How to improve video quality in Firefox/Ubuntu guest?

[abcuser]

Hi,
on Windows 10 host updated to latest updates I have installed VirtualBox 6.1.32 and also installed Oracle Extension Pack. In BIOS I have checked AMD virtualization is enabled for CPU.
I installed Ubuntu 22.04 Desktop daily build and update it to the latest updates. I installed VirtualBox Addons and rebooted Ubuntu guest.

VirtualBox settings for guest I have set:
- 8 GB RAM
- 8 CPUs (out of 16) - on Windows host Task Manager I see: 1 CPU Socket, 8 Cores and 16 Logical Processors, Virtualization=Enabled.
- Video Memory: 128 GB
- Screen Resolution: 1920:1080 (just like on Windows host)

Started Ubuntu guest and opened Firefox 97 installed from flatpak Flathub repository. Then I pointed to my ISP web page for watching TV. Now the problem appears. Audio works perfectly. But video stays behind and video quality is noticeable lower. Video frames are "jumping" and looks like little bit slow motion. Video is set to 720p.

If the same web page is watched on Firefox 97 on Windows 10 host, then video is perfect.

What can I check to improve video quality on my Ubuntu guest?

Regards

[scottgus1]

Start the VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.

[abcuser]

See attachment.

Exact steps I performed to collect VBox log files.
1. On host I made sure machine was powered off and not in saved state.
2. On host I deleted all of the VirtualBox log files for Ubuntu guest.
3. On host Windows in Task Manager I made sure CPU dropped bellow 1% before proceeding.
4. I started the Ubuntu guest.
5. In guest I started Firefox.
6. In guest I checked "top" command in terminal and waited CPU dropped bellow 1% before proceeding, to make sure guest fully booted.
7. In guest Firefox I typed URL of my ISP provider's TV web page and started to see one fo the TV channels.
8. Problem with slow video appeared. I waited for e.g. ten seconds and then I force powered off Ubuntu guest.
9. On host I zipped files from Ubuntu guest Log directory and attached them to forum.

[AndyCot]

Lookup "flatpak Flathub" and you will find that it effectively runs apps in a sandbox and as such you are stuck with what came in the flatpak. I learnt this the hard way 2 years ago and NEVER have install any flatpak apps since then.

I have seen a number of posts on various sites all having issues with flatpak installs and people who did not use flatpak not having issues.

[abcuser]

Now I did some performance tests.

I installed:
1. Firefox 97 flatpak from Flathub repository.
2. Firefox 97 snap from snap repository.
3. Firefox 97 deb package from http://www.mozilla.org web page.

I did two tests for all three installed Firefoxes with quickly changing videos in Firefox:
1. Open Youtube "Formula 1" racing car video: https://www.youtube.com/watch?v=APd12qg_EBA
2. Open my ISP web page and futsal soccer players from yesterday evening at exact time.


FIREFOX WITH FLATPAK:
Test 1. Youtube video is playing without an issue. Looks like no problem with video.
Test 2. Problem with video, slowly moving frames etc.

FIREFOX WITH SNAP:
Test 1: Youtube video is playing without an issue. To eye it looks very similar to Firefox/flatpak.
Test 2: I see no video problem. Looks like video is working fine. Much better then Firefox/flatpak.

FIREFOX WITH DEB:
Test 1. Youtube video is playing without an issue. Looks similar to Firefox/flatpak and Firefox/snap.
Test 2. I see no video problem. Video looks similar to Firefox/snap but pretty much better then Firefox/flatpak.

CONCLUSION:
I have noticed for all install types of some DRM video plugin was automatically installed on first Firefox launch using ISP web site. It may be some imperfection in this DRM that only has some problems with Firefox/flatpak, but it works fine in Firefox/snap and Firefox/deb. I don't know if this is related to VirtualBox only or the same issue may appear on bare metal Ubuntu install (I don't have spare machine to test this and I don't want to mess with dual boot on this computer).

@AndyCot, in this case it really looks like some performance problem related to Firefox/flatpak with my ISP web site TV show using Firefox DMR video encoder. But I can't confirm this is ot isn't related to Firefox/flatpak running inside VirtualBox.