MidiParser is a Javascript Binary MIDI file reader for the browser and Node which converts a MIDI binary data structure to a JSON object, making it much easier to iterate over and interact with.
- Tiny and dependency free
- Browser & Node Compatible
- Supported data input :
BASE64
encoded Midi dataUINT8
arrayBuffer, obtained when reading or fetching a .mid binary.FileInput Element
in the Browser
- Custom Midi Messages
A simple example parsing a MIDI file in Node ...
let midiParser = require('midi-parser-js');
let fs = require('fs')
// read a .mid binary (as base64)
fs.readFile('./test.mid', 'base64', function (err,data) {
// Parse the obtainer base64 string ...
var midiArray = midiParser.parse(data);
// done!
console.log(midiArray);
});
Example in Browser...
<script type="module">
import MidiParser from 'midi-parser-js'
// select the INPUT element that will handle
// the file selection.
let source = document.getElementById('filereader');
// provide the File source and a callback function
MidiParser.parse( source, function(obj){
console.log(obj);
});
</script>
<input type="file" id="filereader"/>
If you want to see it in action, you can test it Here
MidiParser.parse( input [, callback] );
- input : Accepts any of the supported Data Sources : FileInputElement | uint8Array | base64String
- callback : Callback to be executed when data is parsed. Only required when input is a FileInputElement
.
By default, the library ignores the sysEx, and non-standard messages, simply converting their values to integers (when possible). However you can provide a custom hook function to be executed when any non-standard message is found, and process it by your own, returning the resulting value.
MidiParser.customInterpreter = function( msgType, arrayBuffer, metaEventLength){ /* your code */ }
- msgType : Hex value of the message type
- arrayBuffer : Dataview of the midi data. You have to extract your value/s from it, moving the pointer as needed.
- metaEventLength : A length greater than 0 indicates a received message
If you want the default action to be executed, return false
The returned JSON object contains all the attributes of the MIDI file (format type, time division, track count... ) as properties. The tracks and the MIDI events related to each track are container inside the track
property.
The following JSON object represents a MIDI file with 3 tracks and 4 events in Track 0
outputObject{
....formatType: 0|1|2, // Midi format type
....timeDivision: (int), // song tempo (bpm)
....tracks: (int), // total tracks count
....track: Array[
........[0]: Object{ // TRACK 1!
............event: Array[ // Midi events in track 1
................[0] : Object{ // EVENT 1
....................data: (string),
....................deltaTime: (int),
....................metaType: (int),
....................type: (int)
................},
................[1] : Object{...}, // EVENT 2
................[2] : Object{...}, // EVENT 3
................[3] : Object{...} // EVENT 4
............]
........},
........[1] : Object{...}, // TRACK 2
........[2] : Object{...} // TRACK 3
....]
}
If you want to read the data from Event 2 of Track 0 , you should use the following keypath :
outputObject.track[0].event[2].data;
The following distribution channels are available :
- NPM : Install using the following command :
$ npm install midi-parser-js -s
- GIT : You can clone the repository :
$ git clone https://github.com/colxi/midi-parser-js.git
-ZIP : Or download the package in a ZIP file from
-CDN : Include the latest release of this library in your HTML head using the CDN :
Warning : Not recommended for production enviroments!
<script src="https://colxi.info/midi-parser-js/src/main.js"></script>
This package is shipped with support to Node CommonJS and ES6 Modules. Use the appropiate method accoordintg to your enviroment.
// ES6 Module Import :
import {MidiParser} from './midi-parser.js';
// CommonJS Node Import :
let MidiParser = require('midi-parser-js');
MIDI Binary Encoding Specifications in https://github.com/colxi/midi-parser-js/wiki/MIDI-File-Format-Specifications