address a couple data races

CaptureSample/CaptureEngine.swift

@@ -233,7 +233,8 @@ class CaptureEngineStreamOutput: NSObject, SCStreamOutput, SCStreamDelegate {
               let contentScale = attachments[.contentScale] as? CGFloat,
               let scaleFactor = attachments[.scaleFactor] as? CGFloat else { return nil }
 
-        let encoderFrame = self.encoder?.videoSink?.mostRecentSampleBuffer
+        //let encoderFrame = self.encoder?.videoSink?.mostRecentSampleBuffer
+        let encoderFrame: CMSampleBuffer? = nil
 
         // Create a new frame with the relevant data.
         let frame = CapturedFrame(surface: surface,

CaptureSample/Encoder.swift

@@ -30,6 +30,8 @@ class VTEncoder {
     var stoppingEncoding = false
     var pixelTransferBuffer: CVPixelBuffer!
 
+    var hasStartedLock = NSLock()
+
     var destWidth: Int
     var destHeight: Int
 
@@ -180,10 +182,13 @@ class VTEncoder {
     }
 
     func startSession(buffer: CVImageBuffer, timeStamp: CMTime, duration: CMTime, properties: CFDictionary?, infoFlags: UnsafeMutablePointer<VTEncodeInfoFlags>?) throws {
+        self.hasStartedLock.lock()
         guard !self.isStarting else {
+            self.hasStartedLock.unlock()
             return
         }
         self.isStarting = true
+        self.hasStartedLock.unlock()
         guard !self.criticalErrorEncountered else {
             throw self.currentError!
         }
@@ -205,7 +210,9 @@ class VTEncoder {
             if sbuf != nil {
                 do {
                     try self.videoSink.startSession(sbuf!)
+                    self.hasStartedLock.lock()
                     self.hasStarted = true
+                    self.hasStartedLock.unlock()
                     self.isStarting = false
                 } catch {
                     self.currentError = error
@@ -249,10 +256,10 @@ class VTEncoder {
                 (status: OSStatus, infoFlags: VTEncodeInfoFlags, sbuf: CMSampleBuffer?) -> Void in
                 if sbuf != nil {
                     self.videoSink.sendSampleBuffer(sbuf!)
-                    if self.decodes {
+                    /*if self.decodes {
                         self.videoSink.mostRecentSampleBuffer = sbuf!
                         VTDecompressionSessionDecodeFrame(self.decodeSession, sampleBuffer: sbuf!, flags: [._1xRealTimePlayback], infoFlagsOut: nil, outputHandler: self.outputHandler)
-                    }
+                    }*/
                 }
             }
         } else {

CaptureSample/VideoSink.swift

@@ -18,7 +18,7 @@ public class VideoSink {
     var hasStarted = false
 
     var mostRecentImageBuffer: CVImageBuffer?
-    var mostRecentSampleBuffer: CMSampleBuffer?
+    //var mostRecentSampleBuffer: CMSampleBuffer?
 
     private var bookmarkedURL: URL?
 
@@ -33,6 +33,7 @@ public class VideoSink {
     private let usesReplayBuffer: Bool
     private let replayBufferDuration: Int
     private var isActive: Bool
+    private var replayBufferLock = NSLock()
 
     var accessingBookmarkURL = false
 
@@ -265,8 +266,10 @@ public class VideoSink {
     }
 
     func stopReplayBuffer() throws {
+        self.replayBufferLock.lock()
         self.videoReplayBuffer = nil
         self.audioReplayBuffer = nil
+        self.replayBufferLock.unlock()
     }
 
     /// Closes the destination movie file.

README.md

@@ -1,5 +1,5 @@
 # Record
-Record aims to be a low-overhead macOS screen recorder that emphasizes not missing frames, color correctness and color-matching between output color spaces, and a variety of encoder options for size and quality flexibility.
+Record aims to be a low-overhead macOS screen recorder that emphasizes not missing frames, color correctness, and a variety of encoder options for size and quality flexibility.
 
 <img width="1840" alt="Screenshot 2023-08-25 at 7 58 44 PM" src="https://github.com/jcm93/Record/assets/6864788/7e683799-7ff9-4d31-8393-86c4ffa53f07">