Make conversion cancelable

dev/convert.html

@@ -18,6 +18,12 @@
 		const target = new Metamuxer.BufferTarget();
 		const outputFormat = new Metamuxer.Mp4OutputFormat()
 
+		const abortController = new AbortController();
+		const button = document.createElement('button');
+		button.textContent = 'Cancel';
+		button.onclick = () => abortController.abort();
+		document.body.append(button);
+
 		console.time()
 		const res = await Metamuxer.convert({
 			input: new Metamuxer.Input({
@@ -61,7 +67,8 @@
 			},
 			onProgress: (event) => {
 				progress.value = event.completion;
-			}
+			},
+			abortSignal: abortController.signal
 		});
 		console.timeEnd()
 		console.log(res)