No Extension for Firefox Since you are Linux you should be looking on the flavor of install in your forum for that information.

Please let us know if this solved your issue or if need further assistance.

Thanks, but after all the grief I just went through trying to get the sound back on my local files, I am not going to reinstall it on my system. If there is no extension for Firefox, I guess I will be using a different browser for videos.

Ok, not heard that one before. Everyone else installs as to how Linux suggests.

You do not need a plugin for PulseAudio. PA only needs to be installed at the OS level.

See also:

• https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues

All I know is that I started having problems with my sound after I installed PulseAudio, and they went away after I removed it. I have a very old sound card, which could have something to do with the issue, but it works for everything except videos on Firefox, so I will leave it that way for now. From what I am seeing, Windows has not supported my card for over fifteen years, so I guess I am lucky it still works. I was just hoping there was a way to fix the sound in Firefox without touching anything else, but apparently not. Thanks.

Sounds come from the Sound driver or Software driver you installed FF only uses the drivers from there to play the sound. Failed audio for most part is corrupted drivers or bad install or uninstall and the Browser only uses what is provide for sound drivers by the Sound drivers. And if you installed any other codecs that could also cause the problem if they aren't configured correctly.

Thanks to everyone for trying to help, but I think this question needs to be marked as solved, or more accurately, unsolvable. I still don't understand why the sound is fine for all of my local files, and it is fine for videos watched through other browsers, such as Chrome and Brave, but Firefox wants to require me to install PulseAudio. Since the same videos work everywhere except in Firefox, the problem cannot be caused by the videos themselves or my system sound drivers. It looks like I will just have to use a different browser, since Firefox apparently doesn't have an acceptable solution for me.

Alsa support was dropped starting Firefox 52.0 and later. Some Linux distros may have delayed this change with their own Firefox packages.

You could compile Firefox yourself with --disable-pulseaudio --enable-alsa

Keep in mind that if you do this you will not get updates from Mozilla as it will be a third-party build.

Bug 1247056 - Require PulseAudio to play sound on Linux

Thanks. This at least lets me know what happened. It would have been nice if they had given some advance warning. Bye bye Firefox! It was nice while it lasted, but as they say, there are other fish in the sea.

If they had delayed the change till Firefox 53.0 then the 52.0 ESR could have been a option for a while as the last update 52.9.0esr will be out July 3rd.