Graphical glitches in YouTube HTML5 player
When I've been playing YouTube videos lately, I've noticed that a bunch of black boxes have been appearing over the player interface (The controls below the video) while the video is playing. Unfortunately, I can't provide a good screenshot, as the boxes come and go too quickly for me to get them. This issue still occurs if I restart Firefox in safe mode. I think it started happening with Firefox 37.
Chosen solution
This problem doesn't seem to occur anymore with the new YouTube player.
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Hello,
Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).
If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:
- Click the menu button
, click Help 
and select Restart with Add-ons Disabled.
If Firefox is not running, you can start Firefox in Safe Mode as follows:
- On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
- On Mac: Hold the option key while starting Firefox.
- On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
(you may need to specify the Firefox installation path e.g. /usr/lib/firefox)
When the Firefox Safe Mode window appears, select "Start in Safe Mode".
If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.
To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.
When you figure out what's causing your issues, please let us know. It might help others with the same problem.
guigs2 said
Hello, Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes). If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:If Firefox is not running, you can start Firefox in Safe Mode as follows:
- Click the menu button
When the Firefox Safe Mode window appears, select "Start in Safe Mode".
- On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
- On Mac: Hold the option key while starting Firefox.
- On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
(you may need to specify the Firefox installation path e.g. /usr/lib/firefox)If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause. To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again. When you figure out what's causing your issues, please let us know. It might help others with the same problem.
As stated above, the issue persists in safe mode.
Sorry I should have been more careful. So this means that it is not due to hardware acceleration or and add on, but it might still be caused by an extension.
- Upgrade your graphics drivers to use hardware acceleration and WebGL
- Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
I did find some other solutions in the ubuntu forums, however I am not entirely sure which version you have.
I think I've seen such moving black glitches as well on YouTube in Firefox 37 on Linux. They are most discernible on the red progression bar. I can't reproduce it, so I don't know what causes it. It is possible that sometimes the player content extends beyond the playing area into the controls area when there are switches between various sizes (i.e a video is available at higher resolution).
cor-el said
I think I've seen such moving black glitches as well on YouTube in Firefox 37 on Linux. They are most discernible on the red progression bar. I can't reproduce it, so I don't know what causes it. It is possible that sometimes the player content extends beyond the playing area into the controls area when there are switches between various sizes (i.e a video is available at higher resolution).
Yes, this is exactly what I'm seeing. This happens most of the time when I watch YouTube videos.
guigs2 said
Sorry I should have been more careful. So this means that it is not due to hardware acceleration or and add on, but it might still be caused by an extension. I did find some other solutions in the ubuntu forums, however I am not entirely sure which version you have.
The problem I have is not video tearing. It is the same thing that cor-el describes.
I am using the latest GPU drivers provided by the Ubuntu repositories. However, according to the troubleshooting information in Firefox, hardware acceleration actually isn't being used, despite being enabled.
I managed to capture a video of the issue happening. I also attached a few representative screenshots from that video in case you can't watch the video.
https://docs.google.com/uc?id=0BzKVhsbqDk0MNGNJd18zcU9fYVk&export=download
Are there any more troubleshooting steps I can try? None of the provided ones have helped.
I am still having this issue, can anyone help?
Its possible to disable hardware acceleration in Flash or in Firefox however these may have been tried already and are only temporary solutions.
guigs2 said
Its possible to disable hardware acceleration in Flash or in Firefox however these may have been tried already and are only temporary solutions.
I've already tried both of those. Neither helps.
Any advice for this? It still happens on Firefox 39.
On Linux hardware acceleration is usually not available, both for Firefox and for Flash.
I assume that the HTML5 media player is used in cases where this is happening?
You can try to disable GStreamer support to see if that makes websites switch to a Flash based player that might work better. about:config: media.gstreamer.enabled = false
cor-el said
On Linux hardware acceleration is usually not available, both for Firefox and for Flash. I assume that the HTML5 media player is used in cases where this is happening? You can try to disable GStreamer support to see if that makes websites switch to a Flash based player that might work better. about:config: media.gstreamer.enabled = false
While I haven't observed the issue with the Flash based player, using that for any extended length of time is highly undesirable. The Flash based YouTube player doesn't support all of the features, Flash will sometimes randomly crash on my computer, since I'm running the Windows version of Flash via Pipelight.
Should I try force-enabling hardware acceleration to see if that fixes the issues with the HTML5 player?
Chosen Solution
This problem doesn't seem to occur anymore with the new YouTube player.