bk2_to_dem.lua

local inputlabels = {"A", "B", "Select", "Start", "Right", "Left", "Up", "Down"}

function getinputbyte()
  if not movie.isloaded() then
    return 0
  end

  local t = movie.getinput(emu.framecount())
  local b = 0

  for i = 0, 7 do
    if t[inputlabels[i + 1]] then
      b = b + bit.lshift(1, i)
    end
  end

  return b
end

function tryinput(file)
	local input = getinputbyte()
	file:write(string.char(input))
    lastinput = input
end

local demo = io.open("bgb.dem", "wb")
local lastinput = -1

function luabad()
	tryinput(demo)
end

local vblank = 0x0040
event.onmemoryexecute(luabad, vblank)

while emu.framecount() <= movie.length() do
	emu.frameadvance()
end

demo:close()

client.pause()