[mythtv-users] What do I have to do to get HD working?

Michael T. Dean mtdean at thirdcontact.com
Fri Apr 14 21:49:52 UTC 2006


On 04/14/2006 05:36 PM, Kevin Kuphal wrote:
> Kevin Kuphal wrote:
>   
>> I'm about at my wits end.  I just purchased a P4 3.2ghz HT to do HDTV 
>> playback in software but no matter what I do, I get continual studdering 
>> and "Video X frames ahead of audio" on my HD playback material.  This 
>> happens on my MX4000 PCI video card system, my ATI 9100 IGP video card 
>> system, and my Unichrome Pro video card system. 
>>
>> Everything I read said that a P4 3.2 is enough to do HD but nothing I do 
>> can get it to work.  I'm running the 2.6.15 smp kernel but that almost 
>> seems to make it worse.  With the non-smp on my Unichrome system it 
>> plays back but only at about 17-20 fps.  With the smp kernel, it does 
>> the 29-30 but jumps and skips complaining about the video ahead of audio.
>>
>> Please, anyone have any help?
> And a little more, I can duplicate the 17-20fps setting when I set my 
> audio device to something wrong or if I disable audio in the BIOS.  Is 
> this possible some kind of ALSA problem maybe?
>   

Hmmm.  20fps is 2/3 of 30fps and 32kHz is 2/3 of 48kHz....  Perhaps your 
ALSA device is playing a 48kHz stream (which you're likely to see in 
HDTV) at 32kHz?

What audio device are you using for playback?  Assuming you have ALSA 
1.0.9 or above, try "ALSA:default", which will use the "plug" conversion 
plugin to automatically convert sample, rate, and format as required for 
your sound card.

Mike


More information about the mythtv-users mailing list