Question

我使用this示例从设备麦克风捕获数据，但是我不知道如何将其转换为WAV文件以发送到服务器。

<script>
  var handleSuccess = function(stream) {
    var context = new AudioContext();
    var source = context.createMediaStreamSource(stream);
    var processor = context.createScriptProcessor(1024, 1, 1);

    source.connect(processor);
    processor.connect(context.destination);

    processor.onaudioprocess = function(e) {
      // Convert this to WAV and send to server
      console.log(e.inputBuffer);
    };
  };

  navigator.mediaDevices.getUserMedia({ audio: true, video: false })
      .then(handleSuccess);
</script>

Answer 1

^{披露 synth-js是我写的。}

以下脚本将以Blob的形式创建有效的WAV文件，其中包含音频的前5秒：

<script src="https://unpkg.com/synth-js/dst/synth.min.js"></script>
<script>
  var handleSuccess = function(stream) {
    var context = new AudioContext();
    var source = context.createMediaStreamSource(stream);
    var processor = context.createScriptProcessor(1024, 1, 1);
    var data = [];

    source.connect(processor);
    processor.connect(context.destination);

    processor.onaudioprocess = function(e) {
      data.push.apply(data, e.inputBuffer.getChannelData(0));
      // cut off after 5 seconds
      if (data.length >= context.sampleRate * 5) {
        context.close();
        var track = stream.getAudioTracks()[0];
        track.stop();
        // Convert this to WAV
        var wav = new synth.WAV(1, context.sampleRate, 16, true, data);
        var blob = wav.toBlob();
        // do something with blob
        var src = URL.createObjectURL(blob);
        var audio = new Audio();
        audio.controls = true;
        document.body.appendChild(audio);
        // play back audio
        audio.addEventListener('canplaythrough', function() { audio.play(); });
        audio.src = src;
      }
    };
  };

  navigator.mediaDevices.getUserMedia({ audio: true, video: false }).then(handleSuccess);
</script>

您可以在JSFiddle上尝试此操作，因为堆栈片段不允许访问麦克风。

第var wav = new synth.WAV(1, context.sampleRate, 16, true, data);行创建了一个新的WAV对象，该对象具有1个通道，采样率与输入匹配，WAV二进制文件中每个样本16位，采用小端格式（必需），并通过onaudioprocess事件。

从原始数据制作WAV文件

1 个答案: