On Linux, you should have ffmpeg tool and libraries installed on your system.
Original post here:
Rotate 90 clockwise:
ffmpeg -i in.mov -vf "transpose=1" out.mov
For the transpose parameter you can pass:
0 = 90 Counter CLockwise and Vertical Flip (default) 1 = 90 Clockwise 2 = 90 Counter Clockwise 3 = 90 Clockwise and Vertical Flip