[Libva] Is there a limit on number of parallel encoders?

[Zhao, Yakui]

On Wed, 2014-05-28 at 04:34 -0600, Torbjorn tyridal wrote:
> I have the following case on a haswell 4770R  (gigabyte brix)
> 
> A libva based encoder reads raw 1920x1088 nv12 frames from file on
> ramfs. Encoding set to 10 slices, fixed qp (26). cpu governor set to
> performance.
> 
> if I run two of the above in parallel, each goes along at 230fps, 18%
> cpu (top). ie a total of 460 fps/36% cpu
> If I then add a third instance the frame rate drops to 72fps (total 216)
> and the cpu load jumps to 86 / 198%.
> 
> Is there an explanation for the above in libva? 

How about the configuration on your machines? For example: cpuinfo
(cat /proc/meminfo) and meminfo (cat /proc/meminfo).

How about the test result if the encode reads the frame from the file on
harddisk directly?

Thanks.
    Yakui

> 
> Decoder scales nicely: 1 * 926 fps, 2 * 626 fps, 3 * 411 fps, 4 * 288
> fps, 5 * 229 fps ...
> 
> 
> Cheers, T.
>