Which way to turn it
Rotations are clockwise. If the picture lies on its side with the top pointing left, rotate it 90°. If the top points right, rotate it 270°, which is the same as “rotate left”. A video that is upside down needs 180°.
A horizontal flip makes a mirror image of the picture. It fixes writing that reads backwards in a front-camera recording. A vertical flip turns the picture upside down as a mirror image, which is different from a 180° rotation.