uupaa.aac.js/test/assets/a.html

AAC-LC/HE-AAC parser.

<script src="../../lib/WebModule.js"></script>
<script src="../../lib/AAC.js"></script>
<script src="../../lib/ADTS.js"></script>
<script>
var xhr = new XMLHttpRequest();
xhr.responseType = "arraybuffer";
xhr.onload = function() {
    var AudioContext = window.AudioContext || window.webkitAudioContext;
    var audioContext = new AudioContext();

    var aac  = new Uint8Array(xhr.response);
    var adts = WebModule.ADTS.parse(aac);
    var blob = WebModule.ADTS.toBlob(aac, adts);

    alert("adts duration:" + adts.duration);
    // Mac Chrome 51: 5.061950113378685
    // Mac Safari  9: 5.061950113378685

    var reader = new FileReader();

    reader.onload = function() {
        var arrayBuffer = reader.result;

        audioContext.decodeAudioData(arrayBuffer, function(audioBuffer) {
            alert("audioBuffer duration: " + audioBuffer.duration);
            // Mac Chrome 51: 7.238639455782313
            // Mac Safari  9: 5.061950206756592

            var currentTime = audioContext.currentTime;

            var sourceNode = audioContext.createBufferSource();

            sourceNode.buffer = audioBuffer; // set PCM Data
            sourceNode.connect(audioContext.destination);
            sourceNode.start(0, 0, adts.duration); // playback
            sourceNode.onended = function() {
              alert("elapsed time: " + (audioContext.currentTime - currentTime));
              // Mac Chrome 51: 5.073560090702948
              // Mac Safari  9: 5.061950113378685
            };
        });

    };
    reader.readAsArrayBuffer(blob);
};
xhr.open("GET", "./5s.aac");
xhr.send();
</script>