js中pcm怎么转g711a编码？

Question

在vue项目里面通过navigator.mediaDevices.getUserMedia({ audio: true }).then((stream)采集到的音频，怎么转成G711A编码？网上找的都是java、C这些语言的，要么就是node写的客户端等等，没有看到关于纯js的

Answer 1

const audioContext = new AudioContext();
const source = audioContext.createMediaStreamSource(stream);
const buffer = await audioContext.decodeAudioData(await stream.getAudioTracks()[0].getBuffer());
const g711a = audioContext.createScriptProcessor(1024, 1, 1);
g711a.onaudioprocess = (event) => {
  const input = event.inputBuffer.getChannelData(0);
  const output = new Float32Array(input.length);
  for (let i = 0; i < input.length; i++) {
    const sample = input[i];
    if (sample < -1) {
      sample = -1;
    } else if (sample > 1) {
      sample = 1;
    }
    output[i] = sample * 255;
  }
  event.outputBuffer.copyToChannel(output, 0);
};
source.connect(g711a);
g711a.connect(audioContext.destination);

Web Audio
https://developer.mozilla.org/zh-CN/docs/Web/API/Web_Audio_AP...

不知道是否可以