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function love.update(dt) local current_time = love.timer.getTime() - start_time -- Iterate through events within a tolerance while song_data.tracks[1].events[current_event] and song_data.tracks[1].events[current_event].time <= current_time do local ev = song_data.tracks[1].events[current_event] if ev.type == "note_on" then play_sound(ev.note, ev.velocity) end current_event = current_event + 1 end end The basic note list is useful, but the best midi2lua converters offer sophisticated features. 1. Time Conversion (Ticks to Seconds) MIDI is based on Ticks (Pulses Per Quarter Note). Games run on real-time seconds. A good midi2lua script will parse the Set Tempo meta-events (Microseconds per quarter note) and pre-calculate the absolute time in seconds for every event. 2. Compression via Delta Encoding Large MIDI files can generate huge Lua tables. Advanced converters use Delta Time (time since last event) instead of absolute time. This reduces file size significantly because integers are smaller.
This article will explore what midi2lua is, why it matters, how to use it effectively, and advanced techniques to optimize your output. At its core, midi2lua is a parser and converter. It takes a binary Standard MIDI File ( .mid ) and translates it into a human-readable (and machine-executable) Lua table. midi2lua
It transforms your DAW (Digital Audio Workstation) into a level editor for sound. While it requires understanding time management in Lua (love.update, heartbeat, or RenderStepped), the payoff is a perfectly synchronized audio-visual experience. function love
with open(output_path, 'w') as f: f.write(lua_table) midi_to_lua("input.mid", "output.lua") If you are building a game with complex musical timing, a rhythm game mod, or an interactive art piece in a Lua environment, manually typing timestamps into arrays is madness. midi2lua automates the tedious translation of musical creativity into functional code. Games run on real-time seconds
-- During conversion if program_change == 1 then instrument = "acoustic_grand_piano" end Even with a great tool, midi2lua conversions can fail silently. Here is what to watch for. The "Zero Duration" Bug Many DAWs export note-off velocity at the exact same tick as the next note-on. In Lua, iterating through this can trigger a note-on and note-off in the same frame, causing "clicks" or silent notes. Fix: Add a minimum duration filter (e.g., ignore notes shorter than 10ms). Floating Point Precision Lua uses double-precision floats, but MIDI clocks are integer ticks. When you convert ticks to seconds, you may get numbers like 0.3333333333 . When checking if current_time == event_time in your game loop, it will fail . Always use >= or subtract a small epsilon (e.g., 0.001 ). Memory Bloat A 5-minute MIDI file with dense drum patterns might contain 20,000+ events. Loading the entire Lua table into memory is fine for PC games but may crash a Roblox server or an embedded device. Fix: Use a streaming approach where midi2lua splits the song into chunks (bars 1-16, 17-32) that you load dynamically. Building Your Own midi2lua in Python If existing tools don't fit your Lua dialect (e.g., you need { } vs Lua tables, or you need GMod specific syntax), writing your own midi2lua is surprisingly simple using the mido library.
-- Good for compression { delta = 100, note = 60 } { delta = 200, note = 64 } If you are converting for a specific video game soundfont (like a ROM hacker), you can map MIDI Program Changes (Patch numbers) to specific Lua sound function calls.
local song_data = require("my_song") function love.load() current_event = 1 start_time = love.timer.getTime() end
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