You are not logged in.
Hello,
Since upgrading to firefox 42, whenever I fullscreen a video (e.g. Youtube or Vimeo) my screen fills with a black canvas (as if it's about to go fullscreen), and then the canvas disappears leaving only the browser. After this the browser is kind of borked and I need to restart it.
I can install flashplugin to have working fullscreen again, but I'd rather not do that.
I'm also using xmonad, so I'm wondering if it's a problem with how applications request fullscreen access, but this has never been a problem before firefox 42. I'd appreciate any tips on how firefox 42 may have changed how html5 handles video.
Thanks!
Last edited by alex404 (2015-12-14 18:47:15)
Offline
Go to the about:config page of firefox. Click the I promise button. Type in media.media. You get some boolean values. Double click on all the ones that say false to turn them true. Now type in media.frag. Change all the values to true except the last one that says "Use blank decoder". Now go to http://www.youtube.com/html5. All the formats should be shown as working. Choose the use html5 player if you haven't done it already. Hope this helps.
Last edited by Ambyjkl (2015-12-12 10:30:23)
Offline
Hey, thanks for the tips, but I've already been through that excercise. All the extensions listed on the youtube/html5 site are checked, and I'm using the html5 player.
This seems to be related to the full-screen-api stuff in about:config, but none of the options there seem relevant.
Offline
No such problems in Compiz. However, one change I do notice is that the YouTube html5 player now has a fade to black transition when entering and exiting fullscreen video whereas before the switch was immediate. I would imagine that's the root of the problem however I don't know how you would disable the fading transition.
Offline
Well, I get the fading transitions to, but only when I have compton on. Killing that means no transitions, but the player is still broken. Still, there must have been some change to how firefox handles html5 video if it is now launching a distinct window.
Offline
Looking at the Firefox 42 release notes, it lists the following: "Media Source Extension for HTML5 video available for all sites"
Perhaps that's what has changed. Have you checked to see whether you have the same issue in Chromium?
Last edited by Chazza (2015-12-13 22:07:27)
Offline
Chromium works fine, and according to youtube.com/html5, is working with all the extensions (like firefox 42).
Interestingly, the difference is that when Chromium goes fullscreen it only fills the browser window, whereas Firefox tries to fill my entire screen. Typically no applications that I run (not even games) can go full screen outside of their tile in xmonad, so firefox is definitely doing something new and weird that I can't wrap my head around.
Offline
I tested this in Motif Window Manager (as provided by openmotif) and had similar results. In Chromium, all is well - a video maximises to fill the window (but not further) just like your experience in xmonad. In Firefox, there's no visible change (no flash to black) but the browser becomes so unresponsive that it's like it has locked up. When the browser is restarted, it's in its F11 fullscreen mode. So I think what's happening is that when you maximise a html5 video, Firefox is just putting itself into fullscreen mode and MWM at least doesn't like Firefox's fullscreen mode. Perhaps that is what's happening to you as well. Does the browser semi-lock up (or similar) when you put it in fullscreen mode under xmonad?
Offline
it does indeed, pretty much exactly as you describe. Also, if I hit the general fullscreen button in firefox (F11) it also semi-breaks the browser in the same way.
Last edited by alex404 (2015-12-14 11:04:49)
Offline
Just tried with FVWM. Fullscreen mode and fullscreen videos work properly there, no compositor running either. So this must be wm specific. I'll try and examine the xprop output of Firefox in a bit. It might be that fullscreen mode sets wm hints that Xmonad and MWM don't like.
Offline
The xprop output doesn't seem to be any different. Still, I did a little research and I'm wondering if the problem might be to do with EWMH. I'm pretty sure MWM doesn't support EWMH considering that EWMH is supposed to replace Motif hints and according to this, Xmonad doesn't seem to support it by default either. However, FVWM and Compiz do support it and they work fine. Perhaps if you enable EWMH in Xmonad (if you haven't done so already) as per the Wiki then Fullscreen in Firefox will start working.
Offline
So you indeed pinpointed the issue. I had infact enabled EWMH support in xmonad, but I remember now that when I wrote my config file ages ago, I avoided the fullscreen ewmh hook, because it meant that applications could indeed decide to fill my entire screen. By turning that on, firefox fullscreen support works fine.
Unfortunately, I much prefer being able to keep them in tiles if I desire, and then dropping away my status bar and window decorations when I really want to make things full screen. This has never been a problem for any application until firefox now, which is a rather serious pain in the neck.
Do you have any thoughts on what firefox might be doing differently?
Offline
Okay, there's actually a bug report on this exact issue on firefox:
https://bugzilla.mozilla.org/show_bug.cgi?id=1189622
I'll see if I can't hack a solution to my satisfication, and mark this issue as solved one way or the other. Thanks for all your help.
Offline