GUI, but still shit a bit

internal/source/source.go

@@ -403,6 +403,7 @@ func (s *SyncSource) Close() error {
 
 // NextSync reads both at a synced timestamp. Returns video Frame + audio AudioFrame
 func (s *SyncSource) NextSync(ctx context.Context, audioBatch uint64, timeout time.Duration) (Frame, AudioFrame, error) {
+	var timeouts int
 	for {
 		select {
 		case <-ctx.Done():
@@ -421,7 +422,19 @@ func (s *SyncSource) NextSync(ctx context.Context, audioBatch uint64, timeout ti
 					s.idx = mxl.CurrentIndex(s.rate)
 					continue
 				}
-				return Frame{}, AudioFrame{}, fmt.Errorf("GetGraing: %w", gerr)
+				if errors.Is(gerr, mxl.ErrOutOfRangeLate) {
+					s.idx = mxl.CurrentIndex(s.rate)
+					continue
+				}
+				if errors.Is(gerr, mxl.ErrOutOfRangeEarly) {
+					select {
+					case <-time.After(5 * time.Millisecond):
+					case <-ctx.Done():
+						return Frame{}, AudioFrame{}, ctx.Err()
+					}
+					continue
+				}
+				return Frame{}, AudioFrame{}, fmt.Errorf("GetGrain: %w", gerr)
 			}
 			// read audio at the same timestamp
 			aIdx := mxl.TimestampToIndex(s.aRate, ts)
@@ -451,14 +464,19 @@ func (s *SyncSource) NextSync(ctx context.Context, audioBatch uint64, timeout ti
 			}
 			// even if audio failed, video returns
 			return vFrame, aFrame, nil
-		case errors.Is(err, mxl.ErrTimeout), errors.Is(err, mxl.ErrOutOfRangeEarly):
+		case errors.Is(err, mxl.ErrTimeout), errors.Is(err, mxl.ErrOutOfRangeEarly), errors.Is(err, mxl.ErrOutOfRangeLate):
+			timeouts++
+			if timeouts > 10 {
+				timeouts = 0
+				s.idx = mxl.CurrentIndex(s.rate)
+				return Frame{}, AudioFrame{}, fmt.Errorf("sync: feeds not responding")
+			}
+			s.idx = mxl.CurrentIndex(s.rate)
 			select {
 			case <-time.After(5 * time.Millisecond):
 			case <-ctx.Done():
 				return Frame{}, AudioFrame{}, ctx.Err()
 			}
-		case errors.Is(err, mxl.ErrOutOfRangeLate):
-			s.idx = mxl.CurrentIndex(s.rate)
 		default:
 			return Frame{}, AudioFrame{}, fmt.Errorf("WaitForDataAt: %w", err)
 		}