[FFmpeg-devel] [PATCH 3/3][RFC] avfilter/vf_chromakey: Add OpenCL acceleration

Wei Gao highgod0401 at gmail.com
Wed Oct 14 03:40:17 CEST 2015

2015-10-13 18:27 GMT+08:00 Timo Rothenpieler <timo at rothenpieler.org>:

> Hi
>> I use your filter, but the kernel can't pass the compile, you should
>> consider the "double" type in the kernel, some GPU card does not support
>> double type
>> I add "#pragma OPENCL_EXTENSION cl_khr_fp64: enable " to the kernel, but
>> it does not works
>> I will check the error tomorrow
> I tested this filter on Nvidia on Linux, using driver 355 and on the Intel
> CPU-based OpenCL SDK so far.
> Using floats potentially has an impact on the keying quality.

I have check the error, for some card, yes, just like what I said above,
some cards does not support double type, so we must check the opencl
extension: cl_khr_fp64 before the kernel compile. If the device support, we
use GPU, else, we use CPU or use float type, Is it OK?

Best regards

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