52 lines
1.3 KiB
JavaScript
52 lines
1.3 KiB
JavaScript
|
import * as mpd from "./mpd.js";
|
||
|
|
import * as parser from "./parser.js";
|
||
|
|
|
||
|
|
let cache = {};
|
||
|
|
const SIZE = 64;
|
||
|
|
|
||
|
|
async function getImageData(songUrl) {
|
||
|
|
let data = [];
|
||
|
|
let offset = 0;
|
||
|
|
while (1) {
|
||
|
|
let params = ["albumart", `"${mpd.escape(songUrl)}"`, offset];
|
||
|
|
let lines = await mpd.command(params.join(" "));
|
||
|
|
if (lines.length == 1) { return null; }
|
||
|
|
|
||
|
|
data = data.concat(lines[2]);
|
||
|
|
let metadata = parser.linesToStruct(lines.slice(0, 2));
|
||
|
|
if (data.length >= Number(metadata["size"])) { return data; }
|
||
|
|
offset += Number(metadata["binary"]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
async function bytesToImage(bytes) {
|
||
|
|
let blob = new Blob([bytes]);
|
||
|
|
let image = document.createElement("img");
|
||
|
|
image.src = URL.createObjectURL(blob);
|
||
|
|
return new Promise(resolve => {
|
||
|
|
image.onload = () => resolve(image);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
async function resize(image) {
|
||
|
|
let canvas = document.createElement("canvas");
|
||
|
|
canvas.width = SIZE;
|
||
|
|
canvas.height = SIZE;
|
||
|
|
let ctx = canvas.getContext("2d");
|
||
|
|
ctx.drawImage(image, 0, 0, SIZE, SIZE);
|
||
|
|
|
||
|
|
return new Promise(resolve => canvas.toBlob(resolve));
|
||
|
|
}
|
||
|
|
|
||
|
|
export async function get(songUrl) {
|
||
|
|
if (songUrl in cache) { return cache[songUrl]; }
|
||
|
|
|
||
|
|
let data = await getImageData(songUrl);
|
||
|
|
let bytes = new Uint8Array(data);
|
||
|
|
let image = await bytesToImage(bytes);
|
||
|
|
let blob = await resize(image);
|
||
|
|
let url = URL.createObjectURL(blob);
|
||
|
|
cache[songUrl] = url;
|
||
|
|
return url;
|
||
|
|
}
|