Add option to watch caption track changes and update language options

src/js/captions.js

@@ -83,6 +83,11 @@ const captions = {
         // Set toggled state
         this.toggleCaptions(active);
 
+        // Watch changes to textTracks and update captions menu
+        if (this.config.captions.update) {
+            utils.on(this.media.textTracks, 'change', captions.update.bind(this));
+        }
+
         // Update available languages in list
         captions.update.call(this);
     },

src/js/defaults.js

@@ -116,6 +116,9 @@ const defaults = {
     captions: {
         active: false,
         language: (navigator.language || navigator.userLanguage).split('-')[0],
+        // Listen to new tracks added after Plyr is initialized.
+        // This is needed for streaming captions, but may result in unselectable options
+        update: false,
     },
 
     // Fullscreen settings