MP4a is an audio codec. According to YouTube, the video that you linked to above is using the AVC1 codec, also known as H.264 or just MP4, or at least that is what YouTube has decided to send to my Bionic system running Firefox 86.0.1. Firefox has built-in support for H.264 video.
Can you confirm that YouTube is sending you AVC1 video? What Firefox extensions do you have installed. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1916301 Title: I can't play live videos on YouTube (problem with live transmission) - Ubuntu 18.04.5 Status in firefox package in Ubuntu: Confirmed Bug description: Dear Launchpad Team, I can't play live videos from Youtube. I have problem only with live transmission. Normal videos works fine. I noticed that I also have this same problem on Focal (now I checked this on Bionic - Ubuntu 18.04.5). On Lubuntu 18.04.5 on other machine I don't have this problem. I can play on Lubuntu all Youtube videos. What is a problem? Do you know? I think that by default Ubuntu have not necessary package to play live videos on Youtube. Have I right or this is a bug? On Answers section on launchpad anyone can't tell me if it is a bug so this is why I report this bug now. If it is not a bug I am very sorry and you can delete this report now. Example I have problem with this video: https://www.youtube.com/watch?v=21X5lGlDOfg I used debugger by youtube and this is output of this: "debug_error": { "errorCode": "html5.unsupportedlive", "errorMessage": "Ten format wideo nie jest obsługiwany.", "Nx": "HTML5_NO_AVAILABLE_FORMATS_FALLBACK", "cj": ""," If it is a bug can you fix it? UPDATE: Today I updated my firefox to the newest version 86.0. This bug still exists. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1916301/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
