[mythtv-users] Myth playback is inefficient?

[Jonathan Rogers]

Dylan R. Semler wrote:
> I have always (since 18.1) had trouble playing HD content on my mythbox 
> from mythtv.  The specs for my combined frontend/backend are
> Dell 8200
> nvidia 4200 64 MB
> Pentium 4 2.23 GHz
> 512 MB RDRAM
> 
> Playing back a recorded HD file pauses every second or so with the 
> prebuffering pause messages in the frontend output.  However, /while/ 
> mythtv is trying to view the channel, I can play the channel file 
> (2101_20060515194118.mpg) with mplayer and it plays smoothly.  Both 
> mythtv and mplayer are not deinterlacing and they both use ALSA.  This 
> leads me to believe that there is something inherently inefficient about 
> the way mythtv tries to playback video.  Has this been noticed before?

I've certainly noticed that mythfrontend seems to use more CPU cycles
than mplayer does to play the same HD video stream. In my unscientific
experience, mplayer is almost always more frugal with CPU cycles than
other players. However, it also seems to me that mythfrontend produces
better quality playback by timing video frames more precisely and in
deinterlacing. It would be an interesting hack to add an alternate
playback mode that used mplayer in slave mode for more direct comparison.

Jonathan Rogers