I'm on Ubuntu 14.10.
FF 35 has support form H264 and VP8, but not MSE and VP9. That is ok, and confirmed by youtube html5 page, https://www.youtube.com/html5, as you see the screen #1 here: http://4.ii.gl/Z8rHCj-Ao.png FF35 is the stable version installed from official ubuntu repo.
FF 37 (dev edition), downloaded, uncompressed and launched (no ppa), has support for MSE and VP9, a new feature in FF, but H264 is gone. See screen #2 here: http://4.ii.gl/VtNFAbVCy.png
Is there a way to have FF37 "see" the H264 driver?
Thanks.