I'm trying to track down the cause of occasional periods of silence that are happening with my Airtime installation. One thing I've picked up in the logs (ls_script.log) are these: "2013/11/07 19:13:05 [alsa_out(default):2] Underrun!" that seem to coincide with the start or end of every track. Is it something to worry about? Other threads mentioning it asked about whether the installation is a virtual server; it is a VM on an ESXi box, with two cores and 1GB of ram.
I'm have ALSA output enabled, as well as one stream configured, connecting to the local icecast server. When I set the stream to mp3, CPU usage sits at 40%, when I disable it or set it to ogg, CPU usage sits at 17%. When the stream is disabled, the "Underrun!" messages stop.
edit: Changing from ALSA to OA drops liquidsoap cpu usage to 8%, but breaks it in VLC for some reason (large gaps) whether it's mp3 or ogg.
So is there some issue with encoding streams in mp3, or are these unrelated symptoms?