Rotate your video with ffmpeg

You might run into an issue with the orientation on your videos at times and yeah it is super easy to rotate your video with a free and open source utility ffmpeg.

Here is how :

ffmpeg -i input.mp4 -vf "transpose=1" output.mp4

Where

0=90 Degrees Counter Clockwise.

1=90 degrees Clockwise

2=90 degrees Counter Clockwise

3=90 degrees Clockwise