btaudio is a kernel module for reading the audio directly from Brook Tree bttv supported TV-cards. This may or may not work on your TV-card depending on chipset and used features by the card manufacturer. Give it a try if you want.
I'm using Gentoo, so this will be a little strange to some. :)
To get btaudio working with my ATI TV Wonder, I put the following lines into /etc/modules.d/bttv.
alias sound-slot-1 btaudio alias sound-service-1-0 btaudio
I also added btaudio to my /etc/modules.autoload/kernel-2.6.
I then ran
For a Fedora setup I had on another machine, I added the following lines to my /etc/modules.conf.
alias sound-slot-1 btaudio alias sound-service-1-0 btaudio pre-install btaudio modprobe via82cxxx_audio
The pre-install line makes sure that the sound card driver is loaded before the btaudio, so that btaudio will always get /dev/dsp1 and /dev/dsp2.
I also loaded the btaudio module from the /etc/rc.d/rc.local file with following command.
In MythTV, I setup my device /dev/video0 with /dev/dsp1 for the sound, and it just works!
For auto-loading by Alsa, you can do the following:
alias snd-btaudio btaudio alias sound-slot-1 snd-btaudio alias sound-service-1-0 snd-btaudio
Alsa basically just looks for anything beginning with "snd-", and I really didn't want to load btaudio using rc.local. This works great for me and gives me status on boot-up through Alsa.