在JavaScript中对PCM音频缓冲区进行下采样

我正在尝试对从audioContext获取的采样率进行下采样.我相信它是在44100,我希望它是11025.我想我可以平均每3个样本,它以正确的速率播放,但是音高太高,好像我们都在氦气.

在11025样本中将float32Array从44100下采样到int16Array的正确方法是什么？

var cOntext= new Flash.audioContext();
var audioInput = context.createMediaStreamSource(stream);
var recorder = context.createScriptProcessor(null, 1, 1);
recorder.Onaudioprocess= onAudio;
audioInput.connect(recorder);
recorder.connect(context.destination);

var OnAudio= function (e) {
    var left = e.inputBuffer.getChannelData(0);
    bStream.write(Flash.convertFloat32ToInt16(left));
}

var convertFloat32ToInt16 = function(buffer) {
    var l = buffer.length;
    var point = Math.floor(l/3);
    var buf = new Int16Array(point);
    for (var x = l; x > 0;) {
        var average = (buffer[x] + buffer[x-1] +  buffer[x-2]) / 3;
        buf[point] = average*0x7FFF;
        point -= 1;
        x -= 3;
    }
    return buf.buffer;
}

Neablis.. 15

对于任何需要答案的人.

var downsampleBuffer = function (buffer, sampleRate, outSampleRate) {
    if (outSampleRate == sampleRate) {
        return buffer;
    }
    if (outSampleRate > sampleRate) {
        throw "downsampling rate show be smaller than original sample rate";
    }
    var sampleRateRatio = sampleRate / outSampleRate;
    var newLength = Math.round(buffer.length / sampleRateRatio);
    var result = new Int16Array(newLength);
    var offsetResult = 0;
    var offsetBuffer = 0;
    while (offsetResult 

这将返回小于传递给它的采样率,同时还将其转换为int16Array而不是float32. 


1> Neablis..：
对于任何需要答案的人. 

var downsampleBuffer = function (buffer, sampleRate, outSampleRate) {
    if (outSampleRate == sampleRate) {
        return buffer;
    }
    if (outSampleRate > sampleRate) {
        throw "downsampling rate show be smaller than original sample rate";
    }
    var sampleRateRatio = sampleRate / outSampleRate;
    var newLength = Math.round(buffer.length / sampleRateRatio);
    var result = new Int16Array(newLength);
    var offsetResult = 0;
    var offsetBuffer = 0;
    while (offsetResult 

这将返回小于传递给它的采样率,同时还将其转换为int16Array而不是float32.