A pure Lua implementation to read midi files using a callback function.

The library allows not only reading all tracks in a midi file at once, but also reading only the header (e.g. to a find out the track count) and then reading a single, specific midi track.

Reading all tracks in a midi file:

local midi = require "midi"

local file = assert(io.open("short-tune.mid"))
midi.process(file, print)

file:close()

Reading only the last track in a midi file:

local midi = require "midi"

local file = assert(io.open("short-tune.mid"))
local tracks = midi.processHeader(file) -- find number of tracks

file:seek("set") -- seek back to the beginning of the file
midi.processTrack(file, print, tracks)

file:close()

The library consists of a single Lua file, namely midi.lua.

The following functions require a stream of a real midi file and use a callback to report individual midi events:

function midi.process(stream, callback, onlyHeader, onlyTrack)
function midi.processHeader(stream, callback)
function midi.processTrack(stream, callback, track)

All functions return the total number of tracks in the midi file.

The following function simply reads a single midi event (excluding the usually preceeding delta-time) from the given stream:

function midi.processEvent(stream, callback, runningStatus)

It returns how many bytes it had to read from the stream, followed by the updated runningStatus.

Prints all midi events in the given midi file.

Prints only the midi events of a single track in the midi file.

Handles only specific midi events using a dispatch table.

Lists the signatures, on how the callback is invoked, for each midi event.

Shows how to read single events from a stream.