[mythtv-users] no sound for TV-related functions

[Bruce Markey]

David wrote:
> Hi All,
> 
> I've gotten (through a lot of suffering, but a lot of learning) my MythTV 
> box up-and-running.  DVD's work, the jukebox is a joy, and I can record, 
> playback, and pause live television.  The only problem is that sound 
> doesn't work for Live TV or recorded TV.  It's perfect with my 
> digital music, cds, and dvds.

Those are all playback only, of course, so your issues are
almost surely recording.

> Sound has been a lingering issue during this project as getting ALSA to 
> work was like pulling teeth.  However, I think everything else has been 
> resolved.  So here's where I stand.
> 
> Hardware:  BT878 tuner card
>            Via VT8233/A/8235/8237 Audio (onboard)
> 
> I have an internal cable running from the tuner's audio-out to the onboard 
> AUX-IN.

Perfect! I have a couple bttv cards with internal connectors.
I wish they all did.

>  I have another cable running from my DVD to the onboard CD-IN.  
> As I mentioned digital and CD sound work without a hitch.
> 
> I went to alsamixer and set "Line" to CAPTUR and muted it.

Not so perfect :-(. You said you plugged your bttv internal cable
into AUX-IN. Therefore, you want to mark AUX as the CAPTUR device
and mute it.

> I then found "Capture" and set it to CAPTUR and set its volume to 100%.

Good. Once you have it working you may find that you want to
turn it down from 100% to avoid distortion.

> I get no sound from the television.  If I unmute "Line," I get sound that 
> is out-of-sync with video, so I know that the pass-thru is working 

That doesn't make sense. Did you also use the external patch
cable to line in? Or is AUX unmuted and turned up so that it
is the actual source of the pass-thru sound?

> I'm able to load the btaudio modules, but there is no change in sound.  

The btaudio module will always load but that doesn't mean the
card has an onboard DSP. Even for the few that do, I believe
using a soundcard is the better solution anyway and btaudio
should only be used if there isn't a PCI slot for a soundcard.

--  bjm