i've not really tested it much but you can try this. in the editor, replace
function on_metadb_changed() {
a.metadb_changed();
}
with
function on_metadb_changed() {
if (!p.metadb) return;
if (a.id != 0) return a.metadb_changed();
var embed_img = utils.GetAlbumArtEmbedded(p.metadb.RawPath, 0);
if (!embed_img) return a.metadb_changed();
a.img && a.img.Dispose();
a.path = "";
var folder = tf("$directory_path(%path%)\\", p.metadb);
var big_img = embed_img;
var big_path = p.metadb.Path;
var images = [];
images = images.concat(utils.Glob(folder + "folder.*").toArray(), utils.Glob(folder + "cover.*").toArray());
for (var i in images) {
var temp_img = gdi.Image(images[i]);
if (temp_img.Width > big_img.Width && temp_img.Height > big_img.Height) {
big_img = temp_img;
big_path = images[i];
}
}
a.img = big_img;
a.path = big_path;
window.RepaintRect(a.x, a.y, a.w, a.h);
}
edited to fix small typo.