[FFmpeg-devel] FFMPEG extension OpenCL

madshi madshi at gmail.com
Sun Dec 11 11:51:36 CET 2011

2011/12/11 Reimar Döffinger <Reimar.Doeffinger at gmx.de>
> Well, just compare
> copy via PCIe, filter and scale up to 10x the size, display
> to
> filter and scale up to 10x the size, copy via PCIe, display

Ah, I see what you mean. Well, yes, if you use ffmpeg
this way, you're right. But there are multiple other scenarios,
e.g. if your renderer happens to use Direct3D9 instead of
OpenGL, which is the DirectShow default behaviour (and
AMD doesn't offer Direct3D9 <-> OpenCL interop), or
imagine you use the filters for reencoding instead of displaying.
But anyway, I get your point, and I agree that in your usage
scenario you could even save PCIe bandwidth.

> Uh, I consider the information theoretical approach
> a bit more simple. Scaling destroys information

Sorry, but that's just not true. Downscaling does destroy
information. But upscaling can actually improve things
(mainly it can reduce aliasing without losing any information),
if done right. Trust me there, I know what I'm talking about.
Anyway, I already see that we're opening up a can of worms
here, so probably we should just agree to disagree and
stop this discussion here. If you're interested in discussing
this further, I'm open for an email debate...  ;-)

Best regards, Mathias.

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