Anyone actually know why Firefox won't play some YouTube videos?

Random videos on YouTube won't play in Firefox.

These youtube users are making some choice when uploading
their videos. Videos on a channel up until last week
all play fine. The user uploads a new video and it doesn't
play.

I installed Alien Bob's 27.0 flash player - no help.

It just seems odd that this problem continues and I don't think anyone really knows what's going on with this.

Chrome works. VLC works. Firefox doesn't.

"You're browser currently doesn't recognise ANY of the video formats available."

Yet according to Youtube, I have 4 out of 6 decoders available.

I have various versions of Firefox on different computers - when a video doesn't play, it won't play on any of them.

I would like to know what the YouTube user is picking that is preventing Firefox from working so maybe I can tell him not to do whatever it is he is doing.

It's not just YouTube. I have gotten the same error message on several news sites for some of their videos. It appears to affect any Mozilla-based browser. I've tried 4 with same results. Flash's beginnings trace back to 1995 when the Internet was still a fairly small part of most peoples' lives. It's demise is long overdue. 2020 can't come fast enough to suit me.

sometimes if its a Vivo video it will not play if you block the ads or javascripts ie: if you use NoScript or uBlock etc....

Try using the addon UnPlug, it allows you to either download the video, copy paste in a media player or open in a separate tag without unblocking the tracking stuff....You can watch in webm mp4 etc...
https://addons.mozilla.org/en-US/fir...unplug/?src=ss

iirc, installing x264 from SBo solves this problem.

1 members found this post helpful.

55020 - Actually it only solves a select few

That would be really odd, because x264 is supposed to only be an encoder, not a decoder.

Does it need ffmpeg or one of the gst packages? I vaguely remember Firefox used to require that before it would play a lot of videos.

3 members found this post helpful.

I have FF, Nightly, Chrome and it's unstable so anything plays here...

Add: whoops, missed we're in the Slackware forum (from "View Latest Posts") tho may work there?

It's rather impossible to help without linking to at least one of these videos. Are we supposed to go searching for them ourselves?

This may depend on which version of slackware, and therefore which version of firefox, you are using. What does https://www.youtube.com/html5 show? On slackware64-current, all six items are ticked as supported. This should show you at least what is missing in your installation.

1 members found this post helpful.

Try going into your Firefox Preferences menu and in the Content section there's a 'Play DRM content' checkbox.
https://support.mozilla.org/en-US/kb...urce=inproduct

1 members found this post helpful.

Sorry. Here is an example:

https://www.youtube.com/watch?v=dJtbmjfB-OM



Yes, I did have that unchecked but checking it didn't help.


Doesn't seem to. I have slackware64 14.1 and 14.2 running FF 50, 52 and 55. All behave the same.



HTMLVideoElement=yes
H.264=no
WebM VP8=yes

Media Source Extensions=yes
MSE & H.264=no
MSE & WebM VP9=yes

The HTML5 player is currently used when possible.=yes

So I did a little experiment.

I'm on 14.2 with
mozilla-firefox-52.3.0esr-x86_64-1_slack14.2
x264-20170225 from SBo
ffmpeg-3.2.4 from SBo, built with x264 and everything else

At https://www.youtube.com/html5 I get
HTMLVideoElement=yes
H.264=yes
WebM VP8=yes
Media Source Extensions=yes
MSE & H.264=yes
MSE & WebM VP9=yes

And https://www.youtube.com/watch?v=dJtbmjfB-OM plays ok. (Oh. my. god. what squalor!)


So I removed ffmpeg and x264, then restarted firefox.

At https://www.youtube.com/html5 I now get
HTMLVideoElement=yes
H.264=no
WebM VP8=yes
Media Source Extensions=yes
MSE & H.264=no
MSE & WebM VP9=yes

And https://www.youtube.com/watch?v=dJtbmjfB-OM won't play.


So I reinstalled ffmpeg and x264, then restarted firefox.

At https://www.youtube.com/html5 I now get
HTMLVideoElement=yes
H.264=yes
WebM VP8=yes
Media Source Extensions=yes
MSE & H.264=yes
MSE & WebM VP9=yes

And https://www.youtube.com/watch?v=dJtbmjfB-OM plays once again.

Oh ye of little faith
(Edit: Well, actually bassmadrigal did mention ffmpeg...)

I shudder to think what that youtube is going to do to my recommendations

3 members found this post helpful.

Do you like to overspend on "camping" or just won't?

Chrome installed from their website (never logged into google) is my default, FF if something won't fly... worked in both.

FF ESR 52.3.0 (64-bit)
GC 61.0.3163.100 (Official Build) (64-bit)

I still don't think x264 is required as ffmpeg should be able to DEcode h264 without anything extra, it just can't ENcode without x264. But if you compiled ffmpeg with x264, then ffmpeg might bomb silently without it if you try to use it on Firefox without x264. I'd try it out, but it's late and my 14.2 computer is really slow and I don't know how long it would take to compile ffmpeg.

Just go to your youtube history and remove it. I have to do that occasionally when I click on some youtube links in reddit.

2 members found this post helpful.

Well I didn't have ffmpeg installed but did recently add h264 because of this thread. I just installed AlienBob's ffmpeg slackbuild and after hassling with how exactly to enable a few options it compiled in 9 minutes and now all 6 html5 items are checked and so far all previously unplayable FF items play just fine. Damn! I love this community!

1 members found this post helpful.