Currently system-ffmpeg use flag is masked for www-client/chromium-94 as it's not possible to build it using system ffmpeg. It's possible to build chromium-94 with system ffmpeg using https://github.com/archlinux/svntogit-packages/blob/packages/chromium/trunk/chromium-94-ffmpeg-roll.patch patch *reverted* eg. eapply -R patch. Patch is borrowed from Arch folks, but I came to similar after investigating the problem. Reproducible: Always
Created attachment 740799 [details, diff] Patch for system-ffmpeg in chromium-94 Patch has to be reverted to allow building chromium-94 with system ffmpeg.
That only works as long as you haven't installed media-video/ffmpeg-9999, because first_dts was moved to internal API: https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/591b88e6787 You can unmask system-ffmpeg and apply the patch locally, but we won't add it to the tree.