Cue removal and Error fixes

adding code to remvoe the cues after 5 mins for live and setting the state to idle for any error not just subtitle related.

src/controller/subtitle-stream-controller.js

@@ -100,11 +100,12 @@ export class SubtitleStreamController extends TaskLoop {
 
   // If something goes wrong, procede to next frag, if we were processing one.
   onError (data) {
-    let frag = data.frag;
-    // don't handle error not related to subtitle fragment
-    if (!frag || frag.type !== 'subtitle') {
-      return;
-    }
+    //Commenting out this code since we need to reset the state for any error
+    // let frag = data.frag;
+    // // don't handle error not related to subtitle fragment
+    // if (!frag || frag.type !== 'subtitle') {
+    //   return;
+    // }
     this.state = State.IDLE;
   }
 
@@ -221,7 +222,7 @@ export class SubtitleStreamController extends TaskLoop {
         this.state = State.KEY_LOADING;
         this.hls.trigger(Event.KEY_LOADING, { frag: foundFrag });
       } else if (foundFrag && this.fragmentTracker.getState(foundFrag) === FragmentState.NOT_LOADED) {
-        // only load if fragment is not loaded
+        // only load if fragment is not loaded        
         foundFrag.trackId = trackId; // Frags don't know their subtitle track ID, so let's just add that...
         this.fragCurrent = foundFrag;
         this.state = State.FRAG_LOADING;

src/controller/timeline-controller.js

@@ -271,7 +271,7 @@ class TimelineController extends EventHandler {
       hls = this.hls;
 
     // Parse the WebVTT file contents.
-    WebVTTParser.parse(payload, this.initPTS[frag.cc], vttCCs, frag.cc, function (cues) {
+    WebVTTParser.parse(payload, this.initPTS[frag.cc], vttCCs, frag.cc,(cues) =>  {
       const currentTrack = textTracks[frag.trackId];
       // WebVTTParser.parse is an async method and if the currently selected text track mode is set to "disabled"
       // before parsing is done then don't try to access currentTrack.cues.getCueById as cues will be null
@@ -280,8 +280,12 @@ class TimelineController extends EventHandler {
         hls.trigger(Event.SUBTITLE_FRAG_PROCESSED, { success: false, frag: frag });
         return;
       }     
+      let minStartTime = Number.MAX_SAFE_INTEGER;
       // Add cues and trigger event with success true.
+
       cues.forEach(cue => {
+        //find the first cue in the entire cue set since its not always sorted
+        minStartTime = Math.min(cue.startTime,minStartTime);
         // Sometimes there are cue overlaps on segmented vtts so the same
         // cue can appear more than once in different vtt files.
         // This avoid showing duplicated cues with same timecode and text.
@@ -294,8 +298,20 @@ class TimelineController extends EventHandler {
             currentTrack.addCue(textTrackCue);
           }
         }
-      }
+      }         
       );
+
+      let liveSyncPosition = hls.streamController.liveSyncPosition;
+      //need to remove cues only for live so if there is no sync position its a VOD
+      // if there is a better way to detect live vs vod we can use it. 
+      while (cues.length > 0 && liveSyncPosition !== undefined ){
+        //We remove cues which are more than 5 minutes old than the current cue
+        if (currentTrack.cues[0].startTime < minStartTime - 300){
+          currentTrack.removeCue(currentTrack.cues[0]);
+        } else {
+          break;
+        }
+      }
       hls.trigger(Event.SUBTITLE_FRAG_PROCESSED, { success: true, frag: frag });
     },
     function (e) {

src/utils/webvtt-parser.js

@@ -93,15 +93,12 @@ const WebVTTParser = {
       }
 
       if (presentationTime) {
-        // If we have MPEGTS, offset = presentation time + discontinuity offset
-
+        // If we have MPEGTS, offset = presentation time + discontinuity offset        
         cueOffset = presentationTime - vttCCs.presentationOffset;
-        console.log('cueOFFSET IS ' + presentationTime + ' vttCCs.presentationOffset ' + vttCCs.presentationOffset);
       }
      // console.log(cue.startTime + ' before');
       cue.startTime += cueOffset - localTime;
       cue.endTime += cueOffset - localTime;
-      console.log(cue.startTime);
       // Create a unique hash id for a cue based on start/end times and text.
       // This helps timeline-controller to avoid showing repeated captions.
       cue.id = hash(cue.startTime.toString()) + hash(cue.endTime.toString()) + hash(cue.text);