Files
squoosh/codecs/webp_dec/example.html
2018-06-14 13:32:05 +01:00

46 lines
1.8 KiB
HTML

<!doctype html>
<script src='webp_dec.js'></script>
<script>
const Module = webp_dec();
async function loadFile(src) {
const resp = await fetch(src);
return await resp.arrayBuffer();
}
Module.onRuntimeInitialized = async _ => {
const api = {
version: Module.cwrap('version', 'number', []),
create_buffer: Module.cwrap('create_buffer', 'number', ['number', 'number']),
destroy_buffer: Module.cwrap('destroy_buffer', '', ['number']),
decode: Module.cwrap('decode', '', ['number', 'number']),
free_result: Module.cwrap('free_result', '', ['number']),
get_result_pointer: Module.cwrap('get_result_pointer', 'number', []),
get_result_width: Module.cwrap('get_result_width', 'number', []),
get_result_height: Module.cwrap('get_result_height', 'number', []),
};
console.log('Version:', api.version().toString(16));
const image = await loadFile('../example.webp');
const p = api.create_buffer(image.byteLength);
Module.HEAP8.set(new Uint8Array(image), p);
api.decode(p, image.byteLength);
const resultPointer = api.get_result_pointer();
if(resultPointer === 0) {
throw new Error("Could not decode image");
}
const resultWidth = api.get_result_width();
const resultHeight = api.get_result_height();
const resultView = new Uint8Array(Module.HEAP8.buffer, resultPointer, resultWidth * resultHeight * 4);
const result = new Uint8ClampedArray(resultView);
const imageData = new ImageData(result, resultWidth, resultHeight);
api.free_result(resultPointer);
api.destroy_buffer(p);
const canvas = document.createElement('canvas');
canvas.width = resultWidth;
canvas.height = resultHeight;
document.body.appendChild(canvas);
const ctx = canvas.getContext('2d');
ctx.putImageData(imageData, 0, 0);
};
</script>