i try to make a Javascript where I need to test the ability of playing "video/mp4".
I do that with:
var video = document.createElement('video');
video.canPlayType('video/mp4');
But my Firefox (Version 25.0 / Ubuntu 13.10) returns empty string.
According the Bug I opend on bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=934947
(second comment)
I need to enable gstreamer.
But I dont't know how to do that.