Fix some ie bug

packages/artplayer/src/subtitle.js

@@ -111,6 +111,7 @@ export default class Subtitle extends Component {
         return fetch(url)
             .then((response) => response.arrayBuffer())
             .then((buffer) => {
+                if (!window.TextDecoder) return;
                 const decoder = new TextDecoder(opt.encoding || subtitle.encoding);
                 const text = decoder.decode(buffer);