16

我正在使用以下方法播放包含 wav 数据的字节数组。正在从 GWT 项目调用该函数。

此功能播放声音，但听起来像是某种地狱般的怪物。采样率绝对正确（声音是由 neospeech 生成的），我尝试了 numberOfSamples 的各种值，这似乎代表了音频数据的长度。

numberOfSamples 的值大于 30000 将播放音频文件的完整长度，但会出现乱码和可怕的问题。

那么，我做错了什么？

function playByteArray(byteArray, numberOfSamples) {
    sampleRate = 8000;

    if (!window.AudioContext) {
        if (!window.webkitAudioContext) {
            alert("Your browser does not support any AudioContext and cannot play back this audio.");
            return;
        }
        window.AudioContext = window.webkitAudioContext;
    }

    var audioContext = new AudioContext();

    var buffer = audioContext.createBuffer(1, numberOfSamples, sampleRate);
    var buf = buffer.getChannelData(0);
    for (i = 0; i < byteArray.length; ++i) {
        buf[i] = byteArray[i];
    }

    var source = audioContext.createBufferSource();
    source.buffer = buffer;
    source.connect(audioContext.destination);
    source.start(0);
}
4

3 回答 3

27

我想出了如何做我在问题中描述的事情，并认为我应该发布它以造福他人。代码如下。我调用 playByteArray 并将其传递给包含 pcm wav 数据的字节数组。 

window.onload = init;
var context;    // Audio context
var buf;        // Audio buffer

function init() {
if (!window.AudioContext) {
    if (!window.webkitAudioContext) {
        alert("Your browser does not support any AudioContext and cannot play back this audio.");
        return;
    }
        window.AudioContext = window.webkitAudioContext;
    }

    context = new AudioContext();
}

function playByteArray(byteArray) {

    var arrayBuffer = new ArrayBuffer(byteArray.length);
    var bufferView = new Uint8Array(arrayBuffer);
    for (i = 0; i < byteArray.length; i++) {
      bufferView[i] = byteArray[i];
    }

    context.decodeAudioData(arrayBuffer, function(buffer) {
        buf = buffer;
        play();
    });
}

// Play the loaded file
function play() {
    // Create a source node from the buffer
    var source = context.createBufferSource();
    source.buffer = buf;
    // Connect to the final output node (the speakers)
    source.connect(context.destination);
    // Play immediately
    source.start(0);
}
于 2014-06-12T21:30:29.313 回答
6

清理建议：

function playByteArray( bytes ) {
    var buffer = new Uint8Array( bytes.length );
    buffer.set( new Uint8Array(bytes), 0 );

    context.decodeAudioData(buffer.buffer, play);
}

function play( audioBuffer ) {
    var source = context.createBufferSource();
    source.buffer = audioBuffer;
    source.connect( context.destination );
    source.start(0);
}
于 2014-07-29T16:05:33.023 回答
2

与 AudioContext 相比，这种方法适用于最新的 iOS Safari。音频对象应该在点击/点击（用户交互）事件时创建，所以不要在请求回调中这样做。

const audio = new Audio()    
fetch(url, options) // set content header to array buffer
      .then((response) => {
        var blob = new Blob([response.value], { type: 'audio/mp3' })
        var url = window.URL.createObjectURL(blob)        
        audio.src = url
        audio.play()
      })

从这里摘录

于 2019-07-20T22:47:04.860 回答