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Libspeex VAD support

Option for Voice Activity Detection is added to speex encoder.

Speex detects non-speech periods and encodes them with just enough bits
to reproduce the background noise, aka ``comfort noise generation''.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Dmitry Samonenko 2012-09-29 15:47:28 +04:00 committed by Michael Niedermayer
parent 44ae7badae
commit c785b6db73

View File

@ -75,6 +75,7 @@
#include "internal.h"
#include "audio_frame_queue.h"
/* TODO: Think about converting abr, vad, dtx (still to come) and such flags to a bit field */
typedef struct {
AVClass *class; ///< AVClass for private options
SpeexBits bits; ///< libspeex bitwriter context
@ -84,6 +85,7 @@ typedef struct {
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 pkt_frame_count; ///< frame count for the current packet
AudioFrameQueue afq; ///< frame queue
} LibSpeexEncContext;
@ -118,6 +120,7 @@ static av_cold void print_enc_params(AVCodecContext *avctx,
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);
}
static av_cold int encode_init(AVCodecContext *avctx)
@ -158,6 +161,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
if (avctx->flags & 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);
@ -189,6 +193,10 @@ static av_cold int encode_init(AVCodecContext *avctx)
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);
/* set encoding complexity */
if (avctx->compression_level > FF_COMPRESSION_DEFAULT) {
complexity = av_clip(avctx->compression_level, 0, 10);
@ -308,6 +316,7 @@ 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 },
{ NULL },
};