you can also try http://media02.nfl.info/NFL/Media/2014/Video15/Officiating_Media_Video_12-05-14.mp4 if that works better -- not sure why it would say file is corrupt, as you saw with chrome it clearly isn't...
here are related packages i have installed when it crashes: libvdpau1:amd64 0.7-2 vdpau-va-driver:amd64 0.7.4-3 libva-drm1:amd64 1.3.1-3 libva-glx1:amd64 1.3.1-3 libva-wayland1:amd64 1.3.1-3 libva-x11-1:amd64 1.3.1-3 libva1:amd64 1.3.1-3 libgstreamer-vaapi1.0-0:amd64 0.5.9-2 gstreamer1.0-vaapi:amd64 0.5.9-2 firefox 34.0+build2-0ubuntu0 nvidia-331-updates 331.89-0ubuntu5 nvidia-331-updates-uvm 331.89-0ubuntu5 nvidia-cg-toolkit 3.1.0013-1 nvidia-libopencl1-331-updates 331.89-0ubuntu5 nvidia-opencl-icd-331-updates 331.89-0ubuntu5 nvidia-settings 331.20-0ubuntu8 removal of gstreamer1.0-vaapi also removes libgstreamer-vaapi1.0-0 and libva-glx1, after which firefox is able to successfully play and seek within the video without crashing. ** Changed in: gstreamer-vaapi (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1395070 Title: gstreamer-vaapi + nvidia driver causes firefox to crash on animated gifs / video tags To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gstreamer-vaapi/+bug/1395070/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs