[FFmpeg-user] OpenCL? What Effect Does It Have

[Tom Evans]

On Tue, Aug 6, 2013 at 2:02 PM, James Board <jpboard2 at yahoo.com> wrote:
> OpenCL is an API for using GPUs to do computationally
> intensive tasks.  See this URL
>     http://en.wikipedia.org/wiki/OpenCL
> By coding expensiev tasks in OpenCL, especially image processing operations
> which ffmpeg does all the time, you can achieve 10x to 100x performance
> improvement.  I'd like to know what parts of ffmpeg have been
> accelerated with OpenCL.  This could potentially improve the
> performance and prestige of ffmpeg.  But it doesn't sound like much
> work has been done in this area.  Is that true?

OpenCL can be used to accelerate the unsharp and deshake filters, as
documented in the filters documentation.

https://www.ffmpeg.org/ffmpeg-filters.html

Sometimes it gives worse results than using the CPU:

http://ffmpeg.zeranoe.com/forum/viewtopic.php?f=10&t=1284

Generally the consensus (at least on here, as far as I can tell) is
that GPU assisted encoding is slow and gives crap results. YMMV.

Cheers

Tom