I can't play live videos on YouTube (problem with live transmission) - Ubuntu 18.04.5

What browsers have you tried please?

Firefox 85.0.1 (64-bit) on Ubuntu 18.04.5 and Ubuntu 20.04.

Like I said on Lubuntu 18.04.5 on other machine I don't have this problem. I talked with person from Lubuntu project and I understand that Lubuntu and Ubuntu is the same so this is strange problem with Ubuntu. I checked on my machine with Lubuntu system and I have installed by default this package:

libwvstreams4.6-extras/bionic,now 4.6.1-11 amd64
libwvstreams4.6-base/bionic,now 4.6.1-11
ffmpegthumbnailer/bionic,now 2.1.1-0.1build1 amd64
libffmpegthumbnailer4v5/bionic,now 2.1.1-0.1build1 amd64

So my question is. I don't have above packages on Ubuntu because this are community packages. So this fix the problem with YouTube if I will install this?

Ubuntu have problems with YouTube live streams by default?

This is link to video with I have problem on Ubuntu: https://www.youtube.com/watch?v=21X5lGlDOfg

Why don't you just try installing these packages to check whether it helps?
If they do not help and if you then do not want to have them on your system any more, then you can easily uninstall them again.

We cannot check whether adding these packages helps on your system. Only you can check your system, we can't.

I don't want install these packages because support of these packages in April will be ended. I asked in Launchpad because I thinked that someone had this same problem and can tell me if it is bug or this is problem with packages.

The packages in question are also available in focal, they will be supported.
On Firefox, check the settings. Top right of browser page click on the gear icon -> Click Privacy & Security Tab -> scroll down to Permissions -> On Autoplay open settings -> Open drop down box for Default for all web sites -> Change setting to: Allow Audio and Video -> Bottom right Save Changes. Then try watching the Live streaming video.

I have other question. Maybe someone have Ubuntu with default packages or live usb with ISO and can tell me if you can play this youtube video (NASA official channel, don't worry): https://www.youtube.com/watch?v=21X5lGlDOfg

I will be try to change some settings in firefox and I hope that this help.

@Bernard Stafford, your solution doesn't work for me. I did all your steps.

On Firefox click Gear Icon -> Click the General Tab -> Scroll down to Digital Rights Management (DRM) -> Check mark the box Play DRM-Controlled Content. Try your video. I hope that helps.

@Bernard Stafford, thanks for your help but this is not work for me. Do you have Ubuntu system with default configuration? If yes, can you tell me if youtube live video work in your system?

I have Ubuntu 20.04, it will not play Live streaming video on youtube. Firefox 85.0.1. I did check that is the current Firefox for Ubuntu. sudo apt-get install firefox

This I did figure out. Open the Ubuntu software center in the search box type: Firefox Their are 2 Firefox's The one installed by default which is 85.0.1 and if you scroll down further their is another. Firefox 85.0.2. I removed the default Firefox and installed the other from the snap store (Ubuntu software center) Oh it will play live streaming video. Thank you for posting this question.

Ok, but why I should download new version. This other firefox is official from Mozilla in main repository? If I will install it this install also some other packages or only firefox packages? I have Firefox 85.0.1 on Lubuntu and on this system I can play live video so I think that this is not problem with firefox version itself. Lubuntu is from Ubuntu family system so it is the same so problem is strange and I want to know what is the problem.

I wanted to link my bug report to your bug report but I can't find this option. I should use option "Mark as duplicate" to my report?

The 2 bug reports are now linked. The other Firefox is the newest version of Firefox 85.0.2 that would be your choice. If you change versions sync your bookmarks or write them down. You will have to start over on bookmarks.

Did you checked what packages you installed when you downloaded this version of Firefox 85.0.2? I think that you installed some additional packages so that is why this works for you. I checked and for example on machine with Lubuntu system I didn't have problem with live transmission video from YouTube but by default in this system I have some packages installed for example libavcodec57.

A "snap" package does not need any additional packages. This is a characteristic feature of snap packages, that they are self-contained and do not depend on anything else (except on the snap software of course)

Meanwhile there is firefox version 86.0-3 available from the snap store (published today).
I suggest that you try this. It is also official from Mozilla and has been packaged by canonical.

sudo snap install firefox

If you install the snap version, then you should uninstall the *.deb version, e.g. with the command
sudo apt purge --autoremove firefox

And if you want libavcodec57 on your Ubuntu system, then install it!
Eventually you should also install the package ubuntu-restricted-extras

Snap version is better? I updated my firefox to 86.0 but by apt install firefox command. I have Canonical version of firefox. Bug still exists but I don't know why Mr. Bernard Stafford didn't have this problem after updating firefox from Ubuntu Software Center. On Bugzilla from Mozilla they told me that libavcodecs57 are probably necessary but If I want to install this my apt want to install more packages -23 packages! This looks strange. I must check if these packages are on my another machine with other Linux system where I don't have problems with live stream YouTube videos.

When I typed apt install libavcodec57 apt want to install these packages:

i965-va-driver libavcodec57 libavutil55 libcrystalhd3 libgsm1 libopenjp2-7
  libshine3 libsnappy1v5 libsoxr0 libswresample2 libva-drm2 libva-x11-2 libva2
  libvdpau1 libx264-152 libx265-146 libxvidcore4 libzvbi-common libzvbi0
  mesa-va-drivers mesa-vdpau-drivers va-driver-all vdpau-driver-all

Why he want to download mesa drivers or i965-va-driver?

"Snap version is better?" It is not necessarily better, but it is different.
If you have a problem with the *.deb version, then you should try the snap version, just for the purpose of testing whether this shows the same problem.

And yes, the 86.0 *.deb package was published yesterday

Both the *.deb version and the snap version are packages by canonical. I do not see any difference in responsibility and licensing.

And yes, there is a dependency chain from libavcodec57 via libavutil55 to libva-drm2 and in turn to libva2 etc.
see e.g. https://packages.ubuntu.com/bionic/libavcodec57

I know that is old topic but on this website (https://packages.ubuntu.com/bionic/libavcodec57) I can't see on dependency these packages:

i965-va-driver libsoxr0 libva-x11-2 libvdpau libzvbi-common mesa-va-drivers mesa-vdpau-drivers va-driver-all vdpau-driver-all

I founded that libva2 suggest to install va-driver-all but this package is not needed. For example in my other computer in Lubuntu these packages are not installed at all so what is the reason that my Ubuntu wanted to install this?

There are three different types of dependencies: "depends", "recommends" and "suggests". only "depends" is a must, the other ones can be deselected.

And there is a dependency chain with one package depending on another one which in torn depends on a third one and so on. packages.ubuntu.com shows only one level, and you have to dig further to see the next level.

What output do you receive for the command

apt --simulate install --no-install-recommends libavcodec57

Thank you Manfred Hampl for apt --simulate install command. This is very helpful and this solve my question. Thank you a lot!