Youtube hangs Firefox with HDMI audio enabled

[hackel]

If I have my output device set to "HDMI / DisplayPort - Built-in Audio", playing a Youtube video on Firefox causes it to hang. It initially loads fine, but nothing happens. The UI is still responsive at this point, and I can scroll the page, switch tabs, etc. However, if I then try to open a new tab or navigate to a new page, Firefox hangs completely and I have to kill it.

If I switch the audio device back to internal speakers, everything works fine.

This only started happening some time in the last week. Previously, I observed a different behaviour, where Youtube videos simply wouldn't play audio on HDMI unless I already had an audio stream initiated from another app. It never hung the browser, though.

I first observed this on Firefox 76 beta, then 77, and now I have confirmed it on the Ubuntu package of Firefox 75, all with a new, clean profile.

Also, I *can* play audio on other sites like Pandora over HDMI. This seems to be YouTube specific somehow.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: firefox 75.0+build3-0ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Uname: Linux 5.4.0-29-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: hackel 5714 F.... pulseaudio
BuildID: 20200403170909
CasperMD5CheckResult: skip
Channel: Unavailable
CurrentDesktop: GNOME
Date: Tue May 5 12:42:54 2020
DefaultProfileExtensions: extensions.sqlite corrupt or missing
DefaultProfileIncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
DefaultProfileLocales: extensions.sqlite corrupt or missing
DefaultProfilePrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:733
DefaultProfilePrefSources: prefs.js
DefaultProfileThemes: extensions.sqlite corrupt or missing
ExecutablePath: /usr/lib/firefox/firefox
ForcedLayersAccel: False
InstallationDate: Installed on 2019-12-03 (154 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
MostRecentCrashID: bp-576d985d-7cf9-49c6-85be-6b8db0200424
Profile0Extensions: extensions.sqlite corrupt or missing
Profile0IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
Profile0Locales: extensions.sqlite corrupt or missing
Profile0PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:733
Profile0PrefSources: prefs.js
Profile0Themes: extensions.sqlite corrupt or missing
Profile2Extensions: extensions.sqlite corrupt or missing
Profile2IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
Profile2Locales: extensions.sqlite corrupt or missing
Profile2PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:733
Profile2PrefSources: prefs.js
Profile2Themes: extensions.sqlite corrupt or missing
Profiles:
 Profile1 (Default) - LastVersion=77.0/20200504222419 (Out of date)
 Profile0 (Default) - LastVersion=75.0/20200403170909
 Profile2 - LastVersion=72.0/20191203141951 (Out of date)
RunningIncompatibleAddons: False
SourcePackage: firefox
SubmittedCrashIDs:
 bp-576d985d-7cf9-49c6-85be-6b8db0200424
 bp-c666b594-be1c-4e99-aa85-9e7ef0200424
UpgradeStatus: Upgraded to focal on 2020-04-24 (10 days ago)
dmi.bios.date: 02/06/2020
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.6.0
dmi.board.name: 018W12
dmi.board.vendor: Dell Inc.
dmi.board.version: A02
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.6.0:bd02/06/2020:svnDellInc.:pnXPS157590:pvr:rvnDellInc.:rn018W12:rvrA02:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 15 7590
dmi.product.sku: 0905
dmi.sys.vendor: Dell Inc.

[Olivier Tilloy (osomon)]

Thanks for the report. Could you please test mozilla's official firefox build (from https://www.mozilla.org/firefox/download/) and report whether it's similarly affected?

[Launchpad Janitor (janitor)]

[Expired for firefox (Ubuntu) because there has been no activity for 60 days.]