AudioContext.decodeAudioData（...）不能在iPhone上工作，但在其他地方工作

Question

我有以下非常基本的代码，它是更复杂问题的一部分。

我的问题是函数：context.decodeAudioData(arrayBuffer)不是在iPhone（在Safari和Chrome上试过）和Mac（Safari），但它适用于其他地方（Android和Windows 10（所有浏览器）。甚至它适用于Mac（Chrome）。

在Mac（Safari）上我收到以下错误：

Unhandled Promise Rejection: TypeError: Not enough arguments

这是代码：

window.AudioContext = window.AudioContext || window.webkitAudioContext;
const context = new AudioContext();
window.addEventListener('load', function() {
  const button_option_1 = document.querySelector('.button_option_1');
  const button_option_1_play = document.querySelector('.button_option_1_play');
  button_option_1_play.disabled = true;
  button_option_1.addEventListener('click', async function() {
    log('', false);
    let buffer;
    button_option_1_play.disabled = true;
    button_option_1_play.onclick = () => playBuffer(buffer);
    let time_start = new Date().getTime();
    let b64 = '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';
    arrayBuffer = base64ToArrayBuffer(b64);
    time_start = new Date().getTime();
    let audioBuffer = await context.decodeAudioData(arrayBuffer);
    let duration = sprintf('%.2fs', (new Date().getTime() - time_start) / 1000);
    log(sprintf('P3. Delay: +%s for decoding.', duration));
    button_option_1_play.disabled = false;
    buffer = audioBuffer;
    button_option_1_play.click();
  });
});

function playBuffer(buffer, from, duration) {
  const source = context.createBufferSource(); // source: AudioBufferSourceNode
  source.buffer = buffer;
  source.connect(context.destination);
  source.start(context.currentTime, from, duration);
}

function log(text, append = true) {
  let log = document.querySelector('.log');
  if (!append)
    log.innerHTML = '';
  let entry = document.createElement('div');
  entry.innerHTML = text;
  log.appendChild(entry);
}

function base64ToArrayBuffer(base64) {
  var binary_string = window.atob(base64);
  var len = binary_string.length;
  var bytes = new Uint8Array(len);
  for (var i = 0; i < len; i++) {
    bytes[i] = binary_string.charCodeAt(i);
  }
  return bytes.buffer;
}

.log {
  display: inline-block;
  font-family: "Courier New", Courier, monospace;
  font-size: 13px;
  margin-top: 10px;
  padding: 4px;
  background-color: #d4e4ff;
}

.divider {
  border-top: 1px solid #ccc;
  margin: 10px 0;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/sprintf/1.1.1/sprintf.min.js"></script>
<button class="button_option_1">Option 1</button>
<button class="button_option_1_play">Play</button><br />
<div class="log">[empty]</div>

这是相应的CodePen.io：

https://codepen.io/anon/pen/rZgEoo

Answer 1

Safari不知道基于decodeAudioData的承诺。您将不得不使用回调。

context.decodeAudioData(arrayBuffer, (buffer) => { 
          resolve(buffer); 
 }, (e) => { reject(e); });

Answer 2

context在iOS上创建后在suspended州。它需要在用户交互中调用resume才能成为running