Date: 2016sep23 Product: ffmpeg Keywords: rotate 90 Q. How to I fix a sideways video? A. Use the ffmpeg like this:

ffmpeg -i myvideo_in.mp4 -vf "transpose=2" myvideo_fixed.mp4

This works for Samsung Galaxy 5 mini landscape videos - that show up sideways on Windows. transpose=2 is 90 degrees counter clockwise