[FFmpeg-user] rav1e encoding only using one core

[Robert Krüger]

Hi,

I'm playing around with rav1e and noticed in my first test that only one
core is used of the 8 (16 virtual) I have. I tried with and without
-threads setting. Since most other codecs behave this way I was expecting
it to use as many cores as possible if not constrained by the command line.

I tried:

ffmpeg -i prores_hq_1080_24p_varying_motives_80s.mov -c:v librav1e -speed 4
-an prores_hq_1080_24p_varying_motives_80s_rav1e_speed4.mp4

and the same with "-threads 8" after the input file with identical results.
Without multithreading this is extremely slow.

Other codec like x264, x265, kvazaar multithread fine with the same built.
So it's not a general problem with multithreading.

Working on OS X Catalina.

Thanks for any hints,

Robert