The MP4 that comes out of a meeting
Zoom, Meet and Teams hand you an MP4 when you record a call, and they're among the files that come out best: each person speaks into their own microphone, there's no room noise, and voices overlap far less than they do in a room. If you recorded with separate tracks as well, speaker separation gets it right nearly every time.
Size is the only surprise: an hour of meeting recorded in high definition easily reaches two or three gigabytes because of the picture, which isn't used here for anything. You can upload it as it is — the limit is 10 GB — or pull the audio out first, which leaves you with about 50 MB.