2 files changed, 48 insertions, 2 deletions

diff --git a/video/out/cocoa-cb/video_layer.swift b/video/out/cocoa-cb/video_layer.swift
index 2cea79bf3a..8e2eee621b 100644
--- a/video/out/cocoa-cb/video_layer.swift
+++ b/video/out/cocoa-cb/video_layer.swift
@@ -31,6 +31,11 @@ class VideoLayer: CAOpenGLLayer {
     var neededFlips: Int = 0
     var cglContext: CGLContextObj? = nil
 
+    enum Draw: Int { case normal = 1, atomic, atomicEnd }
+    var draw: Draw = .normal
+    let drawLock = NSLock()
+    var surfaceSize: NSSize?
+
     var canDrawOffScreen: Bool = false
     var lastThread: Thread? = nil
 
@@ -42,8 +47,6 @@ class VideoLayer: CAOpenGLLayer {
         }
     }
 
-    var surfaceSize: NSSize?
-
     var inLiveResize: Bool = false {
         didSet {
             if inLiveResize == false {
@@ -97,9 +100,23 @@ class VideoLayer: CAOpenGLLayer {
     }
 
     func draw(_ ctx: CGLContextObj) {
+        drawLock.lock()
         updateSurfaceSize()
+
+        let aspectRatioDiff = fabs( (surfaceSize!.width/surfaceSize!.height) -
+                                    (bounds.size.width/bounds.size.height) )
+
+        if aspectRatioDiff <= 0.005 && draw.rawValue >= Draw.atomic.rawValue {
+             if draw == .atomic {
+                draw = .atomicEnd
+             } else {
+                atomicDrawingEnd()
+             }
+        }
+
         mpv.drawGLCB(surfaceSize!)
         CGLFlushDrawable(ctx)
+        drawLock.unlock()
 
         if needsICCUpdate {
             needsICCUpdate = false
@@ -119,6 +136,20 @@ class VideoLayer: CAOpenGLLayer {
         }
     }
 
+    func atomicDrawingStart() {
+        if draw == .normal && hasVideo {
+            NSDisableScreenUpdates()
+            draw = .atomic
+        }
+    }
+
+    func atomicDrawingEnd() {
+        if draw.rawValue >= Draw.atomic.rawValue {
+            NSEnableScreenUpdates()
+            draw = .normal
+        }
+     }
+
     override func copyCGLPixelFormat(forDisplayMask mask: UInt32) -> CGLPixelFormatObj {
         let glVersions: [CGLOpenGLProfile] = [
             kCGLOGLPVersion_3_2_Core,
diff --git a/video/out/cocoa-cb/window.swift b/video/out/cocoa-cb/window.swift
index bd94330dcb..f720205e5c 100644
--- a/video/out/cocoa-cb/window.swift
+++ b/video/out/cocoa-cb/window.swift
@@ -376,7 +376,22 @@ class Window: NSWindow, NSWindowDelegate {
     override func setFrame(_ frameRect: NSRect, display flag: Bool) {
         let newFrame = !isAnimating && isInFullscreen ? targetScreen!.frame :
                                                         frameRect
+        let aspectRatioDiff = fabs( (newFrame.width/newFrame.height) -
+                                    (frame.width/frame.height) )
+
+        let isNotUserLiveResize = isAnimating || !(!isAnimating && inLiveResize)
+        if aspectRatioDiff > 0.005 && isNotUserLiveResize {
+            cocoaCB.layer.drawLock.lock()
+            cocoaCB.layer.atomicDrawingStart()
+        }
+
         super.setFrame(newFrame, display: flag)
+        cocoaCB.layer.neededFlips += 1
+
+        if aspectRatioDiff > 0.005 && isNotUserLiveResize {
+            Swift.print("drawUnLock")
+            cocoaCB.layer.drawLock.unlock()
+        }
 
         if keepAspect {
             contentAspectRatio = unfsContentFrame!.size