[mythtv-users] PVR-350 TVout and no ALSA sound

Fedor Pikus fpikus at gmail.com
Thu Jun 30 19:07:31 UTC 2005

On 6/30/05, Nick <knowledgejunkie at gmail.com> wrote:
> On 6/30/05, Fedor Pikus <fpikus at gmail.com> wrote:
> > I tried to change my Myth box to output TV using PRV350 TV-out instead
> > of NVidia TVout.
> > It works, except for this:
> >
> > As soon as I enable "Use PVR-350 MPEG2 decoder" in front-end, I don't
> > get audio in MythTV. When MythTV starts, it says "Unable to initialize
> > ALSA". In mythfrontend log, I get this message:
> >
> > Opening audio device 'default'.
> > Rate doesn't match (requested 0Hz, got 4000Hz)
> > Unable to set ALSA parameters
> > Using the PVR-350 decoder/TV-out
> >
> > If I uncheck "Use PVR-350" and do NO OTHER CHANGES, MythTV initialized
> > ALSA and plays sound just fine. I did not check "use PVR350 for audio"
> > checkbox (if I do, I get no error message but no sound either, of
> > course, since PVR350 audio outs are not connected to anything).
> >
> > In either case, MythMusic can play music with no problems. Mplayer can
> > play to -ao alsa, so playing videos and DVDs also works. It's only
> > MythTV that is affected, both for live TV and recording playback.
> I thought that if you used the PVR-350's decoder, you couldn't choose
> which parts of the stream it decodes (that's probably changed in the
> latest release). Therefore, if you choose to use the decoder, it will
> decode audio and video, not using the soundcard at all. Using
> different devices for the streams could also introduce sync issues
> which would need to be fixed.

The comment for "use PVR350 audio" checkbox seem to imply otherwise:
it says that the common way to route audio is to your regular audio
card, but if you really want to use PVR350  for both audio and video,
check this box.

> The common way to set this up is to use a Y-cable to connect the 350
> audio outs to the line-in of the soundcard. Select the line-in as the
> recording source, set it to a sensible leve, mute it, and then
> everything should work.
> I'd also investigate why you don't get sound when you choose to use
> the 350 to decode the audio. The lack of errors mean it is likely a
> source is muted (but working).

I don't get any sound because I did not connect PVR350 audio outs, at
the very least (it may be muted too, but it seems irrelevant so far).
I don't really want to add another digital-analog-digital conversion
to my sound (in the end, it would have to come out of Audigy SPDIF)

> Nick

Fedor G Pikus (fpikus at gmail.com)

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