Last I checked, the limit was 24MB, no idea about marathon maps, and it wouldn't even let me start the upload if my video was larger than that.
The upload I was having trouble with before has a video of just over 18MB, and is working fine for me now without me even touching the video. So if your video was already okay, I don't see why you would need to reencode it now.
The upload I was having trouble with before has a video of just over 18MB, and is working fine for me now without me even touching the video. So if your video was already okay, I don't see why you would need to reencode it now.