From 978d5bd2a7d803ed5ebfe29600811555db4f632b Mon Sep 17 00:00:00 2001 From: Dmitry Samonenko Date: Fri, 5 Oct 2012 00:36:16 +0400 Subject: libspeexenc: Add an option for enabling DTX MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Discontinuous transmission is an addition to VAD/VBR operation, that allows to greatly reduce bitrate for silent chunks or stationary noises. Signed-off-by: Martin Storsjö --- libavcodec/libspeexenc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'libavcodec/libspeexenc.c') diff --git a/libavcodec/libspeexenc.c b/libavcodec/libspeexenc.c index 43f84dc5f4..5a5079b43c 100644 --- a/libavcodec/libspeexenc.c +++ b/libavcodec/libspeexenc.c @@ -85,6 +85,7 @@ typedef struct { 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; @@ -120,6 +121,7 @@ static av_cold void print_enc_params(AVCodecContext *avctx, 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) @@ -196,6 +198,13 @@ static av_cold int encode_init(AVCodecContext *avctx) if (s->vad) speex_encoder_ctl(s->enc_state, SPEEX_SET_VAD, &s->vad); + /* Activiting 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); @@ -318,6 +327,7 @@ static const AVOption options[] = { { "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 }, }; -- cgit v1.2.1 From f1c6a740fcb9ea0a977855bb708c0541149fa9cf Mon Sep 17 00:00:00 2001 From: Dmitry Samonenko Date: Fri, 5 Oct 2012 00:42:31 +0400 Subject: libspeexenc: Updated commentary to reflect recent changes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Martin Storsjö --- libavcodec/libspeexenc.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'libavcodec/libspeexenc.c') diff --git a/libavcodec/libspeexenc.c b/libavcodec/libspeexenc.c index 5a5079b43c..cbfa5be92b 100644 --- a/libavcodec/libspeexenc.c +++ b/libavcodec/libspeexenc.c @@ -62,6 +62,23 @@ * 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 -- cgit v1.2.1