How to stream mono using ffmpeg

[nasirq]

We are using Liquidsoap 2.1.2
And are unable to setup to stream mono. Any help is appreciated.

[rmens]

You might need to convert your stereo input to mono audio first. You can use the mean operator for that. For example:

stereoinput = single('/var/audio/hello.ogg')

make it mono:

monoaudio = mean(stereoinput)

And feed ffmpeg your monoaudio source.

[toots]

@rmens solution could work but we are also able to handle mono conversion at the encoder level. This should work:

s = ...

output.icecast(
  ...,
  %ffmpeg(format="mp3", %audio(codec="libmp3lame", channels=1),
  s
)