Firefox cannot play certain Twitter gifs on Windows 7
Examples of broken gifs:
https://twitter.com/wannaODIN_/status/1169143681976283136
https://twitter.com/RedTestament/status/1169139822100930561
https://twitter.com/_t3nshi/status/1169122796573736960
As far as I can tell, this is mainly a Windows 7 problem. I have done a fair bit of testing with gifs I've made myself, and while I don't exactly know how gif "encoding" or whatever works, it seems to be a problem with how Twitter converts certain gif versions.
If I make a gif with Aseprite 1.2.13-x64 the gifs do not work, and show up as black. However you can still download them as a video, reupload them, and then they work, which is kinda weird but I assume twitter re-converts the videos into something else.
However if I make the same gif with Aseprite 1.2.9 which is at least a year older, they work on Twitter.
I've seen some references about H.264 Level 5.2 not working on Windows 7, and maybe that might be the issue? If so, is there any way to get Level 5.2 media to play on Windows 7? https://bugzilla.mozilla.org/show_bug.cgi?id=1479203#c10
Using MediaInfo to check the files of the videos in question they say that they are using AVC (Main@L5.2) (CABAC / 4 Ref Frames), while the "gifs" (yes I know that they are just videos on Twitter) that DO work are AVC (Main@L5).
Krejt Përgjigjet (6)
kashoucanavi said
Firefox cannot play certain Twitter gifs on Windows 7
Please explain the problem in detail. What happens? What are the exact error message(s) ?
The videos are simply black and do not play. If there's any way to get some kind of debug message, I do not know of it.
Make sure you are not blocking content.
Start Firefox in Safe Mode {web link}
A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?
One issue that seems more common lately is Firefox's Content Blocking. When it is blocking content in a page, a shield icon will appear at the left end of the address bar next to the padlock icon. This article has more info on managing this feature:
I can confirm the issue. I think you're right. Actually you don't need any support from us.
So basically "Windows 7 doesn't support Level 5.2 media codecs, you're screwed"? That just makes me sad.
And just for confirmation, yes, it's the same in safe mode.