to consider stabilization delay.

HaishinKit.xcodeproj/project.pbxproj

@@ -251,6 +251,7 @@
 		BCB976DF26107B5600C9A649 /* TSField.swift in Sources */ = {isa = PBXBuildFile; fileRef = BCB976DE26107B5600C9A649 /* TSField.swift */; };
 		BCB9773F2621812800C9A649 /* ISOTypeBufferUtil.swift in Sources */ = {isa = PBXBuildFile; fileRef = BCB9773E2621812800C9A649 /* ISOTypeBufferUtil.swift */; };
 		BCB9D79F2BF12AD8008C5B1B /* SampleVideo_360x240_5mb.mp4 in Resources */ = {isa = PBXBuildFile; fileRef = 29B876D91CD70CE700FC07DA /* SampleVideo_360x240_5mb.mp4 */; };
+		BCBF01762CE0AD1D00C63E7A /* FrameTracker.swift in Sources */ = {isa = PBXBuildFile; fileRef = BCBF01752CE0AD1900C63E7A /* FrameTracker.swift */; };
 		BCC1A72B264FAC1800661156 /* ESSpecificData.swift in Sources */ = {isa = PBXBuildFile; fileRef = BCC1A72A264FAC1800661156 /* ESSpecificData.swift */; };
 		BCC2237E2C1468C700F5F234 /* SRTHaishinKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = BCCC45962AA289FA0016EFE8 /* SRTHaishinKit.framework */; };
 		BCC2237F2C1468C700F5F234 /* SRTHaishinKit.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BCCC45962AA289FA0016EFE8 /* SRTHaishinKit.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
@@ -714,6 +715,7 @@
 		BCABED202BDE23C600CC7E73 /* AudioNode+DebugExtension.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AudioNode+DebugExtension.swift"; sourceTree = "<group>"; };
 		BCB976DE26107B5600C9A649 /* TSField.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TSField.swift; sourceTree = "<group>"; };
 		BCB9773E2621812800C9A649 /* ISOTypeBufferUtil.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ISOTypeBufferUtil.swift; sourceTree = "<group>"; };
+		BCBF01752CE0AD1900C63E7A /* FrameTracker.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FrameTracker.swift; sourceTree = "<group>"; };
 		BCC1A72A264FAC1800661156 /* ESSpecificData.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ESSpecificData.swift; sourceTree = "<group>"; };
 		BCC4F4142AD6FC1100954EF5 /* IOTellyUnit.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IOTellyUnit.swift; sourceTree = "<group>"; };
 		BCC9E9082636FF7400948774 /* DataBufferTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DataBufferTests.swift; sourceTree = "<group>"; };
@@ -882,6 +884,7 @@
 				BC0D236C26331BAB001DDA0C /* DataBuffer.swift */,
 				29B876671CD70AB300FC07DA /* DataConvertible.swift */,
 				2976A4851D4903C300B53EF2 /* DeviceUtil.swift */,
+				BCBF01752CE0AD1900C63E7A /* FrameTracker.swift */,
 				BC32E88729C9971100051507 /* InstanceHolder.swift */,
 				2942424C1CF4C01300D65DCB /* MD5.swift */,
 				2942A4F721A9418A004E1BEE /* Running.swift */,
@@ -1861,6 +1864,7 @@
 				BC11023E2917C35B00D48035 /* CVPixelBufferPool+Extension.swift in Sources */,
 				29C2631C1D0083B50098D4EF /* IOVideoUnit.swift in Sources */,
 				29B876B41CD70B2800FC07DA /* RTMPSharedObject.swift in Sources */,
+				BCBF01762CE0AD1D00C63E7A /* FrameTracker.swift in Sources */,
 				2901A4EE1D437170002BBD23 /* MediaLink.swift in Sources */,
 				29B876941CD70AFE00FC07DA /* SoundTransform.swift in Sources */,
 				29DF20662312A436004057C3 /* RTMPSocketCompatible.swift in Sources */,

HaishinKit.xcodeproj/xcshareddata/xcschemes/Example iOS.xcscheme

@@ -34,6 +34,8 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      disableMainThreadChecker = "YES"
+      disablePerformanceAntipatternChecker = "YES"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"

Sources/IO/IOVideoMixer.swift

@@ -41,6 +41,9 @@ final class IOVideoMixer<T: IOVideoMixerDelegate> {
             for screen in screens where screen.track == track {
                 screen.enqueue(sampleBuffer)
             }
+            if settings.mainTrack == track {
+                screen.videoPresentationTimeStamp = sampleBuffer.presentationTimeStamp
+            }
         case .passthrough:
             if settings.mainTrack == track {
                 outputSampleBuffer(sampleBuffer)
@@ -62,6 +65,9 @@ final class IOVideoMixer<T: IOVideoMixerDelegate> {
         for screen in screens where screen.track == track {
             screen.reset()
         }
+        if settings.mainTrack == track {
+            screen.videoPresentationTimeStamp = .invalid
+        }
     }
 
     @inline(__always)

Sources/IO/IOVideoUnit.swift

@@ -177,15 +177,13 @@ final class IOVideoUnit: IOUnit {
             }
             let capture = self.capture(for: track)
             configuration?(capture, nil)
+            videoMixer.reset(track)
             try capture?.attachDevice(device, videoUnit: self)
         }
         if device != nil && view != nil {
             // Start captureing if not running.
             mixer?.session.startRunning()
         }
-        if device == nil {
-            videoMixer.reset(track)
-        }
     }
 
     #if os(iOS) || os(tvOS) || os(macOS)

Sources/Screen/Choreographer.swift

@@ -118,11 +118,15 @@ final class DisplayLinkChoreographer: NSObject, Choreographer {
     }
     weak var delegate: (any ChoreographerDelegate)?
     var isRunning: Atomic<Bool> = .init(false)
-    var preferredFramesPerSecond = DisplayLinkChoreographer.preferredFramesPerSecond
+    var preferredFramesPerSecond = DisplayLinkChoreographer.preferredFramesPerSecond {
+        didSet {
+            displayLink?.preferredFramesPerSecond = preferredFramesPerSecond
+        }
+    }
     private var displayLink: DisplayLink? {
         didSet {
             oldValue?.invalidate()
-            guard let displayLink = displayLink else {
+            guard let displayLink else {
                 return
             }
             displayLink.isPaused = true

Sources/Screen/Screen.swift

@@ -58,7 +58,7 @@ public final class Screen: ScreenObjectContainerConvertible {
         return choreographer.isRunning
     }
 
-    public var delayTime: TimeInterval = (1 / 33)
+    var videoPresentationTimeStamp: CMTime = .invalid
 
     #if os(macOS)
     /// Specifies the background color.
@@ -81,6 +81,7 @@ public final class Screen: ScreenObjectContainerConvertible {
         }
     }
     #endif
+
     weak var observer: (any ScreenObserver)?
     private var root: ScreenObjectContainer = .init()
     private(set) var renderer = ScreenRendererByCPU()
@@ -89,7 +90,7 @@ public final class Screen: ScreenObjectContainerConvertible {
         choreographer.delegate = self
         return choreographer
     }()
-    private var timeStamp: CMTime = .invalid
+    private var timeStamp: CMTime = .zero
     private var attributes: [NSString: NSObject] {
         return [
             kCVPixelBufferPixelFormatTypeKey: NSNumber(value: kCVPixelFormatType_32ARGB),
@@ -177,7 +178,12 @@ extension Screen: ChoreographerDelegate {
         if let dictionary = CVBufferGetAttachments(pixelBuffer, .shouldNotPropagate) {
             CVBufferSetAttachments(pixelBuffer, dictionary, .shouldPropagate)
         }
-        let now = CMTime(seconds: timestamp - delayTime, preferredTimescale: 1000000000)
+        let now = videoPresentationTimeStamp == .invalid ?
+            CMTime(seconds: timestamp, preferredTimescale: 1000000000) :
+            videoPresentationTimeStamp
+        guard timeStamp < now else {
+            return
+        }
         var timingInfo = CMSampleTimingInfo(
             duration: timeStamp == .invalid ? .zero : now - timeStamp,
             presentationTimeStamp: now,

Sources/Screen/ScreenObject.swift

@@ -230,6 +230,10 @@ public final class VideoTrackScreenObject: ScreenObject, ChromaKeyProcessable {
         }
     }
 
+    public var frameRate: Int {
+        frameTracker.frameRate
+    }
+
     override var blendMode: ScreenObject.BlendMode {
         if 0.0 < cornerRadius || chromaKeyColor != nil {
             return .alpha
@@ -239,6 +243,7 @@ public final class VideoTrackScreenObject: ScreenObject, ChromaKeyProcessable {
 
     private var queue: TypedBlockQueue<CMSampleBuffer>?
     private var effects: [VideoEffect] = .init()
+    private var frameTracker = FrameTracker()
 
     /// Create a screen object.
     override public init() {
@@ -270,10 +275,11 @@ public final class VideoTrackScreenObject: ScreenObject, ChromaKeyProcessable {
     }
 
     override public func makeImage(_ renderer: some ScreenRenderer) -> CGImage? {
-        guard let sampleBuffer = queue?.query(renderer.presentationTimeStamp),
+        guard let sampleBuffer = queue?.dequeue(renderer.presentationTimeStamp),
               let pixelBuffer = sampleBuffer.imageBuffer else {
             return nil
         }
+        frameTracker.update(sampleBuffer.presentationTimeStamp)
         // Resizing before applying the filter for performance optimization.
         var image = CIImage(cvPixelBuffer: pixelBuffer).transformed(by: videoGravity.scale(
             bounds.size,
@@ -306,12 +312,20 @@ public final class VideoTrackScreenObject: ScreenObject, ChromaKeyProcessable {
         }
     }
 
+    override public func draw(_ renderer: some ScreenRenderer) {
+        super.draw(renderer)
+        if queue?.isEmpty == false {
+            invalidateLayout()
+        }
+    }
+
     func enqueue(_ sampleBuffer: CMSampleBuffer) {
         try? queue?.enqueue(sampleBuffer)
         invalidateLayout()
     }
 
     func reset() {
+        frameTracker.clear()
         try? queue?.reset()
         invalidateLayout()
     }

Sources/Util/FrameTracker.swift

@@ -0,0 +1,27 @@
+import CoreMedia
+
+struct FrameTracker {
+    static let seconds = 1.0
+
+    private(set) var frameRate: Int = 0
+    private var count = 0
+    private var rotated: CMTime = .zero
+
+    init() {
+    }
+
+    mutating func update(_ time: CMTime) {
+        count += 1
+        if Self.seconds <= (time - rotated).seconds {
+            rotated = time
+            frameRate = count
+            count = 0
+            logger.info(frameRate)
+        }
+    }
+
+    mutating func clear() {
+        count = 0
+        rotated = .zero
+    }
+}

Sources/Util/TypedBlockQueue.swift

@@ -48,7 +48,7 @@ final class TypedBlockQueue<T: AnyObject> {
 }
 
 extension TypedBlockQueue where T == CMSampleBuffer {
-    func query(_ presentationTimeStamp: CMTime) -> CMSampleBuffer? {
+    func dequeue(_ presentationTimeStamp: CMTime) -> CMSampleBuffer? {
         var result: CMSampleBuffer?
         while !queue.isEmpty {
             guard let head else {