YouTube videos playback in Firefox glitches

Since recently, YouTube video playback is seriously glitch-ridden. Anyone setting something like this? Is there some setting which could cause something like this which I could have changed? (Not that I remember changing something, but…)

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I am also seeing this. It has been reported here. It doesn’t occur with other browsers, does it?

I would probably put this topic into the Help or Cafe category.

You can have a look at this site. You will see that webm and Theora videos play fine in Firefox 35 but the H.264 video doesn’t. In the previous versions of Firefox (34 and below) the H.264 videos didn’t work at all on the Fairphone. Back then YouTube recognized that H.264 doesn’t work and provided webm instead. That’s why it worked before.

From the perspective of free software, the H.264 standard is problematic because it requires patent licensing. Webm and Theora on the other hand are completely open formats. Unfortunately most videos on the web are now using the H.264 standard.


Thank you for the interesting details!

I have a question now: Is there a way to disable H.264 and make YouTube provide webm again?

Edit: I downgraded to Firefox Mobile 32 now, and YouTube works again. This issue also doesn’t appear anymore: Scrolling problems. Maybe a higher version also works though.

If you search for mp4 in the about:config page you find several options. I set media.fragmented-mp4.enabled to false. Then YouTube videos work again without flickering.


In the Firefox beta it works well too!
So with the next update it should work again!

Doesn’t work for me, this video e.g. doesn’t start (turning circle).

Worked for me. Don’t see what @Stefan describes. Hm. Something else wrong there?

Should be fixed in Version 37 (current nightly if someone wants to test it)
(update: fixed in 37, uplift requested for 36)


Yeah, it does work of course! I had changed the wrong parameter, but now I modified the one mentioned by @fair2fair. :slight_smile:

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