[mythtv] Re: [mythtv-commits] mythtv commits

Isaac Richards ijr at po.cwru.edu
Fri Sep 19 16:41:26 EDT 2003


On Friday 19 September 2003 03:34 pm, Bruce Markey wrote:
> > How's things look on your machine with pvr-250 files and the 'extra audio
> > buffering' enabled, if you make it require fewer prebuffed frames?
>
> Pretty much the same any way I cut it.
<snip>
> I'm a little confused by the question so maybe I missed what
> you are looking for. The sleep that I changed in NVP determines
> how often it checks if EnoughPrebufferedFrames() is true. It is
> kPrebufferFrames that is the number of required prebuffed frames.
> Changing either of these seems to have very little impact on how
> long it takes for playback to start after a channel change.

I was just wondering, since turning on the 'extra audio buffering' setting 
should allow fewer frames to be prebuffered (ie, it allows stuff with the 
cle266 decoder -- only 4 video frames allowed, and xvmc -- only 8 video 
frames allowed, to play back without audio stuttering).  Figured it might 
help the software display case as well, if it'd allow us to drop down the 
required number of prebuffer frames.  But, since it doesn't really speed 
things up at all, ah well.

> The majority of the time is waiting for frames to show up in
> the vbuffers. Playback starts a relatively short time after the
> vbuffers start to fill. I'm guessing the biggest bottleneck is
> the wait for 256000 bytes to be encoded before the first
> WriteBlock can be sent.

Is it really waiting for that much to write?  I don't think it is..

Isaac


More information about the mythtv-dev mailing list