[mythtv] Alsa capture support

Matthew Wire devel at mrwire.co.uk
Thu Aug 24 10:58:14 UTC 2006


> Well, I for one have always used v4lctl to unmute and set the volume for my 
> SAA7134 cards, OSS or ALSA. I also make sure (in the case of saa7134-alsa) to 
> set 'video' to the recording source and turn it up about 75-85%.
> 
> My v4lctl lines:
> 
> v4lctl -c /dev/video0 volume mute off
> v4lctl -c /dev/video0 volume 13
Well I didn't think I had the option of using v4lctl until I found that
I need to install xawtv-tools on ubuntu (edgy).
Sure enough, the problem is that my card is muted. Unmuting using v4lctl
works correctly.

> 
> MPlayer, TVtime, etc. unmute that setting while playing and then mutes it 
> again on exiting so if you use any other program to watch TV than MythTV 
> you'll need to unmute the volume yourself. At least that's my experience.
That seems to be correct
> 
> I haven't tried your arecord line yet, but it would certainly be interesting 
> if that works without unmuting the volume...
Unfortunately it won't.  Think I mislead you there, I was running
arecord with tvtime running so tvtime would have unmuted the card for
me.
At any rate, it seems to me that mythtv should probably be
muting/unmuting the card as necessary.  Can anyone point me to the right
place in the code to try and implement this?

I did have a go at writing alsa capture support and got to the stage
where it would make clicking sounds, but then got very muddled with
buffer sizes/periods etc. so that plan may have to sit on the back
burner for a while...

Matthew




More information about the mythtv-dev mailing list