Videos fail to load in Nightly (50.x and 51.x)

[Internet User]

I have a issue where on some sites with webm/mp4 video's in the <video> tag won't play.

expected behavior
1 ) click on a video
2 ) video plays

what I'm getting is...
1 ) goto https://oddshot.tv/shots or some similar site
2 ) click any clip and it says something along the lines of "The media could not be loaded, either because the server or network failed or because the format is not supported", or on another site a similar message of "Video format or MIME type is not supported"
3 ) video won't load, it just shows that error.

disabling e10s leads to it working fine and playing the video (though I did still see the error a couple times), however disabling e10s makes FF perform like a pig.

I've replicated it with a fresh profile as well as on my main. on that oddshot one, there is the error in the console from the site itself with their player.js stating the aforementioned mime type issue, nothing about noscript blocking anything though, its just as if it kills the <video> tag and refuses to load the mp4, but if I right click the video and hit "view video", it plays the mp4 by itself just fine.

it also happens in FF Aurora (Dev)

any idea?

[therube]

So does this have anything to do with NoScript?
As in did you disable NoScript restart & confirm that the videos then play as expected?

...

Oh, wait, I might run into that all the time, or at least kind of, though in my case its often what I want. I'll get the NoScript placeholder & I'll center-click that to open the link in a new Tab & with that, assuming it plays, it plays using the native player rather then the particular player that the particular website happens to use.

And if that is the case, then its particular settings in NoScript, probably (in Plugins, or whatever it says) 'apply to whitelisted sites too'?

And actually, where I think it comes about most times is when you have allowed the (some "cdn"), but not the site you're on. So in your example I would not have allowed oddshot.tv, but would have allowed where it is that the video itself happened to be housed at.

(Can't check anything, cause I'm on XP now & don't think it will work for me at all?)

[barbaz]

I can confirm the bug in Dev Edition. Disabling NoScript does get it working.

Linux users: need to set about:config > media.libavcodec.allow-obsolete to true in order to be able to test this.

disabling e10s leads to it working fine and playing the video (though I did still see the error a couple times), however disabling e10s makes FF perform like a pig.

Most of the users on this forum don't have e10s enabled. Did you really think that so many people would use a browser that performs like a pig?

Let us know if you'd like help getting that working while waiting for this bug to be fixed.

[barbaz]

Split the dross off to viewtopic.php?f=24&t=22211 .