https://github.com/patrickroberts/synth-js

JavaScript MIDI-to-WAV synthesizer
https://github.com/patrickroberts/synth-js

command-line-tool javascript midi-parser node-module wav-files

Last synced: about 1 month ago
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JavaScript MIDI-to-WAV synthesizer

• Host: GitHub
• URL: https://github.com/patrickroberts/synth-js
• Owner: patrickroberts
• License: mit
• Created: 2017-05-04T07:39:05.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2023-04-01T10:36:22.000Z (almost 2 years ago)
• Last Synced: 2024-10-06T23:45:30.427Z (3 months ago)
• Topics: command-line-tool, javascript, midi-parser, node-module, wav-files
• Language: JavaScript
• Size: 89.8 KB
• Stars: 37
• Watchers: 5
• Forks: 6
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# synth-js

Command-line utility and Node module for generating raw audio data from MIDI files.

## Installation

### Command-line utility:

```bash

$ npm link synth-js

```

### Node module:

```bash

$ npm install --save synth-js

```

### JavaScript:

```html

```

After including the file from `dst/synth.min.js`, the global variable `synth` will be initialized.

## Usage

### Command-line utility:

```bash

# assuming song.mid in cwd

$ synth -i song

# now song.wav contains raw audio data for song.mid

```

### Node module:

```js

const synth = require('synth-js');

const fs = require('fs');

let midBuffer = fs.readFileSync('song.mid');

// convert midi buffer to wav buffer

let wavBuffer = synth.midiToWav(midiBuffer).toBuffer();

fs.writeFileSync('song.wav', wavBuffer, {encoding: 'binary'});

```

### JavaScript:

```html

  #wav:after {

    content: " " attr(download);

  }

  #wav:not([href]) {

    display: none;

  }

Download

  var audio;

  var input = document.getElementById('midi');

  var anchor = document.getElementById('wav');

  input.addEventListener('change', function change() {

    // clean up previous song, if any

    if (anchor.hasAttribute('href')) {

      URL.revokeObjectURL(anchor.href);

      anchor.removeAttribute('href');

      if (audio && !audio.paused) {

        audio.pause();

      }

    }

    // check if file exists

    if (input.files.length > 0) {

      var reader = new FileReader();

      var midName = input.files[0].name;

      // replace file extension with .wav

      var wavName = midName.replace(/\..+?$/, '.wav');

      // set callback for array buffer

      reader.addEventListener('load', function load(event) {

        // convert midi arraybuffer to wav blob

        var wav = synth.midiToWav(event.target.result).toBlob();

        // create a temporary URL to the wav file

        var src = URL.createObjectURL(wav);

        audio = new Audio(src);

        audio.play();

        anchor.setAttribute('href', src);

      });

      // read the file as an array buffer

      reader.readAsArrayBuffer(input.files[0]);

      // set the name of the wav file

      anchor.setAttribute('download', wavName);

    }

  });

```

See the demo [here][browser-demo].

## FAQ

### Where can I find documentation?

Currently, documentation only exists for the command-line utility.

To access it, use `man`:

```bash

$ man synth

```

For Node or JavaScript, refer to the `src/` directory for accessible APIs:

* `synth.WAV()`

* `synth.MIDIStream()`

* `synth.midiToWav()`

## License

Available under the MIT License

[browser-demo]: https://jsfiddle.net/patrob10114/o5r1adyz/show/