服务器将音频数据保存为base64数据字符串。移动Web客户端获取数据并播放音频。
但是在iOS和Android中的移动Chrome中发现了一个问题,即带有数据uri的音频无法播放(issue)。
为了使它工作,我想知道客户端是否有办法将数据字符串转换为音频文件(如.m4a)并将音频src链接到文件?
答案 0 :(得分:11)
使用网络音频api直接计算,在iOS和Android中的移动浏览器中具有最佳兼容性。
function base64ToArrayBuffer(base64) {
var binaryString = window.atob(base64);
var len = binaryString.length;
var bytes = new Uint8Array( len );
for (var i = 0; i < len; i++) {
bytes[i] = binaryString.charCodeAt(i);
}
return bytes.buffer;
}
var base64 = '<data string retrieved from server>';
var audioContext = new (window.AudioContext || window.webkitAudioContext)();
var source = audioContext.createBufferSource();
audioContext.decodeAudioData(base64ToArrayBuffer(base64), function(buffer) {
source.buffer = buffer;
source.connect(audioContext.destination);
source.start(0);
});
适用于iOS Safari,Chrome和Android默认浏览器以及Chrome。
答案 1 :(得分:6)
有一种方法可以做你想要的东西,它适用于桌面,但我不能保证它适用于移动设备。我们的想法是将dataURI转换为ArrayBuffer,从中构造一个Blob,然后用它创建一个ObjectURL,传递给audio元素。这是代码(我在Linux下的Chrome / Firefox中进行了测试并且它可以工作):
<script>
var base64audio = "data:audio/ogg;base64,gibberish";
function dataURItoBlob(dataURI)
{
// Split the input to get the mime-type and the data itself
dataURI = dataURI.split( ',' );
// First part contains data:audio/ogg;base64 from which we only need audio/ogg
var type = dataURI[ 0 ].split( ':' )[ 1 ].split( ';' )[ 0 ];
// Second part is the data itself and we decode it
var byteString = atob( dataURI[ 1 ] );
var byteStringLen = byteString.length;
// Create ArrayBuffer with the byte string and set the length to it
var ab = new ArrayBuffer( byteStringLen );
// Create a typed array out of the array buffer representing each character from as a 8-bit unsigned integer
var intArray = new Uint8Array( ab );
for ( var i = 0; i < byteStringLen; i++ )
{
intArray[ i ] = byteString.charCodeAt( i );
}
return new Blob( [ intArray ], {type: type} );
}
document.addEventListener( 'DOMContentLoaded', function()
{
// Construct an URL from the Blob. This URL will remain valid until user closes the tab or you revoke it
// Make sure at some point (when you don't need the audio anymore) to do URL.revokeObjectURL() with the constructed URL
var objectURL = URL.createObjectURL(dataURItoBlob(base64audio));
// Pass the URL to the audio element and load it
var audio = document.getElementById( 'test' );
audio.src = objectURL;
audio.load();
} );
</script>
...
<audio id="test" controls />
我希望有所帮助;)