raw-YUV to MP4 with pipe

rawvideo-pipe.rb

command = "ffmpeg -f rawvideo -pix_fmt yuv444p -color_range 2 -s:v 160x120 -r 30 -i pipe:0 "
        + "-c:v libx264 -profile:v baseline -pix_fmt yuv420p -y output.mp4"
IO.popen(command, "r+"){|io|
  io.close_read
  100.times do
    (0..255).map{|y|
      image  = ([y].pack("C")) * 160 * 120
      image += ([127].pack("C")) * 160 * 120
      image += ([127].pack("C")) * 160 * 120
      15.times do
        io.write image
      end
    }
  end
  io.close
}