Noticed from T226713: Run cleanupTranscodes.php for current midi files... There's no way to filter by a file specific type to just enqueue those types in requeueTranscodes.php...
We have a useful index... So as long as we pass in img_major_mime too in some way, we're already setting img_media_type to AUDIO or VIDEO
CREATE INDEX /*i*/img_media_mime ON /*_*/image (img_media_type,img_major_mime,img_minor_mime);
Probably better than a LIKE on img_name?