Sunday, February 1, 2009

Ubuntu Intrepid, Skype, and Alsa Settings

I finally figured out the magic incantations to get skype working with Ubuntu Intrepid 8.10 and pulseaudio, at least on my hardware. I have 82801I (ICH9 Family) HD Audio Controller according to lshw and lspci. I have a microphone connected to the front mic input. The key was to ensure the alsa settings were correct. Here were the steps:

  1. Configure alsa using alsamixer, part of the Ubuntu alsa-utils package. I think there are also gui interfaces to do this. Here are some notes on settings:

    • In the 'recording' section (navigate with TAB), there are settings for both capture and capture 1. The key for me was to set capture to front mic. I think this has changed from Hardy. In Hardy, I had to set capture 1 to front mic. For good measure I set both to front mic.
    • The mic and mic boost settings didn't seem to affect anything on my system.
    • The front mic settings in 'playback' section apply to monitoring the mic input. A good initial sanity check is to bump up the front mic settings and make sure you hear the mic out of your speakers.

  2. Install the libasound2-plugins package. apt-cache show libasound2-plugins shows the version as 1.0.17-0ubuntu5 for me.
  3. Make sure the microphone works in pulseaudio. For this, the Ubuntu padevchooser package was handy. Run it and it adds a tray icon. I chose 'volume meter (recording)' from the drop-down menu. This basically invoked pavumeter with the right args to show the mic level that pulseaudio reads. At this point, when you tap your front mic, the vumeter window should show a bump in signal.
  4. Start skype (I think I use the one from the medibuntu repository) and go to options -> sound devices. There are three main settings:

    Sound in: pulse
    Sound out: pulse
    Ringing: pulse

    I set all to pulse, but my guess is that default is fine and defaults to pulse anyway.
    At this point the skype test call worked for me!