The browser reports such a video by its shown size and ffmpeg's crop counts stored pixels, so a
frame over the middle half of a 320 stored, 640 shown video kept the whole width. A crop now carries
the size it was measured on and is scaled to the file's own pixels. A spec from before it did is cut
as it always was. Also drops a stale note in downloads/quota.py: edit jobs are held to the cap.