Remove flickering due to artificial light with ffmpeg
The following worked well for me, based on the same ideas

http://www.premiumbeat.com/blog/quick-trick-for-de-flickering-your-video-shots/

https://superuser.com/questions/1025794/merge-two-videos-with-transparency-in-ffmpeg

It's more than a year, so I don't remember exactly how I arrived at this. The VOB was a video shot from a projected screen with serious projector pulldown flicker, alternating lighter and darker frames. The VOB was interlaced at 29.970 fps, where 1 frame would be 0.033 sec. The result was amazingly good, way beyond what I could get with various other deflicker filters.

ffmpeg -fflags +genpts -i FLICKER.VOB -fflags +genpts -i FLICKER.VOB -filter_complex "[0:v]setpts=PTS-STARTPTS[top]; [1:v]setpts=PTS-STARTPTS+.033/TB, format=yuva420p, colorchannelmixer=aa=0.5[bottom]; [top][bottom]overlay=shortest=1" -c:v libx264 -crf 26 -an NOFLICKER.mp4