Generation/handling of movies (in Unix environment)
Using ffmpeg it is possible to merge two movies and display them simultaneously
ffmpeg -i movie_1.avi -i movie_2.avi -filter_complex '[0:v]pad=iw*2:ih[int];[int][1:v]overlay=W/2:0[vid]' -map [vid] -c:v libx264 -crf 23 -preset veryfast output_movie.avi