Fix tournament videos stuttering when changing scenes

osu.Game.Tournament/Components/TourneyVideo.cs

@@ -7,6 +7,7 @@
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Video;
+using osu.Framework.Timing;
 using osu.Game.Graphics;
 
 namespace osu.Game.Tournament.Components
@@ -15,6 +16,9 @@ public class TourneyVideo : CompositeDrawable
     {
         private readonly VideoSprite video;
 
+        private ManualClock manualClock;
+        private IFrameBasedClock sourceClock;
+
         public TourneyVideo(Stream stream)
         {
             if (stream == null)
@@ -41,5 +45,22 @@ public bool Loop
                     video.Loop = value;
             }
         }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            sourceClock = Clock;
+            Clock = new FramedClock(manualClock = new ManualClock());
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            // we want to avoid seeking as much as possible, because we care about performance, not sync.
+            // to avoid seeking completely, we only increment out local clock when in an updating state.
+            manualClock.CurrentTime += sourceClock.ElapsedFrameTime;
+        }
     }
 }