[mythtv-users] bttv audio (tvaudio) too load
papenfuss at juneau.me.vt.edu
papenfuss at juneau.me.vt.edu
Tue Nov 25 08:11:11 EST 2003
On Tue, 25 Nov 2003, Jelle Kalf wrote:
> --- cut ---
> The v4l bttv works OK, but the audio coming from it in mythtv is
> clipped badly. I first figured the mixer (SBlive), adjustments didn't help.
>
> I figured perhaps it was the stock OSS drivers, even with ALSA, no joy. I
> have since figured out that it's a v4lctl volume function causing the
> problem. If I decrease it with 'v4lctl volume 32768' (which is 50%), it's
> OK with xawtv, gv4l, etc. Mythtv resets this to something more like 80%,
> which clips the input to the soundcard. Any suggestions?
> --- /cut ---
>
> Ehm, in mythfrontend you can go to TV, Settings, recording profiles and set
> the input volume as far as I know ;)
>
> I think this might help you a lot.
>
I just looked again to make sure I wasn't insane, but there is no
option to set the input volume in the Settings/TV Settings/Recording profiles
section. The closest I've found is a gain control in
Settings/General/Audio, but it only changes the mixer volumes. The
volume that's causing the problem is the v4l low-level card setting, not the
mixer. In other words, putting *all* the mixer settings at something really
low like 10% doesn't fix the clipping. The input signal (output from the
capture card) is just too high.
Thoughts? Is this gain setting hardcoded in mythtv at compile-time? Just for
the record, the version I'm running of mythtv is vanilla rpm:
$ rpm -qa | grep myth
mythvideo-0.12-32.rh9.at
mythweb-0.12-36.rh9.at
mythnews-0.12-6.rh9.at
mythtv-backend-0.12-46.rh9.at
mythtv-theme-visor-0.20030711-1.rh9.at
mythdvd-0.12-14.rh9.at
mythmkmovie-1.0.1-3.rh9.at
mythweather-0.12-33.rh9.at
mythtv-suite-0.12-34.rh9.at
mythtv-0.12-46.rh9.at
mythgame-0.12-35.rh9.at
mythmusic-0.12-36.rh9.at
mythtv-theme-photo-4-4.rh9.at
libmyth-0.12-46.rh9.at
mythgallery-0.12-36.rh9.at
mythtv-theme-purplegalaxy-0.20030623-2.rh9.at
mythtv-frontend-0.12-46.rh9.at
Thanks though.... :)
-Cory
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