[FFmpeg-user] Noise in audio stream during quiet periods

[Julian Pilfold-Bagwell]

 Hi All,


I'm trying to set up a tannoy system in our building using FFMPEG and
Icecast.  The server that is streaming is being fed from the 0db recording
output from an analogue amplifier that is wired up to an existing 100v
system and at the receiving end are PCs with active speakers fitted.

The problem that I have is that when there's no audio input to the tannoy,
there's a background noise that is intrusive enough to play out through the
speakers.  I've been trying to use the noise reduction features in FFMPEG
to reduce the noise but haven't managed to get rid of it.  The command I'm
running to run the system is:

/usr/bin/ffmpeg -f alsa -i hw:0,0 -acodec libmp3lame -ab 128k -ac 1
-content_type audio/mpeg -f mp3 icecast://source:<password-removed>@
172.20.0.75:8000/tannoy


Can anyone let me know if this is possible or if there's any way I could
implement something akin to a radio squelch that would just mute the output
when the input signal drops below a certain level.


Thanks in advance,


Jools