使用Web Audio Api AudioWorklet从音频流中抓取比特并进行BPM检测

Question

我正在尝试按照cwilso在下面的链接中建议的那样使用AudioWorklet获得块：Using web audio api for analyzing input from microphone (convert MediaStreamSource to BufferSource)，但不幸的是我没有让它运行。有人知道如何使用AudioWorker从流中获取数据块，以便进行分析吗？以下是我的代码：

navigator.mediaDevices.getUserMedia({ audio: true, video: false })
.then(function(stream) {
    /* use the stream */
    var audioCtx = new (window.AudioContext || window.webkitAudioContext)(); // define audio context
    var source = audioCtx.createMediaStreamSource(stream);
    //connect stream to a web audio context with a MediaStreamAudioNode
    source.connect(audioCtx);
    //Use an AudioWorklet to grab the bits and do detection
    //https://developers.google.com/web/updates/2017/12/audio-worklet
    //https://developers.google.com/web/updates/2018/06/audio-worklet-design-pattern
    //https://webaudio.github.io/web-audio-api/#audioworklet
    audioCtx.audioWorklet.addModule('AudioWorklet.js').then(() => {
      let bypassNode = new AudioWorkletNode(audioCtx, 'bypass-processor');
    });

    //collect chunks for beat detection

    //do BPM detection

})
.catch(function(err) {
    /* handle the error */
    alert("Error");
});
        // Script in an extra file like it is explained in the api
class BypassProcessor extends AudioWorkletProcessor {
process (inputs, outputs) {
// Single input, single channel.
let input = inputs[0];
let output = outputs[0];
output[0].set(input[0]);
// Process only while there are inputs.
alert(input);
alert(output);
return false;}}); registerProcessor('bypass-processor', BypassProcessor);

Answer 1

根据您需要进行多少处理，您可以在AudioWorkletNode本身中进行处理。

如果不是，则需要使用MessagePort将数据从AudioWorkletNode传递到主线程

您可能还会对MessagePort with AudioWorklet和AudioWorklet with SharedArrayBuffer and Worker感兴趣