FFmpeg: Creating sterographic video from a 2D source / Witchboard (1988)


This is further study in the creation of depth information based on two-dimensional source material http://oioiiooixiii.blogspot.com/2014/02/an-experiment-in-creating-three.html

By slighting delaying the video entering one eye, the interference created can reveal a sense of depth to parts of the scene.

This video above loops between two versions of the same two scenes. One has a three frame differential (24/8 = 0.125) and the other, eight (24/3 = 0.3). Depending on content and movement, the greater the time difference, the clearer the effect works.

The video was created with FFmpeg, and the ffplay command, with filterchain, is given below:

# 'setpts=PTS+0.3/TB' delay video start by 0.3 seconds

ffplay \
   -i witchcraft.mp4 \
   -vf \
      "scale=320x180,split [a][b];\
      nullsrc=size=640x180[base];\
      [a] setpts=PTS-STARTPTS [left];\
      [b] setpts=PTS+0.3/TB [right];\
      [base][left]overlay=shortest=1[x];\
      [x][right]overlay=x=320:shortest=1"\
   -loop 0


The source video was taken from "Witchboard", a cheesy, but enjoyable, 1980's horror film (big hair, and all that).



ffmpeg setpts: https://ffmpeg.org/ffmpeg-filters.html#setpts_002c-asetpts
imdb: http://www.imdb.com/title/tt0090327/