AudioContext.createDelay()
createDelay()
是 AudioContext
的一个方法,作用是将输入音频信号延迟一定时间。(比如可以实现 对着话筒说句话,然后几秒后 这句话从音响里播放出来)
语法
js
var audioCtx = new AudioContext();
var synthDelay = audioCtx.createDelay(maxDelayTime);
参数
- maxDelayTime
-
设置最大允许延迟的时间,以“秒”为单位
返回
A DelayNode
(en-US). The default DelayNode.delayTime
(en-US) if no parameter is passed to createDelay()
is 0 seconds.
以上是原文,大意是返回延时时间,没有设置时默认是 0
示例
首先是中文版的简洁的示例,这个例子中话筒里接收到的声音会延迟 3 秒从音响中播放。
window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext || window.msAudioContext; try {//音频相关api var audioContext = new window.AudioContext(); var synthDelay = audioContext.createDelay(5.0); } catch (e) { alert("你浏览器不支持"); } var error = function (error) {alert("有错误"); }; //以下是获取麦克风 if (navigator.getUserMedia) { //标准api navigator.getUserMedia({ "audio": true }, function (stream) { micto(stream); //具体工作 }, error); }else if(navigator.webkitGetUserMedia) { //webkit api navigator.webkitGetUserMedia({audio:true, video: false }, function (stream) { micto(stream); //具体工作 }, error); }else if (navigator.mozGetUserMedia) { //火狐 api navigator.mozGetUserMedia({ "audio": true }, function (stream) { micto(stream);//具体工作 }, error); }else if (navigator.msGetUserMedia) { //ie api navigator.msGetUserMedia({ "audio": true }, function (stream) { micto(stream);//具体工作 }, error); } else { alert("你的浏览器版不支持这个api"); } var micto = function(stream) { synthDelay.delayTime.value = 3.0; //延迟3秒 var source = audioContext.createMediaStreamSource(stream); source.connect(synthDelay); synthDelay.connect(audioContext.destination); }
以下是英文版示例
We have created a simple example that allows you to play three different samples on a constant loop — see create-delay (you can also view the source code). If you just press the play buttons, the loops will start immediately; if you slide the sliders up to the right, then press the play buttons, a delay will be introduced, so the looping sounds don't start playing for a short amount of time.
js
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();
var synthDelay = audioCtx.createDelay(5.0);
...
var synthSource;
playSynth.onclick = function() {
synthSource = audioCtx.createBufferSource();
synthSource.buffer = buffers[2];
synthSource.loop = true;
synthSource.start();
synthSource.connect(synthDelay);
synthDelay.connect(destination);
this.setAttribute('disabled', 'disabled');
}
stopSynth.onclick = function() {
synthSource.disconnect(synthDelay);
synthDelay.disconnect(destination);
synthSource.stop();
playSynth.removeAttribute('disabled');
}
...
var delay1;
rangeSynth.oninput = function() {
delay1 = rangeSynth.value;
synthDelay.delayTime.value = delay1;
}
Specifications
Specification |
---|
Web Audio API # dom-baseaudiocontext-createdelay |
Browser compatibility
BCD tables only load in the browser