Minecraft .nbs player

function loadAPIS()

    --[[
        Implementing apis
        - TheModerGuy
    --]]

    local function yield()
        os.queueEvent("fake")
        os.pullEvent("fake")
    end

    -- read short integer (16-bit) from file
    local function readShort(file)
        return file.read() + file.read() * 256
    end

    -- read integer (32-bit) from file
    local function readInt(file)
        return file.read() + file.read() * 256 + file.read() * 65536 + file.read() * 16777216
    end

    -- read string from file
    local function readString(file)
        local s = ""
        local len = readInt(file)
        for i = 1, len do
            local c = file.read()
            if not c then
                break
            end
            s = s..string.char(c)
        end
        return s
    end

    -- read nbs file header
    local function readNBSHeader(file)
        local header = {}
        header.lenght = readShort(file)
        header.height = readShort(file)
        header.name = readString(file)
        if header.name == "" then
            header.name = "Untitled"
        end
        header.author = readString(file)
        if header.author == "" then
            header.author = "Unknown"
        end
        header.original_author = readString(file)
        if header.original_author == "" then
            header.original_author = "Unknown"
        end
        header.description = readString(file)
        header.tempo = readShort(file) / 100
        header.autosave = file.read()
        header.autosave_duration = file.read()
        header.time_signature = file.read()
        header.minutes_spent = readInt(file)
        header.left_clicks = readInt(file)
        header.right_clicks = readInt(file)
        header.blocks_added = readInt(file)
        header.blocks_removed = readInt(file)
        header.filename = readString(file)
        return header
    end

    -- jump to the next tick in the file
    local function nextTick(file, tSong)
        local jump = readShort(file)
        for i = 1, jump - 1 do
            table.insert(tSong, {})
        end
        return jump > 0
    end

    -- read the notes in a tick
    local function readTick(file)
        local t = {}
        local jump = readShort(file)
        while jump > 0 do
            local instrument = file.read() + 1
            if instrument > 5 then
                return nil, "Can't convert custom instruments"
            end
            local note = file.read() - 33
            if note < 0 or note > 24 then
                return nil, "Notes must be in Minecraft's 2 octaves"
            end
            if not t[instrument] then
                t[instrument] = {}
            end
            table.insert(t[instrument], note)
            jump = readShort(file)
        end
        return t
    end

    -- API functions

    -- save a converted song to a file
    function nbsSaveSong(tSong, sPath)
        local file = fs.open(sPath, "w")
        if file then
            file.write(textutils.serialize(tSong))
            file.close()
            return true
        end
        return false, "Error opening file "..sPath
    end

    -- load and convert an .nbs file and save it
    function nbsLoad(sPath, bVerbose)
        local file = fs.open(sPath, "rb")
        if file then
            if bVerbose then
                print("Reading header...")
            end
            local tSong = {}
            local header = readNBSHeader(file)
            tSong.name = header.name
            tSong.author = header.author
            tSong.original_author = header.original_author
            tSong.lenght = header.lenght / header.tempo
            tSong.delay = 1 / header.tempo
            if bVerbose then
                print("Reading ticks...")
            end
            while nextTick(file, tSong) do
                local tick, err = readTick(file, tSong)
                if tick then
                    table.insert(tSong, tick)
                else
                    file.close()
                    return nil, err
                end
                yield()
            end
            file.close()
            return tSong
        end
        return nil, "Error opening file "..sPath
    end

    local total = 0;
    local slept = 0;
    local function _round(_i)
      _i = _i * 20;
      if _i >= 0 then
        return math.floor(_i+.5) / 20
      else
        return math.ceil(_i-.5) / 20
      end
    end
    function atsWait(_sleep)
      if _sleep < 0 then return end
      total = total + _sleep;
      _sleep = _round(_sleep);
      slept = slept + _sleep;
      if (slept - total) >= 0.05 then
        _sleep = _sleep - 0.05;
        slept = slept - 0.05;
      elseif (slept - total) < -0.05 then
        _sleep = _sleep + 0.05;
        slept = slept + 0.05;
      end
      sleep(_sleep);
    end
end

local args = {...} -- args table

if args[2]~= nil then
    loop=args[2]
end

loadAPIS()

local played,played2=true,true
local delay,lenght
local side,textColor,bgColor,notesPlayed,row=0,1,2,0,0

local notenames = {"F#3"," G3","G#3"," A3","A#3"," B3",
" C4","C#4"," D4","D#4"," E4"," F4","F#4"," G4",
"G#4"," A4","A#4"," B4"," C5","C#5"," D5","D#5",
" E5"," F5","F#5"}
local instnames = {"PIANO","BASS DRUM","SNARE","CLICKS",
"BASS GUITAR"}

-- ID is the NoteBlock ID to use
local id=1
-- Modem stuff
function getSide()
    for n,side in pairs(rs.getSides()) do
      if peripheral.getType( side )=="modem" then
        return side
      end
    end
end
rednet.open(getSide())
local MODEM = peripheral.wrap(getSide())
local PERIPHERALS = MODEM.getNamesRemote()
local maxId = #(MODEM.getNamesRemote())

local function play(inst,note)

  if inst==1 then
    inst=0
  elseif inst==2 then
    inst=4
  elseif inst==3 then
    inst=1
  elseif inst==4 then
    inst=2
  elseif inst==5 then
    inst=3
  end

  id = id > maxId and 1 or id

  textColor = textColor * (textColor == bgColor and 2 or 1)

  textColor = textColor >= colors.black and 1 or textColor

  MODEM.callRemote(PERIPHERALS[id],"playNote",inst,note)

  local str = instnames[inst+1] .." "..notenames[note+1]
  local str = instnames[inst+1] .." "..notenames[note+1]


  id = id + 1
  notesPlayed = notesPlayed + 1
end


local function load(file)
  local tSong = nbsLoad(file)
  delay = tSong.delay
  lenght = tSong.lenght
  realLenght = lenght * (1/delay)

  for a,b in pairs(tSong) do
    if type(b)=="table" then
      for inst,d in pairs(b) do

        for e,note in pairs(d) do

          play(inst,note)
        end

        played2=true
      end

      if played2==true then
        played=true
        played2=false
      end

      atsWait(delay)
      row = row + 1

      if rs.getInput("front") then
        return
      end
    end
  end
end

while true do

    id,msg,dist = rednet.receive()
    data = string.gmatch(msg, "%S+")
    if data(1) == "Player" then
        print("Me")

        if data(2)== "Play" then

            InFile = data(3)
            print("Play")
            load(tostring(InFile))

            rednet.broadcast("DJ DONE")

        end

        if data(2)=="Util" then

        print("Util")

            shell.run(tostring(data(3)))

        end

    end

end