setValueAtTime() метод интерфейса AudioParam (en-US) позволяющий мгновенно точно по времени изменять значение AudioParam , сравнивая с AudioContext.currentTime. Новое значение даётся в значении параметра.


var AudioParam = AudioParam.setValueAtTime(value, startTime)



Число с плавающей точкой представляет значение AudioParam изменяемое в данное время.


A double representing the time (in seconds) after the AudioContext was first created that the change in value will happen. A TypeError is thrown if this value is negative.


A reference to this AudioParam object. In some browsers older implementations of this interface return void.


This simple example features a media element source with two control buttons (see our webaudio-examples repo for the source code, or view the example live). When the buttons are pressed, the currGain variable is incremented/decremented by 0.25, then the setValueAtTime() method is used to set the gain value equal to currGain, one second from now (audioCtx.currentTime + 1.)

// create audio context
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();

// set basic variables for example
var myAudio = document.querySelector("audio");
var pre = document.querySelector("pre");
var myScript = document.querySelector("script");

pre.innerHTML = myScript.innerHTML;

var targetAtTimePlus = document.querySelector(".set-target-at-time-plus");
var targetAtTimeMinus = document.querySelector(".set-target-at-time-minus");

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

// Create a gain node and set it's gain value to 0.5
var gainNode = audioCtx.createGain();
gainNode.gain.value = 0.5;
var currGain = gainNode.gain.value;

// connect the AudioBufferSourceNode to the gainNode
// and the gainNode to the destination

// set buttons to do something onclick
targetAtTimePlus.onclick = function () {
  currGain += 0.25;
  gainNode.gain.setValueAtTime(currGain, audioCtx.currentTime + 1);

targetAtTimeMinus.onclick = function () {
  currGain -= 0.25;
  gainNode.gain.setValueAtTime(currGain, audioCtx.currentTime + 1);


Web Audio API
# dom-audioparam-setvalueattime

Совместимость с браузерами

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See also