N64: Added a lua script to try and play M64 format movies

BizHawk.MultiClient/output/Lua/N64/M64_reader.lua

@@ -0,0 +1,145 @@
+-- M64 reader script
+-- Translates M64 file movies into button presses for Bizhawk, accounting for lag frames.
+-- This script will automatically pause at the end of the movie
+
+-- This script will not clear the saveram. If a movie requires empty saveram it must be cleared before using this script.
+
+-- If you are trying to convert a M64 into BKM format, you can try pausing the emulator and starting recording a movie, then loading this script and letting it run. Beginning a new movie will clear the saveram for you.
+
+
+-- Change this filename to be the .m64 file you want to play. Lua will look for the movie file right next to this script unless a directory location is given.
+local m64_filename = "CHANGE_ME.m64"
+
+
+-- Open the file and read past the header data
+local input_file = assert(io.open(m64_filename, "rb"))
+local data = input_file:read(0x400)
+
+-- Flag to note that we've reached the end of the movie
+local finished = false
+
+-- Since m64 movies do not record on lag frames, we need to know if the input was actually used for the current frame
+local input_was_used = false
+function input_used()
+	if not finished then
+   input_was_used = true
+  end
+end
+event.oninputpoll(input_used)
+
+local buttons = { }
+local X
+local Y
+-- Reads in the next frame of data from the movie, or sets the finished flag if no frames are left
+function read_next_frame()
+  data = input_file:read(4)
+  if not data then 
+    finished = true
+    return
+  end
+  local byte = string.byte(string.sub(data,1,1))
+  if bit.band(byte,0x01) ~= 0 then
+    buttons["DPad R"] = true
+  else
+    buttons["DPad R"] = false
+  end
+  if bit.band(byte,0x02) ~= 0 then
+    buttons["DPad L"] = true
+  else
+    buttons["DPad L"] = false
+  end
+  if bit.band(byte,0x04) ~= 0 then
+    buttons["DPad D"] = true
+  else
+    buttons["DPad D"] = false
+  end
+  if bit.band(byte,0x08) ~= 0 then
+    buttons["DPad U"] = true
+  else
+    buttons["DPad U"] = false
+  end
+  if bit.band(byte,0x10) ~= 0 then
+    buttons["Start"] = true
+  else
+    buttons["Start"] = false
+  end
+  if bit.band(byte,0x20) ~= 0 then
+    buttons["Z"] = true
+  else
+    buttons["Z"] = false
+  end
+  if bit.band(byte,0x40) ~= 0 then
+    buttons["B"] = true
+  else
+    buttons["B"] = false
+  end
+  if bit.band(byte,0x80) ~= 0 then
+    buttons["A"] = true
+  else
+    buttons["A"] = false
+  end
+  
+  byte = string.byte(string.sub(data,2,2))
+  if bit.band(byte,0x01) ~= 0 then
+    buttons["C Right"] = true
+  else
+    buttons["C Right"] = false
+  end
+  if bit.band(byte,0x02) ~= 0 then
+    buttons["C Left"] = true
+  else
+    buttons["C Left"] = false
+  end
+  if bit.band(byte,0x04) ~= 0 then
+    buttons["C Down"] = true
+  else
+    buttons["C Down"] = false
+  end
+  if bit.band(byte,0x08) ~= 0 then
+    buttons["C Up"] = true
+  else
+    buttons["C Up"] = false
+  end
+  if bit.band(byte,0x10) ~= 0 then
+    buttons["R"] = true
+  else
+    buttons["R"] = false
+  end
+  if bit.band(byte,0x20) ~= 0 then
+    buttons["L"] = true
+  else
+    buttons["L"] = false
+  end
+  
+  X = string.byte(string.sub(data,3,3))
+  if X > 127 then
+    X = X - 256
+  end
+  
+  Y = string.byte(string.sub(data,4,4))
+  if Y > 127 then
+    Y = Y - 256
+  end
+end
+
+while true do
+  -- Only read the next frame of data if the last one was used
+  if input_was_used and not finished then
+    read_next_frame()
+    input_was_used = false
+  end
+  
+  if not finished then
+    joypad.set(buttons, 1)
+    local analogs = { ["X Axis"] = X, ["Y Axis"] = Y }
+    joypad.setanalog(analogs, 1)
+  end
+  
+  if finished then
+    console.output("done!")
+    emu.pause()
+  end
+  
+  emu.frameadvance()
+end
+