Rotate / Flip video on Linux with ffmpeg

1. Flip video vertically:

ffmpeg -i INPUT -vf vflip -c:a copy OUTPUT

2. Flip video horizontally:

ffmpeg -i INPUT -vf hflip -c:a copy OUTPUT

3. Rotate 90 degrees clockwise:

ffmpeg -i INPUT -vf transpose=1 -c:a copy OUTPUT

4. Rotate 90 degrees counterclockwise:

ffmpeg -i INPUT -vf transpose=2 -c:a copy OUTPUT