StereoPannerNode - Web APIs 编辑

The StereoPannerNode interface of the Web Audio API represents a simple stereo panner node that can be used to pan an audio stream left or right. It is an AudioNode audio-processing module that positions an incoming audio stream in a stereo image using a low-cost equal-power panning algorithm.

The pan property takes a unitless value between -1 (full left pan) and 1 (full right pan). This interface was introduced as a much simpler way to apply a simple panning effect than having to use a full PannerNode.

Constructor

StereoPannerNode()

Creates a new instance of a StereoPannerNode object.

Properties

Inherits properties from its parent, AudioNode.

StereoPannerNode.pan Read only

Is an a-rate AudioParam representing the amount of panning to apply.

Methods

No specific method; inherits methods from its parent, AudioNode.

Example

In our StereoPannerNode example (see source code) HTML we have a simple <audio> element along with a slider <input> to increase and decrease pan value. In the JavaScript we create a MediaElementAudioSourceNode and a StereoPannerNode, and connect the two together using the connect()method. We then use an oninput event handler to change the value of the StereoPannerNode.pan parameter and update the pan value display when the slider is moved.

Moving the slider left and right while the music is playing pans the music across to the left and right speakers of the output, respectively.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var myAudio = document.querySelector('audio');

var panControl = document.querySelector('.panning-control');
var panValue = document.querySelector('.panning-value');

pre.innerHTML = myScript.innerHTML;

// Create a MediaElementAudioSourceNode
// Feed the HTMLMediaElement into it
var source = audioCtx.createMediaElementSource(myAudio);

// Create a stereo panner
var panNode = audioCtx.createStereoPanner();

// Event handler function to increase panning to the right and left
// when the slider is moved

panControl.oninput = function() {
  panNode.pan.setValueAtTime(panControl.value, audioCtx.currentTime);
  panValue.innerHTML = panControl.value;
}

// connect the MediaElementAudioSourceNode to the panNode
// and the panNode to the destination, so we can play the
// music and adjust the panning using the controls
source.connect(panNode);
panNode.connect(audioCtx.destination);

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Using the Web Audio API