[mythtv] Analog (v4l) tuner card audio sample rate
Michael T. Dean
mtdean at thirdcontact.com
Sun Feb 25 18:22:25 UTC 2007
On 02/24/2007 04:25 PM, Ed Winde (mythtv-dev) wrote:
>
> I'm trying to setup a Kworld ATSC-110 (hybrid) DVB/analog tuner card
> under mythtv After building from the subversion source, mythtv-setup
> allows me to configure both halves (digital and analog) of the card.
> (Yea!)
>
> The digital portion of the cards is working well - but tuning to an
> analog channel gives me "stuttering chipmunk" sound - a cycle of a
> second or two of audio played too fast, followed by a second or two of
> silence. The console reports "prebuffering pause" and audio
> underruns. My interpretation is that the tuner card and myth aren't
> agreeing on the audio sampling rate.
>
> One of the mythtv-setup options for the analog portion of the card is
> "audio sampling rate limit". I've set that to 32000 - but I don't see
> any change with that limit set. I also played with the audio sampling
> rate in the "LiveTV" recording profile, and had brief success, but
> that no longer seems to work.
>
> My understanding of the "audio sampling rate limit" is that it
> indicates the highest rate at which the card can provide audio
> samples. If this is correct, it should override the sampling rate set
> in the recording profiles. (True?) If so, something isn't working.
> If someone could point me towards the right section in the code, I'd
> be happy to investigate further.
I think you're going the wrong way. You need to set the sampling rate
to 48kHz (or fix your ALSA configuration). It's playback--not
recording--where there's "disagreement".
Mike
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