The old large file is likely still part of your local Git history and as you know, the whole history of the branch is pushed.
You'll need to make sure it isn't in an earlier commit either, eg by reset
ing back to a commit where the video isn't there, then committing only the new smaller one.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…