else/Javascript/audio_compare_test.html
2016-07-27 20:41:13 -07:00

210 lines
4.3 KiB
HTML

<!DOCTYPE html>
<html>
<!--
This page lets you compare multiple audio tracks simultaneously,
to see whether you can spot the difference in audio quality.
The audio elements are scrambled when loaded, you can hover over the
"spoiler" tag to see the file.
-->
<head>
<title>Fear your ears</title>
<meta charset="UTF-8">
</head>
<body>
<p>Drag files onto the page</p>
<button onclick="cycle();">Cycle</button>
<button onclick="pause_all();">Pause</button>
<button onclick="play_all();">Play</button>
<p>
Please use this slider as the seekbar. Dragging the audio elements directly causes syncing problems.
<br>
<input id="seekbar" type="range">
</p>
<div id="workspace">
</div>
</body>
</html>
<style>
html, body
{
height: 100%;
}
audio
{
vertical-align: middle;
width: 600px;
}
div button
{
height: 100%;
vertical-align: middle;
}
div
{
display: block;
}
input
{
width: 600px;
}
#workspace
{
width: 100%;
height: 100%;
}
</style>
<script type="text/javascript">
var WORKSPACE = document.getElementById("workspace");
var SEEKBAR = document.getElementById("seekbar");
var audios = [];
var current = 0;
var duration = 0;
var seek_lock = false;
SEEKBAR.min = 0;
SEEKBAR.max = 0;
SEEKBAR.value = 0;
function cycle()
{
if (audios == undefined)
{
return
}
if (audios.length == 0)
{
return;
}
current = (current + 1) % audios.length;
switch_to(current)
}
function drop_event(e)
{
e = e || window.event;
e.preventDefault();
var files = Array.from(e.dataTransfer.files);
shuffle(files);
while (WORKSPACE.lastChild)
{
WORKSPACE.removeChild(WORKSPACE.lastChild);
}
for (var index = 0; index < files.length; index += 1)
{
var mediadiv = document.createElement("div");
var anchor = document.createElement("a");
var audio = document.createElement("audio");
var source = document.createElement("source");
var choosebutton = document.createElement("button");
audio.preload = true;
audio.controls = true;
audio.volume = 0
anchor.innerHTML = "spoiler";
anchor.title = files[index]["name"];
anchor.href = "#";
source.src = URL.createObjectURL(files[index]);
choosebutton.innerHTML = "play";
choosebutton.index = index;
choosebutton.onclick = function()
{
current = this.index;
switch_to(current);
}
audio.appendChild(source);
mediadiv.appendChild(anchor);
mediadiv.appendChild(audio);
mediadiv.appendChild(choosebutton);
WORKSPACE.appendChild(mediadiv);
audios.push(audio);
}
load();
}
function load()
{
audios = Array.from(document.getElementsByTagName("audio"));
current = -1;
if (audios.length == 0)
{
return;
}
audios[0].oncanplay = function()
{
duration = this.duration;
SEEKBAR.max = duration;
}
SEEKBAR.value = 0;
}
function pause_all()
{
for (var index = 0; index < audios.length; index += 1)
{
audios[index].pause();
}
}
function play_all()
{
for (var index = 0; index < audios.length; index += 1)
{
audios[index].play();
}
}
function seek_event()
{
if (seek_lock)
{
console.log("locked");
return;
}
pause_all();
seek_lock = true;
var timestamp = this.value;
for (var index = 0; index < audios.length; index += 1)
{
audios[index].currentTime = timestamp;
}
setTimeout(function(){seek_lock = false; play_all();}, 500);
}
function shuffle(a)
{
var target_index;
var temp;
for (var index = a.length; index > 0; index -= 1)
{
target_index = Math.floor(Math.random() * index);
temp = a[index - 1];
a[index - 1] = a[target_index];
a[target_index] = temp;
}
}
function switch_to(audio_index)
{
play_all();
for (var index = 0; index < audios.length; index += 1)
{
audios[index].volume = 0;
}
audios[audio_index].volume = 1;
}
SEEKBAR.onchange = seek_event;
document.body.addEventListener('drop', drop_event);
document.body.addEventListener('dragover', function(e){e.preventDefault();});
</script>