I created a script to do a side-by-side comparison between videos recorded with my two action cameras: a new SJCAM 8 Pro and the old Xiaomi Yi.

The result is a video like the following: the central part of each video is stacked horizontally on the final video, two labels are overlayed on the bottom corners, the audio from the first video is mixed into the left channel of the resulting video and the audio from the second video goes to the right channel.