AudioListener.getInput()

The getInput() method of the AudioListener class in three.js returns the Web Audio API AnalyserNode that is connected to the input of the AudioListener.

Syntax

AudioListener.getInput()

Return Value

The getInput() method returns an instance of the AnalyserNode Web Audio API interface.

Usage

The getInput() method is used to retrieve the AnalyserNode that is connected to the input of the AudioListener. This node can be used to perform real-time frequency analysis on the audio signal that is being received by the listener.

const listener = new THREE.AudioListener();
const analyser = listener.getInput();

// Connect an audio source to the listener
const audio = new THREE.Audio( listener );
const loader = new THREE.AudioLoader();
loader.load( 'path/to/audio.mp3', function( buffer ) {
    audio.setBuffer( buffer );
    audio.play();
});

// Perform real-time frequency analysis on the input signal
const dataArray = new Float32Array( analyser.frequencyBinCount );
analyser.getFloatFrequencyData(dataArray);

Example

In this example, we create an AudioListener and retrieve the AnalyserNode for real-time frequency analysis. We then load an audio file and connect it to the listener. Finally, we use the AnalyserNode to animate a mesh based on the audio frequency data.

const listener = new THREE.AudioListener();
const analyser = listener.getInput();
const audio = new THREE.Audio( listener );
const loader = new THREE.AudioLoader();
loader.load( 'path/to/audio.mp3', function( buffer ) {
    audio.setBuffer( buffer );
    audio.play();
});

const geometry = new THREE.BoxBufferGeometry( 1, 1, 1 );
const material = new THREE.MeshStandardMaterial({ color: 0xffffff });
const mesh = new THREE.Mesh( geometry, material );
scene.add( mesh );

const dataArray = new Float32Array( analyser.frequencyBinCount );
const animate = function () {
    requestAnimationFrame( animate );
    analyser.getFloatFrequencyData(dataArray);
    
    const frequency = dataArray[0] || 0;
    mesh.scale.set( 1+frequency/100, 1+frequency/100, 1+frequency/100 );
    mesh.rotation.x += 0.01;
    mesh.rotation.y += 0.01;
    renderer.render( scene, camera );
};
animate();

Browser Compatibility

The getInput() method is supported in all modern browsers that support the Web Audio API.

Conclusion

The getInput() method of the AudioListener class in three.js is used to retrieve the AnalyserNode that is connected to the input of the listener. This node can be used to perform real-time frequency analysis on the audio signal that is being received by the listener.