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Diffstat (limited to 'libavcodec/libspeexenc.c')
| -rw-r--r-- | libavcodec/libspeexenc.c | 17 |
1 files changed, 17 insertions, 0 deletions
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 <speex/speex.h> |