oioiiooixiii: FFmpeg chromakey filter / Filthy Frank

Colour keying was available in FFmpeg since 2.8, but a 'chromakey' filter was included with the recent release of version 3.0. https://twitter.com/oioiiooixiii/status/704052912687878144

# Basic FFmpeg chromakey filter command - see also: 'colorkey'

ffmpeg \
   -i baselayer.mkv \
   -i overlay.mkv \
   -filter_complex \
      "[1:v]chromakey=green:0.1:0.5[keyed];\
       [0:v][keyed]overlay[out]" \
   -map "[out]" \
   output.mkv

100 layers of "Filthy Frank"

info: https://ffmpeg.org/ffmpeg-filters.html#chromakey
further info: https://ffmpeg.org/ffmpeg-filters.html#colorkey
source video: http://www.filthyfrank.net/