Doing some other poking I'm noticing failed video transcode reports on audio files... I think I regressed something in one of my patches last month or so with the transcodes, where it's trying to run things it shouldn't. The audio transcodes of videos work - producing what I saw initially - whereas the video transcodes of audio files fail out.

CC'ing Aaron since he was seeking some bad failure stats in the transcode queue and may want to track this as well.

This is now covered by fix in review: https://gerrit.wikimedia.org/r/#/c/219586/