I had problem with hdmi audio from ubuntu. Video is going fine to LCD tv through HDMI cable, but no audio.
Not sure if that is a problem with operating system or the multimedia softwares, but I found mplayer supporting audio as well.
Following line has fixed hdmi audio for me.
mplayer -afm hwac3,hwdts, -ao alsa:device=hdmi -channels 2 file
Skype, web cam:
Web cam was not detected by skype on ubuntu (9.04). After searching on internet, installed gspcs-source, followed by a system restart.
sudo apt-get install gspca-source
Skype recognized my webcam and when ever I am on voice call with my skype contacts, I am able to share video through webcam.
Kopete, yahoo IM problem:
Kopete was not able to connect to Yahoo server. fix I found on internet is add subdomain "cn" in the server name (account preferences). this "cn.scs.msg.yahoo.com" one worked for me. the default port of 5050 is same.
kopete is not able to detect webcam. It needs jasper conversion utility installed. I tried to to install libjasper-progs, but it seems replaced by another one in the ubuntu repository.
Here is the line that worked for me.
sudo apt-get install libjasper-runtime