Question

我使用本教程：http://typedarray.org/from-microphone-to-wav-with-getusermedia-and-web-audio/

以及此实时演示页：http://typedarray.org/wp-content/projects/WebAudioRecorder/

创建我的高频分析仪。

我的问题是Web Audio API，我的东西，默认情况下会切断高频。

当我录制WAV并播放10000hz信号时，wav包含我的频率。

如果我播放17000hz信号，wav不包含我的频率。

如何禁用低通滤波器？

代码：

function success(e){
    // creates the audio context
    audioContext = window.AudioContext || window.webkitAudioContext;
    context = new audioContext();

    // creates a gain node
    volume = context.createGain();

    // creates an audio node from the microphone incoming stream
    audioInput = context.createMediaStreamSource(e);

    // connect the stream to the gain node
    audioInput.connect(volume);

    /* From the spec: This value controls how frequently the audioprocess event is 
    dispatched and how many sample-frames need to be processed each call. 
    Lower values for buffer size will result in a lower (better) latency. 
    Higher values will be necessary to avoid audio breakup and glitches */
    var bufferSize = 2048;
    recorder = context.createJavaScriptNode(bufferSize, 2, 2);

    recorder.onaudioprocess = function(e){
        console.log ('recording');
        var left = e.inputBuffer.getChannelData (0);
        var right = e.inputBuffer.getChannelData (1);
        // we clone the samples
        leftchannel.push (new Float32Array (left));
        rightchannel.push (new Float32Array (right));
        recordingLength += bufferSize;
    }

    // we connect the recorder
    volume.connect (recorder);
    recorder.connect (context.destination); 
}

Answer 1

这是getUserMedia而不是Web Audio API。默认情况下，MediaStream为您提供的getUserMedia包含已经存在的数据（取决于浏览器）： - 回声被取消了 - 噪音受到抑制 - 已应用自动增益补偿

您可以使用约束禁用它们（例如，对于Firefox）：

navigator.mediaDevices.getUserMedia({audio: { echoCancellation: false, mozNoiseSuppression: false, mozAutoGainControl: false });

我们目前正在对这些属性进行标准化，但我们还没有完成。

Web音频API - 捕获音频 - 禁用低通滤波器

1 个答案: