When the user installs a missing gstreamer codec, This TBH might be more work than is worth the effort. It's required to run the plugin scanner in a child of the UI process, for one. Also, any approach that doesn't involve restarting the web process will require changes in gstreamer. For discussion of this issue, see: https://bugs.webkit.org/show_bug.cgi?id=140131 https://bugzilla.gnome.org/show_bug.cgi?id=742617
When the user installs a missing gstreamer codec, it should then be possible to play the media with the codec. Currently this should work fine (sans the current crasher bugs ;), but seccomp filters will break this.