javascript - 如何使使用Web Audio Api创建振荡器节点的功能

我知道这听起来很简单或显而易见，但我无法完成这项工作。

请参阅以下代码段：

ctx = new AudioContext();
gain = ctx.createGain();
gain.connect(ctx.destination);
gain.gain.value = 0.5;


osc1 = ctx.createOscillator();
osc1.connect(gain);
osc1.frequency.value = 450;
osc1.start();
osc1.stop(2);

osc2 = ctx.createOscillator();
osc2.connect(gain);
osc2.frequency.value = 500;
osc2.start();
osc2.stop(2);
console.log("playing");

它同时播放两个振荡器，没有问题，但是重复了代码。如果我尝试将冗余代码放入一个函数中，它将无法正常工作。

ctx = new AudioContext();
gain = ctx.createGain();
createAndPlayOsc(450);
createAndPlayOsc(500);


function createAndPlayOsc(freq){
    console.log("creating osc with freq " + freq);
    var osc = ctx.createOscillator();
    osc.connect(gain);
    osc.frequency.value = freq;
    osc.start();
    osc.stop(2);
    console.log("playing osc with freq " + freq);
}

即使我发送AudioContext

ctx = new AudioContext();
gain = ctx.createGain();
createAndPlayOsc(450, ctx);
createAndPlayOsc(500, ctx);


function createAndPlayOsc(freq, context){
    console.log("creating osc with freq " + freq);
    var osc = context.createOscillator();
    osc.connect(gain);
    osc.frequency.value = freq;
    osc.start();
    osc.stop(2);
    console.log("playing osc with freq " + freq);
}

或gainNode和context

ctx = new AudioContext();
gain = ctx.createGain();
createAndPlayOsc(450, ctx, gain);
createAndPlayOsc(500, ctx, gain);


function createAndPlayOsc(freq, context, gainNode){
    console.log("creating osc with freq " + freq);
    var osc = context.createOscillator();
    osc.connect(gainNode);
    osc.frequency.value = freq;
    osc.start();
    osc.stop(2);
    console.log("playing osc with freq " + freq);
}

我缺少什么？

最佳答案

您忘记了将增益连接到上下文：

gain.connect(ctx.destination);