[mythtv] prebuffer audio related?

Steven mythmail at richardstraat.homedns.org
Thu Oct 28 08:12:20 UTC 2004


  > I still can't see what audio driver you are using?  Intel ICH is iffy
> for example

It's the audio chip onboard the ATI9100IGP chipset and it uses the 
atiixp alsa driver.
> 
> You appear to be recording at 44Khz.  Can you try recording at 48Khz and 
> see if this helps?
> 
> What are you using as an amp?  Is it spdif connected to an AV amp?  What 
> does the amp say about output rates?
> 
I have a Sony receiver connected with spdif and it says PCM 48 on the 
display when playback starts.
I was indeed recording at 32Khz (wich is the default MPEG2 settings I 
believe?) so I changed to 48Mhz and now the skips are less frequent and 
also less noticable.
2004-10-28 09:10:47 Changing from None to WatchingLiveTV
2004-10-28 09:11:51 prebuffering pause
2004-10-28 09:13:03 prebuffering pause
2004-10-28 09:15:03 prebuffering pause
2004-10-28 09:15:05 prebuffering pause
2004-10-28 09:23:14 prebuffering pause
2004-10-28 09:23:23 prebuffering pause
2004-10-28 09:24:55 prebuffering pause
2004-10-28 09:25:02 prebuffering pause
2004-10-28 09:26:24 prebuffering pause
2004-10-28 09:33:44 prebuffering pause


Using /dev/dsp Av sync is perfect. Using ALSA:spdif or ALSA:pcm.front 
audio is a little behind but no prebuffering pause at all.


> I'm thinking that there is some kind of resampling going on here, and 
> the audio driver is broken and not reporting free space correctly?
> 
Probably so.
But playing back the recordings with 32Khz audio in them with mplayer 
also gives me PCM 48 on my receivers display but the file plays fine.

> Ed W

Thanks for your help.

Steven


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