2017-03-20 14:03:57 +01:00
|
|
|
<!DOCTYPE html>
|
|
|
|
|
<html lang="en">
|
|
|
|
|
|
|
|
|
|
<head>
|
|
|
|
|
<meta charset="UTF-8">
|
|
|
|
|
<title>simple Javascript WebP decoding demo, using Web-Assembly (WASM)</title>
|
|
|
|
|
<script type="text/javascript">
|
|
|
|
|
var Module = {
|
|
|
|
|
noInitialRun : true
|
|
|
|
|
};
|
|
|
|
|
</script>
|
|
|
|
|
<script type="text/javascript">
|
|
|
|
|
|
2017-07-31 21:45:07 +02:00
|
|
|
'use strict';
|
|
|
|
|
|
|
|
|
|
// main wrapper for the function decoding a WebP into a canvas object
|
|
|
|
|
var WebpToCanvas;
|
|
|
|
|
|
2017-03-20 14:03:57 +01:00
|
|
|
function init() {
|
|
|
|
|
var xhr = new XMLHttpRequest();
|
|
|
|
|
xhr.open('GET', 'webp_wasm.wasm', true);
|
|
|
|
|
xhr.responseType = 'arraybuffer';
|
|
|
|
|
xhr.onload = function() {
|
|
|
|
|
Module.wasmBinary = xhr.response;
|
|
|
|
|
var script = document.createElement('script');
|
|
|
|
|
script.src = "webp_wasm.js";
|
|
|
|
|
document.body.appendChild(script);
|
|
|
|
|
};
|
|
|
|
|
xhr.send(null);
|
|
|
|
|
}
|
2017-07-31 21:45:07 +02:00
|
|
|
window.onload = init;
|
2017-03-20 14:03:57 +01:00
|
|
|
|
|
|
|
|
function decode(webp_data, canvas_id) {
|
|
|
|
|
var result;
|
|
|
|
|
if (Module["asm"] != undefined) {
|
|
|
|
|
// wrapper for the function decoding a WebP into a canvas object
|
|
|
|
|
WebpToCanvas = Module.cwrap('WebpToSDL', 'number', ['array', 'number']);
|
|
|
|
|
// get the canvas to decode into
|
|
|
|
|
var canvas = document.getElementById(canvas_id);
|
|
|
|
|
if (canvas == null) return;
|
|
|
|
|
// clear previous picture (if any)
|
|
|
|
|
Module.canvas = canvas;
|
|
|
|
|
canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height);
|
|
|
|
|
// decode and measure timing
|
2017-07-31 21:45:07 +02:00
|
|
|
var start = new Date();
|
2017-03-20 14:03:57 +01:00
|
|
|
var ret = WebpToCanvas(webp_data, webp_data.length);
|
2017-07-31 21:45:07 +02:00
|
|
|
var end = new Date();
|
2017-03-20 14:03:57 +01:00
|
|
|
var decode_time = end - start;
|
|
|
|
|
result = 'decoding time: ' + decode_time +' ms.';
|
|
|
|
|
} else {
|
|
|
|
|
result = "WASM module not finished loading! Please retry";
|
|
|
|
|
}
|
|
|
|
|
// display timing result
|
2017-07-31 21:45:07 +02:00
|
|
|
var speed_result = document.getElementById('timing');
|
2017-03-20 14:03:57 +01:00
|
|
|
if (speed_result != null) {
|
|
|
|
|
speed_result.innerHTML = '<p>'+ result + '</p>';
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
function loadfile(filename, canvas_id) {
|
|
|
|
|
var xhr = new XMLHttpRequest();
|
|
|
|
|
xhr.open('GET', filename);
|
|
|
|
|
xhr.responseType = 'arraybuffer';
|
|
|
|
|
xhr.onreadystatechange = function() {
|
|
|
|
|
if (xhr.readyState == 4 && xhr.status == 200) {
|
|
|
|
|
var webp_data = new Uint8Array(xhr.response);
|
|
|
|
|
decode(webp_data, canvas_id);
|
|
|
|
|
}
|
|
|
|
|
};
|
|
|
|
|
xhr.send();
|
|
|
|
|
}
|
|
|
|
|
</script>
|
|
|
|
|
</head>
|
|
|
|
|
|
2017-07-31 21:45:07 +02:00
|
|
|
<body>
|
2017-03-20 14:03:57 +01:00
|
|
|
<p>
|
|
|
|
|
<strong>WebP demo using Web-Assembly</strong> -
|
|
|
|
|
</p>
|
|
|
|
|
<p>
|
|
|
|
|
WASM version of the WebP decoder, using libwebp compiled with
|
|
|
|
|
<a href="https://github.com/kripken/emscripten/wiki">Emscripten</a>.
|
|
|
|
|
</p>
|
|
|
|
|
<p id="image_buttons">
|
|
|
|
|
<input type="button" value="test image!"
|
|
|
|
|
onclick="loadfile('./test_webp_wasm.webp', 'output_canvas')">
|
|
|
|
|
</p>
|
|
|
|
|
<p id="timing">Timing: N/A</p>
|
|
|
|
|
<canvas id="output_canvas">Your browser does not support canvas</canvas>
|
|
|
|
|
</body>
|
|
|
|
|
</html>
|
