I am Aaron from Mozilla Firefox for Android QA. We noticed that in our browser, we're unable to start any HTML5 H.264 video. It seems like there's an issue tapping the play button on mobile. On desktop, one can tap the play button but then no video is loaded at all.
We used the video from the Quick Look: The Last of Us as an example: http://www.giantbomb.com/videos/quick-look-the-last-of-us/2300-7467/
Looking at the error console we noticed
[10:03:39.007] <source> element has no "src" attribute. Media resource load failed. @ http://www.giantbomb.com/videos/quick-look-the-last-of-us/2300-7467/ [10:03:39.007] All candidate resources failed to load. Media load paused. @ http://www.giantbomb.com/videos/quick-look-the-last-of-us/2300-7467/ [10:04:09.364] TypeError: Value does not implement interface Node. @ http://vidtech.cbsinteractive.com/h5/2_2_0/CBSI_PLAYER.js:304
We tested this on current releases of Firefox for Android on Google Play and have a bug on file at Bugzilla for investigation over at: https://bugzilla.mozilla.org/show_bug.cgi?id=884280
Firefox for Android supports HTML5 H.264 video playback so this seems to be an issue with the player or correctly fetching a source for the video element.
If you guys can take a look at this it would be greatly appreciated for as it affects users who frequent your site using Firefox for Android.
Aaron (Sr Mozilla QA Engineer)