[FFmpeg-user] Problem with openCL

[99191957 at qq.com]

I'm a new user of ffmpeg. English is not my mother tongue, please don't mind that I'm quite pool in English..
I configed FFmpeg2.0 with “--enable-openCL ”. 
Can I use openCL to encode or decode a video---in oder to use GPU instead of CPU. If possible, how to do that. 
In user documetation, I found that: 
‘-opencl_options options (global)’
   options can be:
‘build_options’
‘platform_idx’
‘device_idx'
I cannot understand what does these options exact mean.
I'm wondering if anyone could help. 



99191957 at qq.com