Add progress

src/utils/extractProgress.js

@@ -0,0 +1,19 @@
+let duration = 0;
+
+const ts2sec = (ts) => {
+  const [h, m, s] = ts.split(':');
+  return (parseFloat(h) * 60 * 60) + (parseFloat(m) * 60) + parseFloat(s);
+};
+
+module.exports = ({ message }, progress) => {
+  if (message.startsWith('  Duration')) {
+    const ts = message.split(', ')[0].split(': ')[1];
+    duration = ts2sec(ts);
+  } else if (message.startsWith('frame')) {
+    const ts = message.split('time=')[1].split(' ')[0];
+    const t = ts2sec(ts);
+    progress({ ratio: t / duration });
+  } else if (message.startsWith('video:')) {
+    progress({ ratio: 1 });
+  }
+};