[mythtv] [mythtv-commits] Ticket #2649: Opengl video renderer

[Mark Kendall]

On 1/24/07, Mark Buechler <mark.buechler at gmail.com> wrote:
> Mark, this patch looks very interesting indeed. I'd like to test it with my
> 5700, however, I'm not certain it's fast enough. I don't use any
> deinterlacers and I often watch 1080i content on a 1080i screen.
>
> In your estimation, what is the minimum NVidia card required for 1080i HD
> without any deinterlacers? Specifically, I'm interested in the OpenGL OSD.
>

Based on what I've seen and read, the main bottleneck with fragment
programs is texture sampling. yuv to rgb conversion takes 3 texture
samples per pixel per frame/field, yuv to rgba (for osd) takes 4 and
the most demanding deinterlacer takes another 11 (on top of yuv2rgb).

Some fag packet calculations suggest that the 6200 can cope with at
least 300,000,000 samples per second (standard def PAL, 50 fields per
second, progressive kernel deinterlacer) - probably more as it seems
to cope with pip on top as well.

Assuming PAL 1080i with opengl osd and no deinterlacers, the GPU will
need to do around 360million samples (around 435m for 30fps).

So my gut feeling would be that the 5700 can't cope (though I'm
guessing on its performance). Comment out 3 lines of code however and
you could force the main video to software color conversion and just
use hardware conversion for OSD....which might work.

I'll see if I can test that later (it was on my list of things to look
at anyway)

regards

Mark