[FFmpeg-devel] FFMPEG extension OpenCL

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sat Dec 10 23:12:33 CET 2011

On 10 Dec 2011, at 22:51, madshi <madshi at gmail.com> wrote:
> 2011/12/10 Reimar Döffinger <Reimar.Doeffinger at gmx.de>
>> Deinterlace and possibly some high-quality scale filters.
> What kind of deinterlacing are you thinking about? E.g. yadif
> is already pretty fast when run on the CPU. I doubt that
> copying the video frames to GPU RAM, performing yadif
> there and then copying them back to System RAM would
> bring much of an improvement. Ok, one task worth
> considering would be motion compensated video
> deinterlacing.

Well, it depends on what the relative performance is.
However I think there is OpenCL/OpenGL interoperability that would mean no extra copying.
And lastly APUs that would not need copying were mentioned.
Particularly when CPU is busy decoding and also underpowered compared to the GPU as in AMD's that might be useful for yadif.

> High-quality scaling filters sounds like a good idea to me.
> Considering Lupescu's background in image processing,
> maybe also noise filtering and sharpening / detail
> enhancement?

Some scale filters can easily do these at the same time and I think they can give better results than separate scale and sharpening.

> One other area that comes to my mind is motion vector
> search to speed up video encoding. (Would also be needed
> for motion compensated video deinterlacing).

Those aren't really the same algorithms since they serve (slightly?) different purposes.
At least for video encoding I don't think there's reason to believe it will give any useful results.
Also x264 might be a more appropriate project for encoding, though they may be rather tired of most mentioning "GPU" and "encoding" disappearing rather quickly after actually trying to get something working.

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