如何在javascript中捕获音频？

Question

我目前正在使用getUserMedia(),仅适用于Firefox和Chrome,但它已被弃用,仅适用于https(在Chrome中).有没有其他/更好的方法来获得适用于所有平台的javascript中的语音输入？

例如,像web.whatsapp.com app这样的网站如何录制音频？getUserMedia()提示第一次用户允许录音,而Whatsapp应用程序不需要用户的许可.

在getUserMedia()我目前正在使用这个样子的:

navigator.getUserMedia(
    {
        "audio": {
            "mandatory": {
                "googEchoCancellation": "false",
                "googAutoGainControl": "false",
                "googNoiseSuppression": "false",
                "googHighpassFilter": "false"
            },
            "optional": []
        },
    }, gotStream, function(e) {
        console.log(e);
    });

Answer 1

Chrome 60+确实需要使用https,因为它getUserMedia是一个强大的功能.API访问不应在非安全域中工作,因为该API访问可能会流失到非安全的actor.不过,Firefox仍支持getUserMediaover http.

我一直在使用RecorderJS,它很好地满足了我的目的.这是一个代码示例.(来源)

function RecordAudio(stream, cfg) {

  var config = cfg || {};
  var bufferLen = config.bufferLen || 4096;
  var numChannels = config.numChannels || 2;
  this.context = stream.context;
  var recordBuffers = [];
  var recording = false;
  this.node = (this.context.createScriptProcessor ||
    this.context.createJavaScriptNode).call(this.context,
    bufferLen, numChannels, numChannels);

  stream.connect(this.node);
  this.node.connect(this.context.destination);

  this.node.onaudioprocess = function(e) {
    if (!recording) return;
    for (var i = 0; i < numChannels; i++) {
      if (!recordBuffers[i]) recordBuffers[i] = [];
      recordBuffers[i].push.apply(recordBuffers[i], e.inputBuffer.getChannelData(i));
    }
  }

  this.getData = function() {
    var tmp = recordBuffers;
    recordBuffers = [];
    return tmp; // returns an array of array containing data from various channels
  };

  this.start() = function() {
    recording = true;
  };

  this.stop() = function() {
    recording = false;
  };
}

用法很简单:

var recorder = new RecordAudio(userMedia);
recorder.start();
recorder.stop();
var recordedData = recorder.getData()

编辑:如果没有任何效果,您可能还想检查此答案.

Answer 2

Recorder JS为您轻松完成工作.它适用于Web Audio API节点

Chrome和Firefox浏览器现已发展.有一个内置的MediaRecoderAPI,可以为您录音.

navigator.mediaDevices.getUserMedia({audio:true})
    .then(stream => {
        rec = new MediaRecorder(stream);
        rec.ondataavailable = e => {
            audioChunks.push(e.data);
            if (rec.state == "inactive"){
               // Use blob to create a new Object URL and playback/download
            }
        }
    })
    .catch(e=>console.log(e));

工作演示

MediaRecoder 支持从

Chrome支持:47

Firefox支持:25.0