Forgot to commit change from last PR discussion (#2198)

* Forgot to commit change from last PR discussion

* fix test case

---------

Co-authored-by: cnderrauber <zengjie9004@gmail.com>

pkg/sfu/videolayerselector/dependencydescriptor.go

@@ -332,21 +332,10 @@ func (d *DependencyDescriptor) CheckSync() (locked bool, layer int32) {
 		return false, layer
 	}
 
-	allBroken := true
-	for _, chain := range d.chains {
-		if !chain.Broken() {
-			allBroken = false
-			break
-		}
-	}
-	if allBroken {
-		return false, layer
-	}
-
 	d.decodeTargetsLock.RLock()
 	defer d.decodeTargetsLock.RUnlock()
 	for _, dt := range d.decodeTargets {
-		if dt.Active() && dt.Layer.Spatial == layer && dt.Valid() {
+		if dt.Active() && dt.Layer.Spatial <= d.GetTarget().Spatial && dt.Valid() {
 			d.logger.Debugw(fmt.Sprintf("checking sync, matching decode target, layer: %d, dt: %s, dts: %+v", layer, dt, d.decodeTargets))
 			return true, layer
 		}

pkg/sfu/videolayerselector/dependencydescriptor_test.go

@@ -253,16 +253,11 @@ func TestDependencyDescriptor(t *testing.T) {
 	}
 	require.True(t, switchToLower)
 
-	// not sync with requested layer
+	// sync with requested layer
 	ddSelector.SetRequestSpatial(targetLayer.Spatial)
 	locked, layer := ddSelector.CheckSync()
-	require.False(t, locked)
-	require.Equal(t, targetLayer.Spatial, layer)
-
-	// request to current layer, sync
-	ddSelector.SetRequestSpatial(ddSelector.GetCurrent().Spatial)
-	locked, _ = ddSelector.CheckSync()
 	require.True(t, locked)
+	require.Equal(t, targetLayer.Spatial, layer)
 }
 
 func createDDFrames(maxLayer buffer.VideoLayer, startFrameNumber uint16) []*buffer.ExtPacket {