make triangles for hexoscope

maketriangles.sh

  #!/bin/bash
mkdir frames
ffmpeg -i $1 -f image2 frames/image-%4d.png
convert -size 1280x720 xc:black \
        -fill white \
        -stroke none \
        -draw "path 'M 640 0 L 224 720 L 1055 720 z' "   \
        mask.gif

# rotate it (optional)
mogrify -rotate 180 mask.gif       

for i in frames/* 
do
    if test -f "$i" 
    then
       echo "converting $i to ${i//image/tri}"
       #echo "to ${i//image/tri}"
       convert $i mask.gif -alpha Off -compose CopyOpacity -composite -rotate 180 -crop 830x720+224+0 ${i//image/tri}
    fi
done

#ffmpeg -f image2 -i output-%4d.png -pix_fmt yuv420p -r 30 output_whole.mov
## trim da music
#ffmpeg -i Bonehead.mp3 -ss 0 -t 75 musicshort2.wav
# add the music
#ffmpeg -i musicshort2.wav -i output_whole.mov final_whole.mov