>>652050WebM related. You should read projects issues more carefully. The issue you link to is closed because they've added it. I should have pointed out that right now you need to download a nightly build to use WebM. (Go to
https://handbrake.fr/nightly.php and click something like "HandBrake-20190406-5b4771f_x86_64-Win_GUI.zip".) That's my bad.