User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0 Build ID: 20150402191859 Steps to reproduce: I have 37.0.2. Version 64bit. I have Debian Jessie 8 64bit. Since 25 april 2015 this is official release. I wanted to play video from Youtube embedded on another page. I also wanted to play videos on Youtube directly. Actual results: Embedded video doesn't played. I also can't play some newer videos directly from Youtube. It is caused because of lack of H.264 support. VP8 works but Youtube doesn't support it any more on embedded videos. It turns out that ffmpeg in Debian Jessie is not present. So there isn't gstreamer0.10-ffmpeg package. Expected results: Firefox should use libav instead of ffmpeg. Iceweasel plays well H.264 videos on the same system.
Hi. I experienced similar problem. On Debian 8 amd64 (codename Jessie) and firefox 37.0.2 i can play youtube videos in 360p only. On Debian 7 amd64 with the same firefox version i can play the same videos in 360p, 480p, 720p. It seems that firefox use gstreamer0.10-ffmpeg (which is no longer avalible in Debian 8) instead of gstreamer1.0-libav package.
It really depends on bug #947287. GStreamer 1.0 is already supported, but by default Firefox is built against GStreamer 0.10 still.
This is now addressed with ffmpeg, so gstreamer is no longer needed for it.
gstreamer is going in bug 1234092