stream-controller: don't switch to ENDED state in case fragPrevious i…

…s last playlist frag but currentTime is not buffered, or if stream not buffered till the end

also don't allow seeking more than maxSeekHole on loadedmetadata

related to #1193
related to #1119

src/controller/stream-controller.js

@@ -241,9 +241,11 @@ class StreamController extends EventHandler {
       return;
     }
 
-    // we just got done loading the final fragment, check if we need to finalize media stream
+    // we just got done loading the final fragment, and currentPos is buffered, and there is no other buffered range after ...
+    // rationale is that in case there are any buffered rangesafter, it means that there are unbuffered portion in between
+    // so we should not switch to ENDED in that case, to be able to buffer themx
     let fragPrevious = this.fragPrevious;
-    if (!levelDetails.live && fragPrevious && fragPrevious.sn === levelDetails.endSN) {
+    if (!levelDetails.live && fragPrevious && fragPrevious.sn === levelDetails.endSN && bufferLen && !bufferInfo.nextStart) {
         // fragPrevious is last fragment. retrieve level duration using last frag start offset + duration
         // real duration might be lower than initial duration if there are drifts between real frag duration and playlist signaling
         const duration = Math.min(media.duration,fragPrevious.start + fragPrevious.duration);
@@ -252,14 +254,14 @@ class StreamController extends EventHandler {
         // tolerate up to one frag duration to cope with these cases.
         // also cope with almost zero last frag duration (max last frag duration with 200ms) refer to https://github.com/video-dev/hls.js/pull/657
         if (duration - Math.max(bufferInfo.end,fragPrevious.start) <= Math.max(0.2,fragPrevious.duration)) {
-        // Finalize the media stream
-        let data = {};
-        if (this.altAudio) {
-          data.type = 'video';
-        }
-        this.hls.trigger(Event.BUFFER_EOS,data);
-        this.state = State.ENDED;
-        return;
+          // Finalize the media stream
+          let data = {};
+          if (this.altAudio) {
+            data.type = 'video';
+          }
+          this.hls.trigger(Event.BUFFER_EOS,data);
+          this.state = State.ENDED;
+          return;
       }
     }
 
@@ -1387,7 +1389,8 @@ class StreamController extends EventHandler {
   }
 
 _checkBuffer() {
-    var media = this.media;
+    var media = this.media,
+        config = this.config;
     // if ready state different from HAVE_NOTHING (numeric value 0), we are allowed to seek
     if(media && media.readyState) {
         let currentTime = media.currentTime,
@@ -1399,13 +1402,15 @@ _checkBuffer() {
         // only adjust currentTime if different from startPosition or if startPosition not buffered
         // at that stage, there should be only one buffered range, as we reach that code after first fragment has been buffered
         let startPosition = media.seeking ? currentTime : this.startPosition,
-            startPositionBuffered = BufferHelper.isBuffered(mediaBuffer,startPosition);
+            startPositionBuffered = BufferHelper.isBuffered(mediaBuffer,startPosition),
+            firstbufferedPosition = buffered.start(0);
         // if currentTime not matching with expected startPosition or startPosition not buffered
-        if (currentTime !== startPosition || !startPositionBuffered) {
+        if (currentTime !== startPosition ||
+          (!startPositionBuffered && (Math.abs(startPosition-firstbufferedPosition) < config.maxSeekHole))) {
           logger.log(`target start position:${startPosition}`);
           // if startPosition not buffered, let's seek to buffered.start(0)
           if(!startPositionBuffered) {
-            startPosition = buffered.start(0);
+            startPosition = firstbufferedPosition;
             logger.log(`target start position not buffered, seek to buffered.start(0) ${startPosition}`);
           }
           logger.log(`adjust currentTime from ${currentTime} to ${startPosition}`);
@@ -1419,8 +1424,7 @@ _checkBuffer() {
                                 media.ended  || // not playing when media is ended
                                 media.buffered.length === 0), // not playing if nothing buffered
             jumpThreshold = 0.5, // tolerance needed as some browsers stalls playback before reaching buffered range end
-            playheadMoving = currentTime !== this.lastCurrentTime,
-            config = this.config;
+            playheadMoving = currentTime !== this.lastCurrentTime;
 
         if (playheadMoving) {
           // played moving, but was previously stalled => now not stuck anymore