[FFmpeg-user] libvpx-vp9 not using all 4 real cores (no HT CPU) like libx264 does (in top: ~250% vs ~387%)

[Tom Evans]

On Wed, Nov 25, 2015 at 2:47 PM, D <dcmhoybdpzkh at web.de> wrote:
> Continuing and splitting up the problem which I have here:
> https://ffmpeg.org/pipermail/ffmpeg-user/2015-November/029274.html.
> The problem is that libx264 utilizes all 4 cores almost to the 400% ($ top),
> as it should be, but when using libvpx-vp9, it's only ~250%.
>
> $ cd ffmpeg-git-20151124-64bit-static
>
> No Problem:
> Almost 100% on all 4 cores if I use:
> $ ./ffmpeg -i a.mp4 -c:v libx264 -crf 23 -c:a libvorbis b.mp4
>
> Problem:
> Only 1 core used, not all 4 cores like with libx264, but also on 100% if I
> use:
> $ ./ffmpeg -i a.mp4 -c:v libvpx-vp9 -crf 23 -c:a libvorbis b.webm
>
> Problem:
> And trying to use all 4 cores, although all 4 cores are used now, it's only
> on ~60-75% utilization (~250% in top):
> $ ./ffmpeg -i a.mp4 -c:v libvpx-vp9 -crf 23 -cpu-used 4 -threads 4 -c:a
> libvorbis b.webm
> (changing  -cpu-used  and  -threads  higher than 4 values was neither faster
> nor slower).
>
> What do you think? (See already mentioned suggestions in 029274.html thread.
> They unfortunately didn't help.)
> John, the maintainer of the "Linux Static Builds"
> (https://ffmpeg.org/download.html), says it might be due to libvpx-vp9 not
> being optimized yet and maybe someone else has an idea.
> Can anyone try these libvpx-vp9 commands and say how many % in $ top are
> used?
> My OS is Ubuntu 15.04 but I don't think this is the reason. My CPU has no HT
> support, only 4 real cores (84W TDP Haswell).

Do you get the same results using vpxenc and the appropriate flags?

Cheers

Tom