I forgot to mention, I'm running firefox on fedora 39

Install ffmpeg from the RPM Fusion repo:

sudo dnf install ffmpeg

If you are using the flatpak version, you need to install ffmpeg with matching runtime version as Firefox (mine is currently 23.08):

flatpak info org.mozilla.firefox
flatpak install org.freedesktop.Platform.ffmpeg-full

thanks for replying. unfortunately, this issue isn't solved with this. ffmpeg repo was already installed and i tried replacing the existing package in case there was some breakage but that didn't really affect the problem at all.

Do you have the same issue with Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf

Try downloading Firefox from Mozilla. Download, unzip, and run firefox-bin from the folder and see if you have the same issue. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

Can we get system info. I like to use neofetch. see screenshot

Operating System: openSUSE Leap 15.6 KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.110.0 Qt Version: 5.15.8 Kernel Version: 6.4.0-150600.4-default (64-bit) Graphics Platform: X11 Processors: 16 × AMD Ryzen 7 PRO 6850HS with Radeon Graphics Memory: 62.1 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: HP Product Name: HP EliteBook 865 16 inch G9 Notebook PC

Does it still happen with the flatpak version? Don't forget to install the ffmpeg-full flatpak package as mentioned previously.