[mythtv-users] Audio Buffer Underruns with XvMC and HD in 0.20

Steven Adeff adeffs.mythtv at gmail.com
Sat Sep 16 20:09:33 UTC 2006


On 9/16/06, Randall Blecher <randallb at gmail.com> wrote:
>
> I was using the Debian packages from debian-multimedia.org.  I also tried
> compiling mythtv from the Debian packages' source and then today I tried
> compiling mythtv from the SVN version.  All three versions of the frontend
> have the same problem.
>
> >
> >
> >
> > I'm using XvMC with OpenGL Vsync and CPU usage is generally in the 60-90%
> range when viewing HD material (this is normal for me).   There doesn't seem
> to be any CPU spike when I get the WriteAudio underruns.  And I also have
> the Extra Audio buffering enables.  No deinterlace either.
>
>
> I also tried using OpenGL Vsync, but that doesn't seem to have any effect
> either.  My CPU is usually 40-60%.
>
> It does seem to vary depending on the channel.  CBS and NBC seem to have
> much less frequent underruns than FOX (I only tested this for about 15
> minutes though).  But a recording from FOX that played fine with 0.19
> produces the underruns with 0.20.

of note, CBS & NBC are 1080i, FOX is 720p. Perhaps it has something to
do with your choice in deinterlace algorithm? Make sure you are using
Bob or Onefield, and perhaps trying both (or neither if you have
OpenGL Vsync enabled).

-- 
Steve
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