Little program to spacially concatenate n video sequences to a single one with captions. I used this to visualize differences between different trackers.
usage: video_writer -d /path/to/images1/%08d.jpg -c VIDEO1_CAPTION -d /path/to/images2/%08d.jpg -c VIDEO2_CAPTION -d /path/to/images3/%08d.jpg -c VIDEO3_CAPTION -o /path/to/output/dir/