Unfortunately, your browser does not support video playback.

[Irihapeti]

Just tried current image, correct, no video on that and likely other sites.
Easy fix..

sudo apt install gstreamer1.0-libav

That worked on my Ubuntu VM.

If this applies to the live ISO, should someone report a bug?

[VMC]

It works with my installed partition, but budgie, xubuntu, kubuntu don't have libav:

ubuntu gtstreamer before:

dpkg --get-selections | grep gstreamer
gir1.2-gstreamer-1.0:amd64            install
gstreamer1.0-alsa:amd64                install
gstreamer1.0-clutter-3.0:amd64            install
gstreamer1.0-gl:amd64                install
gstreamer1.0-gtk3:amd64                install
gstreamer1.0-packagekit                install
gstreamer1.0-plugins-base:amd64            install
gstreamer1.0-plugins-base-apps            install
gstreamer1.0-plugins-good:amd64            install
gstreamer1.0-pulseaudio:amd64            install
gstreamer1.0-tools                install
gstreamer1.0-x:amd64                install
libgstreamer-gl1.0-0:amd64            install
libgstreamer-plugins-base1.0-0:amd64        install
libgstreamer-plugins-good1.0-0:amd64        install
libgstreamer1.0-0:amd64                install

After the libav was added and it worked.

[mc4man]

Actually after taking a look it's libavcodecXX that firefox needs for such vids, local or online.
By default it can play webm so it works without libavcodecXX on youtube or on any webm file, vp8/9 or av1, opus audio.

[VMC]

Actually after taking a look it's libavcodecXX that firefox needs for such vids, local or online.
By default it can play webm so it works without libavcodecXX on youtube or on any webm file, vp8/9 or av1, opus audio.

Why does Budgie work without it?

[mc4man]

Why does Budgie work without it?

According to manifest it ships with libavcodec58:amd64 (7:4.2.2-1ubuntu1
You don't have it installed?

[VMC]

According to manifest it ships with libavcodec58:amd64 (7:4.2.2-1ubuntu1
You don't have it installed?

Correction, I do:

$ dpkg --get-selections | grep libavcode
libavcodec58:amd64                install

update:So that means Budgie has that codec, ubuntu doesn't. I need to check x/kubuntu also.

[zika]

Two things migh help (even though old... )
1. try to install libavcode-extra
2. firefox about:config media.libavcodec.allow-obsolete false>true
No promises, no guarantee.

[VMC]

On my Budgie ,media.libavcodec.allow-obsolete = "false", and the web videos work.