#include "libavutil/opt.h" 91#include "avcodec.h" 92#include "internal.h" 93#include "audio_frame_queue.h" 94 95/* TODO: Think about converting abr, vad, dtx and such flags to a bit field */ 96typedef struct { 97 AVClass *class; ///< AVClass for private options 98 SpeexBits bits; ///< libspeex bitwriter context 99 SpeexHeader header; ///< libspeex header struct 100 void *enc_state; ///< libspeex encoder state 101 int frames_per_packet; ///< number of frames to encode in each packet 102 float vbr_quality; ///< VBR quality 0.0 to 10.0 103 int cbr_quality; ///< CBR quality 0 to 10 104 int abr; ///< flag to enable ABR 105 int vad; ///< flag to enable VAD 106 int dtx; ///< flag to enable DTX 107 int pkt_frame_count; ///< frame count for the current packet 108 AudioFrameQueue afq; ///< frame queue 109} LibSpeexEncContext; 110 111static av_cold void print_enc_params(AVCodecContext *avctx, 112 LibSpeexEncContext *s) 113{ 114 const char *mode_str = "unknown"; 115 116 av_log(avctx, AV_LOG_DEBUG, "channels: %d\n", avctx->channels); 117 switch (s->header.mode) { 118 case SPEEX_MODEID_NB: mode_str = "narrowband"; break; 119 case SPEEX_MODEID_WB: mode_str = "wideband"; break; 120 case SPEEX_MODEID_UWB: mode_str = "ultra-wideband"; break; 121 } 122 av_log(avctx, AV_LOG_DEBUG, "mode: %s\n", mode_str); 123 if (s->header.vbr) { 124 av_log(avctx, AV_LOG_DEBUG, "rate control: VBR\n"); 125 av_log(avctx, AV_LOG_DEBUG, " quality: %f\n", s->vbr_quality); 126 } else if (s->abr) { 127 av_log(avctx, AV_LOG_DEBUG, "rate control: ABR\n"); 128 av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); 129 } else { 130 av_log(avctx, AV_LOG_DEBUG, "rate control: CBR\n"); 131 av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); 132 } 133 av_log(avctx, AV_LOG_DEBUG, "complexity: %d\n", 134 avctx->compression_level); 135 av_log(avctx, AV_LOG_DEBUG, "frame size: %d samples\n", 136 avctx->frame_size); 137 av_log(avctx, AV_LOG_DEBUG, "frames per packet: %d\n", 138 s->frames_per_packet); 139 av_log(avctx, AV_LOG_DEBUG, "packet size: %d\n", 140 avctx->frame_size * s->frames_per_packet); 141 av_log(avctx, AV_LOG_DEBUG, "voice activity detection: %d\n", s->vad); 142 av_log(avctx, AV_LOG_DEBUG, "discontinuous transmission: %d\n", s->dtx); 143} 144 145static av_cold int encode_init(AVCodecContext *avctx) 146{ 147 LibSpeexEncContext *s = avctx->priv_data; 148 const SpeexMode *mode; 149 uint8_t *header_data; 150 int header_size; 151 int32_t complexity; 152 153 /* channels */ 154 if (avctx->channels < 1 || avctx->channels > 2) { 155 av_log(avctx, AV_LOG_ERROR, "Invalid channels (%d). Only stereo and " 156 "mono are supported\n", avctx->channels); 157 return AVERROR(EINVAL); 158 } 159 160 /* sample rate and encoding mode */ 161 switch (avctx->sample_rate) { 162 case 8000: mode = &speex_nb_mode; break; 163 case 16000: mode = &speex_wb_mode; break; 164 case 32000: mode = &speex_uwb_mode; break; 165 default: 166 av_log(avctx, AV_LOG_ERROR, "Sample rate of %d Hz is not supported. " 167 "Resample to 8, 16, or 32 kHz.\n", avctx->sample_rate); 168 return AVERROR(EINVAL); 169 } 170 171 /* initialize libspeex */ 172 s->enc_state = speex_encoder_init(mode); 173 if (!s->enc_state) { 174 av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex\n"); 175 return -1; 176 } 177 speex_init_header(&s->header, avctx->sample_rate, avctx->channels, mode); 178 179 /* rate control method and parameters */ 180 if (avctx->flags & CODEC_FLAG_QSCALE) { 181 /* VBR */ 182 s->header.vbr = 1; 183 s->vad = 1; /* VAD is always implicitly activated for VBR */ 184 speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR, &s->header.vbr); 185 s->vbr_quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA, 186 0.0f, 10.0f); 187 speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR_QUALITY, &s->vbr_quality); 188 } else { 189 s->header.bitrate = avctx->bit_rate; 190 if (avctx->bit_rate > 0) { 191 /* CBR or ABR by bitrate */ 192 if (s->abr) { 193 speex_encoder_ctl(s->enc_state, SPEEX_SET_ABR, 194 &s->header.bitrate); 195 speex_encoder_ctl(s->enc_state, SPEEX_GET_ABR, 196 &s->header.bitrate); 197 } else { 198 speex_encoder_ctl(s->enc_state, SPEEX_SET_BITRATE, 199 &s->header.bitrate); 200 speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, 201 &s->header.bitrate); 202 } 203 } else { 204 /* CBR by quality */ 205 speex_encoder_ctl(s->enc_state, SPEEX_SET_QUALITY, 206 &s->cbr_quality); 207 speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, 208 &s->header.bitrate); 209 } 210 /* stereo side information adds about 800 bps to the base bitrate */ 211 /* TODO: this should be calculated exactly */ 212 avctx->bit_rate = s->header.bitrate + (avctx->channels == 2 ? 800 : 0); 213 } 214 215 /* VAD is activated with VBR or can be turned on by itself */ 216 if (s->vad) 217 speex_encoder_ctl(s->enc_state, SPEEX_SET_VAD, &s->vad); 218 219 /* Activiting Discontinuous Transmission */ 220 if (s->dtx) { 221 speex_encoder_ctl(s->enc_state, SPEEX_SET_DTX, &s->dtx); 222 if (!(s->abr || s->vad || s->header.vbr)) 223 av_log(avctx, AV_LOG_WARNING, "DTX is not much of use without ABR, VAD or VBR\n"); 224 } 225 226 /* set encoding complexity */ 227 if (avctx->compression_level > FF_COMPRESSION_DEFAULT) { 228 complexity = av_clip(avctx->compression_level, 0, 10); 229 speex_encoder_ctl(s->enc_state, SPEEX_SET_COMPLEXITY, &complexity); 230 } 231 speex_encoder_ctl(s->enc_state, SPEEX_GET_COMPLEXITY, &complexity); 232 avctx->compression_level = complexity; 233 234 /* set packet size */ 235 avctx->frame_size = s->header.frame_size; 236 s->header.frames_per_packet = s->frames_per_packet; 237 238 /* set encoding delay */ 239 speex_encoder_ctl(s->enc_state, SPEEX_GET_LOOKAHEAD, &avctx->delay); 240 ff_af_queue_init(avctx, &s->afq); 241 242 /* create header packet bytes from header struct */ 243 /* note: libspeex allocates the memory for header_data, which is freed 244 below with speex_header_free() */ 245 header_data = speex_header_to_packet(&s->header, &header_size); 246 247 /* allocate extradata and coded_frame */ 248 avctx->extradata = av_malloc(header_size + FF_INPUT_BUFFER_PADDING_SIZE); 249 if (!avctx->extradata) { 250 speex_header_free(header_data); 251 speex_encoder_destroy(s->enc_state); 252 av_log(avctx, AV_LOG_ERROR, "memory allocation error\n"); 253 return AVERROR(ENOMEM); 254 } 255 256 /* copy header packet to extradata */ 257 memcpy(avctx->extradata, header_data, header_size); 258 avctx->extradata_size = header_size; 259 speex_header_free(header_data); 260 261 /* init libspeex bitwriter */ 262 speex_bits_init(&s->bits); 263 264 print_enc_params(avctx, s); 265 return 0; 266} 267 268static int encode_frame(AVCodecContext *avctx, AVPacket *avpkt, 269 const AVFrame *frame, int *got_packet_ptr) 270{ 271 LibSpeexEncContext *s = avctx->priv_data; 272 int16_t *samples = frame ? (int16_t *)frame->data[0] : NULL; 273 int ret; 274 275 if (samples) { 276 /* encode Speex frame */ 277 if (avctx->channels == 2) 278 speex_encode_stereo_int(samples, s->header.frame_size, &s->bits); 279 speex_encode_int(s->enc_state, samples, &s->bits); 280 s->pkt_frame_count++; 281 if ((ret = ff_af_queue_add(&s->afq, frame)) < 0) 282 return ret; 283 } else { 284 /* handle end-of-stream */ 285 if (!s->pkt_frame_count) 286 return 0; 287 /* add extra terminator codes for unused frames in last packet */ 288 while (s->pkt_frame_count < s->frames_per_packet) { 289 speex_bits_pack(&s->bits, 15, 5); 290 s->pkt_frame_count++; 291 } 292 } 293 294 /* write output if all frames for the packet have been encoded */ 295 if (s->pkt_frame_count == s->frames_per_packet) { 296 s->pkt_frame_count = 0; 297 if ((ret = ff_alloc_packet2(avctx, avpkt, speex_bits_nbytes(&s->bits))) < 0) 298 return ret; 299 ret = speex_bits_write(&s->bits, avpkt->data, avpkt->size); 300 speex_bits_reset(&s->bits); 301 302 /* Get the next frame pts/duration */ 303 ff_af_queue_remove(&s->afq, s->frames_per_packet * avctx->frame_size, 304 &avpkt->pts, &avpkt->duration); 305 306 avpkt->size = ret; 307 *got_packet_ptr = 1; 308 return 0; 309 } 310 return 0; 311} 312 313static av_cold int encode_close(AVCodecContext *avctx) 314{ 315 LibSpeexEncContext *s = avctx->priv_data; 316 317 speex_bits_destroy(&s->bits); 318 speex_encoder_destroy(s->enc_state); 319 320 ff_af_queue_close(&s->afq); 321 av_freep(&avctx->extradata); 322 323 return 0; 324} 325 326#define OFFSET(x) offsetof(LibSpeexEncContext, x) 327#define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM 328static const AVOption options[] = { 329 { "abr", "Use average bit rate", OFFSET(abr), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, 330 { "cbr_quality", "Set quality value (0 to 10) for CBR", OFFSET(cbr_quality), AV_OPT_TYPE_INT, { .i64 = 8 }, 0, 10, AE }, 331 { "frames_per_packet", "Number of frames to encode in each packet", OFFSET(frames_per_packet), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 8, AE }, 332 { "vad", "Voice Activity Detection", OFFSET(vad), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, 333 { "dtx", "Discontinuous Transmission", OFFSET(dtx), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, 334 { NULL }, 335}; 336 337static const AVClass speex_class = { 338 .class_name = "libspeex", 339 .item_name = av_default_item_name, 340 .option = options, 341 .version = LIBAVUTIL_VERSION_INT, 342}; 343 344static const AVCodecDefault defaults[] = { 345 { "b", "0" }, 346 { "compression_level", "3" }, 347 { NULL }, 348}; 349 350AVCodec ff_libspeex_encoder = { 351 .name = "libspeex", 352 .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"), 353 .type = AVMEDIA_TYPE_AUDIO, 354 .id = AV_CODEC_ID_SPEEX, 355 .priv_data_size = sizeof(LibSpeexEncContext), 356 .init = encode_init, 357 .encode2 = encode_frame, 358 .close = encode_close, 359 .capabilities = CODEC_CAP_DELAY, 360 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, 361 AV_SAMPLE_FMT_NONE }, 362 .channel_layouts = (const uint64_t[]){ AV_CH_LAYOUT_MONO, 363 AV_CH_LAYOUT_STEREO, 364 0 }, 365 .supported_samplerates = (const int[]){ 8000, 16000, 32000, 0 }, 366 .priv_class = &speex_class, 367 .defaults = defaults, 368}; 369