title: ffmpeg auto dection portrait then do the necessary flip
body: <p>Is it possible to have ffmpeg detect the video size, and if it's not landscape, have it do the rotate to 90 degress clockwise? I have found an article here, but am not sure if it can detect this automatically or not: <a href="https://stackoverflow.com/questions/3937387/rotating-videos-with-ffmpeg">Rotating videos with FFmpeg</a></p>