[x264-devel] Bug (or bugs) in x264 rev 2334 OpenCL and one improvement proposal.

[Jason Garrett-Glaser]

On Wed, Jun 12, 2013 at 12:23 AM, Nihil <nihil at nihil.nu> wrote:
>>> So which leaves adding OpenCL support on -p 2 and -p 3.
>>
>>Multi-pass encoding performs the lookahead on the first pass; the
>>lookahead doesn't run on the second pass, so there would be nothing
>>for OpenCL to do.
>
> Well this is my bad, I wasn't expressing myself clearly. What my improvement
> proposal kept in it and what I was thinking but not explaining obviously is
> following.
>
> To expand OpenCL and GPU usage for all possible work areas not just
> lookahead. After all OpenCL & GPU's are used for Bitcoin mining, password
> cracking, in heavy industry for making strength assessment, in
> supercomputers etc. So in sense like SMP work would be divided between CPU
> and GPU where some of the frames are processed in CPU and others in GPU.

I'm confused; where is your proposal? Do you have a document
explaining how you intend to deal specifically with the
synchronization and parallelism problems inherent in GPU video
compression and interaction with an existing CPU encoder, as well as
restructuring or replacing all the various algorithms for which
efficient GPU implementation are impossible?

It is very easy to say that you want something extraordinary to happen
(e.g. "I want a billion dollars and a personal starship"), but on its
own not very useful without some kind of plan ("how I intend to earn a
billion dollars and build a personal starship").

Jason