[mythtv-users] Re: Need advice with 'Pixelization"

[Larry K]

OK, I went into mythfrontend -> Settings -> TV settings -> Playback, and 
added the Bob 2x Deinterlace option, as well as the "Use video as Timebase" 
option. This seemed to correct the artifacts that I was seeing, both in live 
TV, and in peviously recorded material. Based ont his, can I assume that the 
artifacts were there becasue of the way the encoded video was being decoded 
for display? As opposed to it being a flaw in the way the PVR-250 was 
encoding the video in the first place? 

I went on to experiment further with the XvMC hardware decoding, and that 
seemed to introduce stutter. I noticed that the CPU consumption of 
mythfrontend dropped by 50% when I did this. Based on this, I assume that 
when this box is not checked, myth is doing XvMC software decoding instead? 
So, one way or the other, XvMC decoding is being done? 

I did not try libmpeg2 or XV. I gather that XV and XvMC are mutually 
exclusive options. Is that correct? And what about libmpeg2? Is that to be 
used in combination with either XV or XvMC? I guess at some point, it will 
become increasingly difficult to discern any improvement, as the picture 
quality gets closer to nirvana.

On 4/14/05, Will Dormann <wd at pobox.com> wrote:
> 
> Larry K wrote:
> > I'll bet that's my problem, then. FWIW, my recordings are 2.2GB/hour,
> > which seems pretty reasonable.
> >
> > I'll try the Bob Deinterlacing when I get home. Thanks! This forum 
> rocks! 
> 
> For the best quality TV-out:
> 
> - Make sure MythTV is compiled with OpenGL Vsync support (Otherwise Bob
> won't look smooth)
> - Use a resolution of 800x600
> - Set Playback option to "Use Video as Timebase" 
> - Use Bob Deinterlacing
> 
> An earlier version of my tips are here:
> http://mythtv.info/moin.cgi/NVidiaMX4000HowTo
> 
> I'm planning on updating them to work with the recent builds. Probably 
> once 0.18 is released. The main difference is now it should be set to
> use XV instead of XvMC (XV has higher CPU usage, but is less "quirky")
> and also use libmpeg2 for decoding.
> 
> 
> -WD
>
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