stream-controller: dont backtrack if dropped frames on first frag

related to video-dev#1377
mes · Oct 5, 2017 · 8f0ba57 · 8f0ba57
1 parent 9255b96
commit 8f0ba57
Showing 1 changed file with 15 additions and 10 deletions.
diff --git a/src/controller/stream-controller.js b/src/controller/stream-controller.js
@@ -1136,16 +1136,21 @@ class StreamController extends EventHandler {
         frag.dropped = data.dropped;
         if (frag.dropped) {
           if (!frag.backtracked) {
-            logger.warn('missing video frame(s), backtracking fragment');
-            // Return back to the IDLE state without appending to buffer
-            // Causes findFragments to backtrack a segment and find the keyframe
-            // Audio fragments arriving before video sets the nextLoadPosition, causing _findFragments to skip the backtracked fragment
-            frag.backtracked = true;
-            this.nextLoadPosition = data.startPTS;
-            this.state = State.IDLE;
-            this.fragPrevious = frag;
-            this.tick();
-            return;
+            const levelDetails = level.details;
+            if (levelDetails && frag.sn === levelDetails.startSN) {
+              logger.warn('missing video frame(s) on first frag, appending with gap');
+            } else {
+              logger.warn('missing video frame(s), backtracking fragment');
+              // Return back to the IDLE state without appending to buffer
+              // Causes findFragments to backtrack a segment and find the keyframe
+              // Audio fragments arriving before video sets the nextLoadPosition, causing _findFragments to skip the backtracked fragment
+              frag.backtracked = true;
+              this.nextLoadPosition = data.startPTS;
+              this.state = State.IDLE;
+              this.fragPrevious = frag;
+              this.tick();
+              return;
+            }
           } else {
             logger.warn('Already backtracked on this fragment, appending with the gap');
           }