[x264-devel] [OpenCL] Please whitelist mesa's OpenCL implementation

[BugMaster]

On Thu, 13 Feb 2014 16:09:49 +0100, Niccolò Belli wrote:
> Hi,
> I'm using Gentoo Linux amd64 with latest graphic stack from git (mesa 
> git, llvm git, linux 3.14, etc.) and x264 git. My graphic card is an AMD
> Radeon HD 7950.

> Test file (~90s/~200MB): 
> https://mega.co.nz/#!eQhSjJQR!EEe8-taN5IspIu-RW0WQzmvKzc5fkCn282kS5ugZ_as

> ffmpeg -i PlanetEarthBirds.mkv -c:v libx264 -preset slower -crf 18 
> -x264opts opencl -c:a copy slower-cfr18-ocl.mkv

> This is what I get when encoding with --opencl with Catalyst 14.1_beta:

> [libx264 @ 0x257e360] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
> [libx264 @ 0x257e360] OpenCL acceleration enabled with Advanced Micro 
> Devices, Inc. Tahiti (SI)

> Unfortunately when I use mesa's OpenCL implementation I get:

> [libx264 @ 0x1409360] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
> [libx264 @ 0x1409360] OpenCL: Unable to find a compatible device


> Is it possible to whitelist mesa's OpenCL implementation? Can someone 
> please write a patch to force-enable OpenCL so that I can at least test
> if it works with mesa?

> Thanks,
> Niccolò

Hi. Most likely mesa's OpenCL implementation doesn't support one of
the 2d image formats needed. x264 need that OpenCL implementation
supported CL_R : CL_UNSIGNED_INT32 and CL_RGBA : CL_UNSIGNED_INT8.
You can try to run x264 with verbose/debug level of loging to find out
if this the case or try to specify --opencl-device 0.