[MPlayer-users] Intelligent dynamic scaling.

[Baxter Kylie]

On 6/28/07, Reimar Doeffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> wrote:
> Hello,
> Note that downscaling is even worse than upscaling with many cards
> (heavy wandering staircase effect with small moving lines), so for
> getting best quality regardless of CPU usage this is not a good idea.
> And for everyone who uses -vo gl I'd like to hint at the yuv and lscale
> suboptions that enable higher quality scalers.
>
> Greetings,
> Reimar Doeffinger
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Reimar-

Great point re: downscaling. My display runs at native 720p and the
highest content I've seen are some hdtv channels that also run at 720p
so I wasn't thinking intelligently about the adverse effects of
downscaling a 1080p/i frame. The script has been adjusted. It still
issues a -vf-clr (with a video resolution > display size I assume
there isn't much of anything to be gained from heavy post-processing,
denoising, uniform noise, etc). If you don't like that behaviour,
though, feel free to change it at line 62.

re: opengl. I'm not familiar at all with how opengl handles fullscreen
and scaling. Nothing I had read about gl seemed to conclusively show
performance or quality superiority -- not to say I did a /load/ of
research on the subject... always open to be proven wrong. In any
case, if it handles it in the same way as xv/x11 then the scale
resolution issued as part of the filter chain (-vf scale=x:y) is
independent of the scaler choice (-sws 9). I am assuming you've set up
your preferred scaler in the default or alternate profiles and it
looks like this -lscale and -yuv are both issued the same. For
example, because I have the hardware for that type of chunking, I use
bicubic spline but such a choice is made outside of this script. It's
really just a dynamic way to choose a max scale resolution that won't
exceed display size while maintaining aspect ratio.

As always, comments, ideas, etc. Are appreciated. Adjusted script is included.

Regards,
~BK
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