Hi D, On Tue, Nov 24, 2015 at 14:31:58 +0100, D wrote: > I played setting the values higher but it was neither faster nor slower. > Average 4 cores utilization is still ~80%.
BTW, how do you define "utilization"? I believe in "top", 100% equals one core's usage, so you should be able to achieve 400%. Below, you use the term "100% on all 4 cores". That said: I don't know much about libvpx, but this page: http://wiki.webmproject.org/ffmpeg/vp9-encoding-guide and more explicitly this one: https://github.com/Kagami/webm.py/wiki/Notes-on-encoding-settings says to use "-tile-columns" along with "-threads". -tile-columns slightly affects output quality but it's the only mechanism in VP9 to provide multithread encoding and decoding. According to that, "-tile-columns" apparently defaults to 6. OTOH "ffmpeg -h" says "-1", which corresponds to not explicitly setting it to the encoder. And according to the encoder's sources: > By default, the value is 0, i.e. one single column tile for entire > image. So 6 (correspnding to 2^6 columns) is likely not the default, but 0 (corresponding to 1 column), which is not beneficial to threading. Disclaimer, again: I know nothing much about libvpx or VP9. ;-) Moritz _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
