We're running a patched version of ffmpeg which enables multi-threaded VP9 support. This needs to be rebased to ffmpge 3.2.15.
For the record, the steps to validate that VP9 multi-threading support works as expected in the new ffmpeg build:
- Download https://upload.wikimedia.org/wikipedia/commons/6/69/Wall_of_Death_-_Pitts_Todeswand_2017_-_Jagath_Perera.webm (which is a VP8 file)
- Transcode it to VP9 using
ffmpeg -i Wall_of_Death_-_Pitts_Todeswand_2017_-_Jagath_Perera.webm -c:v libvpx-vp9 -threads 8 -row-mt 1 -b:v 5M reencode-vp9.webm
(without the backported patch, the command would fail as row-mt isn't present in 3.2 by default)
Mentioned in SAL (#wikimedia-operations) [2020-07-31T11:16:36Z] <moritzm> imported ffmpeg 3.2.15-0+deb9u1+wmf1 to component/vp9 for stretch-wikimedia T259336