[mythtv-users] What does the mythtv-vid branch and OpenGL renderer have to offer

Stroller linux.luser at myrealbox.com
Thu Feb 8 04:10:53 UTC 2007

On 8 Feb 2007, at 02:20, Daniel Kristjansson wrote:
>>>> What is the purpose of the mytht-vid branch??
>> Presumably the plan is for this work to be folded back into the main
>> tree at some point in the future?

Whilst I've got your attention, any comment on this?

I'd hate to get used to the features offered by the mytht-vid branch,  
only to find them removed when I upgrade to 0.21 (or whatever).

>> Is it not possible at present to display "standard def sources at
>> 1080p in realtime", or are you referring to extra-quality  
>> upscaling &/
>> or the constraints of your hardware?
> You can display these quite easily using the XVideo and XvMC
> playback methods; I've been doing it for about 3 years now.
> The problem is that the new OpenGL replacement for XVideo has
> not yet been fully optimized so if you choose to use that
> video output method you might get some stuttering.

Thanks for your most helpful reply.

> ... One of the the things the mythtv-vid branch gives you
> is a choice in how to handle different types of video, so
> you can use a high quality scaler for SDTV, ...

Am I right in thinking the high quality scaler for SDTV will give a  
better picture than just "playing back" an SD source on a HD display?  
I have heard recently of enthusiasts buying "upscaling DVD players"  
which are supposed to give better IQ on a high-def telly than a  
regular DVD player. Is this the difference between the mytht-vid  
branch & regular Myth?

> ... but skip that
> HQ scaling step when outputting HDTV since you don't need it.
> The means that you can get the best quality/performance
> trade-off for each video type.

I would have thought that skipping the scaling would be "obvious"  
when playing back HD material on an HD display, but perhaps your  
words imply that an additional level of filtering / digital  
processing is applied to SD sources after they've been scaled up? (in  
the mytht-vid branch, I mean?) I guess this would the the way to  
remove or smooth jaggies?

Thanks for your tolerance of my ignorance,


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