Certain types of video playback stopped working in Firefox

Recently I started having issues with video playback in Firefox on Tumbleweed. The Instagram video player says “Sorry, we’re having trouble playing this video”. I’m seeing similar symptoms on other sites. Video playback works fine in Chromium.

Here’s my codecs section from about:support:

Anything else I should check?

Install the H265 codec from packman

sudo zypper in libx265-215

or all codecs

sudo zypper in opi && opi codecs

This worked for me, thanks. Any idea why I suddenly need to enable Packman for this? This worked before, and it worked in Chromium without Packman. I’d rather not enable an unsupported repo.

The explanation is in the linked thread.