From: Andreas Pehrson <apehrson@mozilla.com>
Date: Thu, 12 Sep 2024 22:36:00 +0000
Subject: Bug 1918096 - In ScreenCapturerSck skip some processing when
 possible. r=webrtc-reviewers,ng

No need to update the last frame unless it has changed.

Differential Revision: https://phabricator.services.mozilla.com/D221942
Mercurial Revision: https://hg.mozilla.org/mozilla-central/rev/8d52f2fd575479da72508033b3a2151906e2bf19
---
 .../desktop_capture/mac/screen_capturer_sck.mm | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/modules/desktop_capture/mac/screen_capturer_sck.mm b/modules/desktop_capture/mac/screen_capturer_sck.mm
index 1a84a39c9c..92c7dadebe 100644
--- a/modules/desktop_capture/mac/screen_capturer_sck.mm
+++ b/modules/desktop_capture/mac/screen_capturer_sck.mm
@@ -556,6 +556,7 @@ void ScreenCapturerSck::OnNewIOSurface(IOSurfaceRef io_surface,
   CGRect contentRect = {};
   CGRect boundingRect = {};
   CGRect overlayRect = {};
+  SCFrameStatus status = SCFrameStatusStopped;
   const auto* dirty_rects = (NSArray*)attachment[SCStreamFrameInfoDirtyRects];
   if (auto factor = (NSNumber*)attachment[SCStreamFrameInfoScaleFactor]) {
     scaleFactor = [factor floatValue];
@@ -584,6 +585,23 @@ void ScreenCapturerSck::OnNewIOSurface(IOSurfaceRef io_surface,
     }
   }
 
+  if (auto statusNr = (NSNumber*)attachment[SCStreamFrameInfoStatus]) {
+    status = (SCFrameStatus)[statusNr integerValue];
+  }
+
+  switch (status) {
+    case SCFrameStatusBlank:
+    case SCFrameStatusIdle:
+    case SCFrameStatusSuspended:
+    case SCFrameStatusStopped:
+      // No new frame. Ignore.
+      return;
+    case SCFrameStatusComplete:
+    case SCFrameStatusStarted:
+      // New frame. Process it.
+      break;
+  }
+
   auto imgBoundingRect = CGRectMake(scaleFactor * boundingRect.origin.x,
                                     scaleFactor * boundingRect.origin.y,
                                     scaleFactor * boundingRect.size.width,