[mythtv] mythtv-vid branch needs testing

Daniel Burr dburr at veritel.com.au
Fri Aug 10 12:26:30 UTC 2007

On Thu, 2007-08-09 at 22:57 +0100, Andrew Lyon wrote:
> On 8/9/07, Matt <skd5aner at gmail.com> wrote:
>         On 8/9/07, Mark Kendall <mark.kendall at gmail.com> wrote:
>         > At some point in the next few months, I'll finish the code I
>         started
>         > for bicubic filtering which will be the first step towards
>         true 
>         > 'upscaling'. This is likely to require sifnificant gpu
>         horsepower
>         > though.
>         >
>         WHOO HOO!
> Is that multi threaded? I notice the core 2 quad 2.4ghz is good value,
> i can afford to upgrade my c2d 2.4 to that at least.. I want to anyway
> for when ffmpeg has multi threaded h.264 mbaff.

I don't believe that upscaling/filtering will parallelize very well because processing each line/block of output data requires accessing data from n lines above/below.  This is in contrast to decoding where each line/block can be processed in parallel because they are independent.

A hack could be to start one core processing from the beginning of the frame and the other from the end and let them meet up in the middle.

However, I believe this is all moot because Mark mentioned "GPU horsepower" implying that the filtering will be performed by the video card.  Have you considered using NVidia's Cg (http://developer.nvidia.com/page/cg_main.html) to implement it in vertex shaders?  I realise that it wouldn't be portable to VIA and Intel chips but it would seriously rock.


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