In video.js mode, the scrub bar on video/audio player displays backwards, counting playtime from the right instead of from the left.
(Media controls should look the same in RTL as they do in LTR, which is to say "forward" is to the right. See T44471 for past problems with MwEmbedPlayer.)
This is probably an upstream video.js issue. seems to be a CSSJanus issue; upstream CSS works in isolation.