Here's an useful website if you want to make the code more readable: http://jsbeautifier.org/

Chrome also has a button[0] to do this automatically in the Developer Tools, which is what I used when I wrote the initial comment.

[0]: https://developers.google.com/chrome-developer-tools/docs/ja...

I'm using Archlinux and I have the H.264 GStreamer plugin installed (as well as base+bad+good+ugly codecs), but with Firefox 26 I still can't play a lot of YouTube videos when Flash is disabled, for example when I try to play Gangnam Style it tells me "The Adobe Flash Player is required for video playback".

Is that related to advertisements? Would it be possible to develop a plugin or a GreaseMonkey script that would allow to play every YouTube video in HTML5 with Firefox? If yes, does it exist?