Javascript:UInt8Array到Float32Array

Question

我有一些8位PCM格式的音频缓冲区需要通过网络音频播放,只能接受签名的32位PCM.现在我有一些pcm_u8数据的ArrayBuffer(来自Uint8array).如何将其转换为Float32Array？

Answer 1

此函数将ArrayBuffer转换为Float32Array

var convertBlock(buffer) { // incoming data is an ArrayBuffer
    var incomingData = new Uint8Array(buffer); // create a uint8 view on the ArrayBuffer
    var i, l = incomingData.length; // length, we need this for the loop
    var outputData = new Float32Array(incomingData.length); // create the Float32Array for output
    for (i = 0; i < l; i++) {
        outputData[i] = (incomingData[i] - 128) / 128.0; // convert audio to float
    }
    return outputData; // return the Float32Array
}

这个将Uint8Array转换为Float32Array

var convertBlock(incomingData) { // incoming data is a UInt8Array
    var i, l = incomingData.length;
    var outputData = new Float32Array(incomingData.length);
    for (i = 0; i < l; i++) {
        outputData[i] = (incomingData[i] - 128) / 128.0;
    }
    return outputData;
}

Answer 2

ECMAScript 2015及以后版本TypedArray.from将任何类型化数组(实际上是任何可迭代数组)转换为指定的类型化数组格式.

因此,将Uint8Array转换为Float32Array现在就像以下一样简单:

const intArray = new Uint8Array()
const floatArray = Float32Array.from(intArray)