The job runners which are working as video scalers (in the past this was a dedicated role) are using a repository component (ffmpeg-vp9) which installs a custom ffmpeg and lbvpx build which supports the VP9 codec.
After the reimage of the mw* servers the component is added to apt sources, but only the stock ffmpeg version got installed (i.e. the upgrade to the VP9-enabled build didn't happen).
We need to
- upgrade the reimaged hosts with cumin
- fix puppet to properly install it after a reimage (can be tested with the codfw ones which are not yet reimaged)
- find out whether any encodes failed and need a re-spin