/* * Copyright (C) 2009 Justin Ruggles * Copyright (c) 2009 Xuggle Incorporated * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * libspeex Speex audio encoder * * Usage Guide * This explains the values that need to be set prior to initialization in * order to control various encoding parameters. * * Channels * Speex only supports mono or stereo, so avctx->channels must be set to * 1 or 2. * * Sample Rate / Encoding Mode * Speex has 3 modes, each of which uses a specific sample rate. * narrowband : 8 kHz * wideband : 16 kHz * ultra-wideband : 32 kHz * avctx->sample_rate must be set to one of these 3 values. This will be * used to set the encoding mode. * * Rate Control * VBR mode is turned on by setting AV_CODEC_FLAG_QSCALE in avctx->flags. * avctx->global_quality is used to set the encoding quality. * For CBR mode, avctx->bit_rate can be used to set the constant bitrate. * Alternatively, the 'cbr_quality' option can be set from 0 to 10 to set * a constant bitrate based on quality. * For ABR mode, set avctx->bit_rate and set the 'abr' option to 1. * Approx. Bitrate Range: * narrowband : 2400 - 25600 bps * wideband : 4000 - 43200 bps * ultra-wideband : 4400 - 45200 bps * * Complexity * Encoding complexity is controlled by setting avctx->compression_level. * The valid range is 0 to 10. A higher setting gives generally better * quality at the expense of encoding speed. This does not affect the * bit rate. * * Frames-per-Packet * The encoder defaults to using 1 frame-per-packet. However, it is * sometimes desirable to use multiple frames-per-packet to reduce the * amount of container overhead. This can be done by setting the * 'frames_per_packet' option to a value 1 to 8. * * * Optional features * Speex encoder supports several optional features, which can be useful * for some conditions. * * Voice Activity Detection * When enabled, voice activity detection detects whether the audio * being encoded is speech or silence/background noise. VAD is always * implicitly activated when encoding in VBR, so the option is only useful * in non-VBR operation. In this case, Speex detects non-speech periods and * encodes them with just enough bits to reproduce the background noise. * * Discontinuous Transmission (DTX) * DTX is an addition to VAD/VBR operation, that allows to stop transmitting * completely when the background noise is stationary. * In file-based operation only 5 bits are used for such frames. */ #include #include #include #include "libavutil/channel_layout.h" #include "libavutil/common.h" #include "libavutil/opt.h" #include "avcodec.h" #include "internal.h" #include "audio_frame_queue.h" typedef struct LibSpeexEncContext { AVClass *class; ///< AVClass for private options SpeexBits bits; ///< libspeex bitwriter context SpeexHeader header; ///< libspeex header struct void *enc_state; ///< libspeex encoder state int frames_per_packet; ///< number of frames to encode in each packet float vbr_quality; ///< VBR quality 0.0 to 10.0 int cbr_quality; ///< CBR quality 0 to 10 int abr; ///< flag to enable ABR int vad; ///< flag to enable VAD int dtx; ///< flag to enable DTX int pkt_frame_count; ///< frame count for the current packet AudioFrameQueue afq; ///< frame queue } LibSpeexEncContext; static av_cold void print_enc_params(AVCodecContext *avctx, LibSpeexEncContext *s) { const char *mode_str = "unknown"; av_log(avctx, AV_LOG_DEBUG, "channels: %d\n", avctx->channels); switch (s->header.mode) { case SPEEX_MODEID_NB: mode_str = "narrowband"; break; case SPEEX_MODEID_WB: mode_str = "wideband"; break; case SPEEX_MODEID_UWB: mode_str = "ultra-wideband"; break; } av_log(avctx, AV_LOG_DEBUG, "mode: %s\n", mode_str); if (s->header.vbr) { av_log(avctx, AV_LOG_DEBUG, "rate control: VBR\n"); av_log(avctx, AV_LOG_DEBUG, " quality: %f\n", s->vbr_quality); } else if (s->abr) { av_log(avctx, AV_LOG_DEBUG, "rate control: ABR\n"); av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); } else { av_log(avctx, AV_LOG_DEBUG, "rate control: CBR\n"); av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); } av_log(avctx, AV_LOG_DEBUG, "complexity: %d\n", avctx->compression_level); av_log(avctx, AV_LOG_DEBUG, "frame size: %d samples\n", avctx->frame_size); av_log(avctx, AV_LOG_DEBUG, "frames per packet: %d\n", s->frames_per_packet); av_log(avctx, AV_LOG_DEBUG, "packet size: %d\n", avctx->frame_size * s->frames_per_packet); av_log(avctx, AV_LOG_DEBUG, "voice activity detection: %d\n", s->vad); av_log(avctx, AV_LOG_DEBUG, "discontinuous transmission: %d\n", s->dtx); } static av_cold int encode_init(AVCodecContext *avctx) { LibSpeexEncContext *s = avctx->priv_data; const SpeexMode *mode; uint8_t *header_data; int header_size; int32_t complexity; /* channels */ if (avctx->channels < 1 || avctx->channels > 2) { av_log(avctx, AV_LOG_ERROR, "Invalid channels (%d). Only stereo and " "mono are supported\n", avctx->channels); return AVERROR(EINVAL); } /* sample rate and encoding mode */ switch (avctx->sample_rate) { case 8000: mode = &speex_nb_mode; break; case 16000: mode = &speex_wb_mode; break; case 32000: mode = &speex_uwb_mode; break; default: av_log(avctx, AV_LOG_ERROR, "Sample rate of %d Hz is not supported. " "Resample to 8, 16, or 32 kHz.\n", avctx->sample_rate); return AVERROR(EINVAL); } /* initialize libspeex */ s->enc_state = speex_encoder_init(mode); if (!s->enc_state) { av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex\n"); return -1; } speex_init_header(&s->header, avctx->sample_rate, avctx->channels, mode); /* rate control method and parameters */ if (avctx->flags & AV_CODEC_FLAG_QSCALE) { /* VBR */ s->header.vbr = 1; s->vad = 1; /* VAD is always implicitly activated for VBR */ speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR, &s->header.vbr); s->vbr_quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA, 0.0f, 10.0f); speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR_QUALITY, &s->vbr_quality); } else { s->header.bitrate = avctx->bit_rate; if (avctx->bit_rate > 0) { /* CBR or ABR by bitrate */ if (s->abr) { speex_encoder_ctl(s->enc_state, SPEEX_SET_ABR, &s->header.bitrate); speex_encoder_ctl(s->enc_state, SPEEX_GET_ABR, &s->header.bitrate); } else { speex_encoder_ctl(s->enc_state, SPEEX_SET_BITRATE, &s->header.bitrate); speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, &s->header.bitrate); } } else { /* CBR by quality */ speex_encoder_ctl(s->enc_state, SPEEX_SET_QUALITY, &s->cbr_quality); speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, &s->header.bitrate); } /* stereo side information adds about 800 bps to the base bitrate */ /* TODO: this should be calculated exactly */ avctx->bit_rate = s->header.bitrate + (avctx->channels == 2 ? 800 : 0); } /* VAD is activated with VBR or can be turned on by itself */ if (s->vad) speex_encoder_ctl(s->enc_state, SPEEX_SET_VAD, &s->vad); /* Activating Discontinuous Transmission */ if (s->dtx) { speex_encoder_ctl(s->enc_state, SPEEX_SET_DTX, &s->dtx); if (!(s->abr || s->vad || s->header.vbr)) av_log(avctx, AV_LOG_WARNING, "DTX is not much of use without ABR, VAD or VBR\n"); } /* set encoding complexity */ if (avctx->compression_level > FF_COMPRESSION_DEFAULT) { complexity = av_clip(avctx->compression_level, 0, 10); speex_encoder_ctl(s->enc_state, SPEEX_SET_COMPLEXITY, &complexity); } speex_encoder_ctl(s->enc_state, SPEEX_GET_COMPLEXITY, &complexity); avctx->compression_level = complexity; /* set packet size */ avctx->frame_size = s->header.frame_size; s->header.frames_per_packet = s->frames_per_packet; /* set encoding delay */ speex_encoder_ctl(s->enc_state, SPEEX_GET_LOOKAHEAD, &avctx->initial_padding); ff_af_queue_init(avctx, &s->afq); /* create header packet bytes from header struct */ /* note: libspeex allocates the memory for header_data, which is freed below with speex_header_free() */ header_data = speex_header_to_packet(&s->header, &header_size); /* allocate extradata */ avctx->extradata = av_malloc(header_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!avctx->extradata) { speex_header_free(header_data); speex_encoder_destroy(s->enc_state); av_log(avctx, AV_LOG_ERROR, "memory allocation error\n"); return AVERROR(ENOMEM); } /* copy header packet to extradata */ memcpy(avctx->extradata, header_data, header_size); avctx->extradata_size = header_size; speex_header_free(header_data); /* init libspeex bitwriter */ speex_bits_init(&s->bits); print_enc_params(avctx, s); return 0; } static int encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr) { LibSpeexEncContext *s = avctx->priv_data; int16_t *samples = frame ? (int16_t *)frame->data[0] : NULL; int ret; if (samples) { /* encode Speex frame */ if (avctx->channels == 2) speex_encode_stereo_int(samples, s->header.frame_size, &s->bits); speex_encode_int(s->enc_state, samples, &s->bits); s->pkt_frame_count++; if ((ret = ff_af_queue_add(&s->afq, frame)) < 0) return ret; } else { /* handle end-of-stream */ if (!s->pkt_frame_count) return 0; /* add extra terminator codes for unused frames in last packet */ while (s->pkt_frame_count < s->frames_per_packet) { speex_bits_pack(&s->bits, 15, 5); s->pkt_frame_count++; } } /* write output if all frames for the packet have been encoded */ if (s->pkt_frame_count == s->frames_per_packet) { s->pkt_frame_count = 0; if ((ret = ff_alloc_packet(avpkt, speex_bits_nbytes(&s->bits)))) { av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n"); return ret; } ret = speex_bits_write(&s->bits, avpkt->data, avpkt->size); speex_bits_reset(&s->bits); /* Get the next frame pts/duration */ ff_af_queue_remove(&s->afq, s->frames_per_packet * avctx->frame_size, &avpkt->pts, &avpkt->duration); avpkt->size = ret; *got_packet_ptr = 1; return 0; } return 0; } static av_cold int encode_close(AVCodecContext *avctx) { LibSpeexEncContext *s = avctx->priv_data; speex_bits_destroy(&s->bits); speex_encoder_destroy(s->enc_state); ff_af_queue_close(&s->afq); av_freep(&avctx->extradata); return 0; } #define OFFSET(x) offsetof(LibSpeexEncContext, x) #define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM static const AVOption options[] = { { "abr", "Use average bit rate", OFFSET(abr), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, { "cbr_quality", "Set quality value (0 to 10) for CBR", OFFSET(cbr_quality), AV_OPT_TYPE_INT, { .i64 = 8 }, 0, 10, AE }, { "frames_per_packet", "Number of frames to encode in each packet", OFFSET(frames_per_packet), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 8, AE }, { "vad", "Voice Activity Detection", OFFSET(vad), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, { "dtx", "Discontinuous Transmission", OFFSET(dtx), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, { NULL }, }; static const AVClass class = { .class_name = "libspeex", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; static const AVCodecDefault defaults[] = { { "b", "0" }, { "compression_level", "3" }, { NULL }, }; AVCodec ff_libspeex_encoder = { .name = "libspeex", .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_SPEEX, .priv_data_size = sizeof(LibSpeexEncContext), .init = encode_init, .encode2 = encode_frame, .close = encode_close, .capabilities = AV_CODEC_CAP_DELAY, .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE }, .channel_layouts = (const uint64_t[]){ AV_CH_LAYOUT_MONO, AV_CH_LAYOUT_STEREO, 0 }, .supported_samplerates = (const int[]){ 8000, 16000, 32000, 0 }, .priv_class = &class, .defaults = defaults, };