#!/bin/bash

rm -r build
mkdir build
convert -size 640x480 -depth 24 canvas:black png24:build/black.png 
convert -size 640x480 -depth 24 canvas:white png24:build/white.png

mkdir build/anim

for ((a=0; $a < 1000; a=$a+2)); do
    ln -s ../black.png build/anim/$a.png
done

for ((a=1; $a < 1000; a=$a+2)); do
    ln -s ../white.png build/anim/$a.png 
done

mencoder "mf://build/anim/*.png" -v -vf-clr -mf fps=60 -o build/output.avi -ovc lavc