try: Improvements from WWDC 2021 1:1 workshop (#197)

* perf: Automatically determine Pixel Format depending on active format. (More efficient video recording 🚀)
* perf: Skip `AVAssetWriter` transform by directly correctly orienting the Video Output connection
* feat: Support camera flipping while recording
* feat: Run frame processor on separate queue, avoids stutters in video recordigns
* feat: Automatically drop late frame processor frames

ios/CameraView.swift

@@ -100,6 +100,9 @@ public final class CameraView: UIView {
   internal let videoQueue = CameraQueues.videoQueue
   internal let audioQueue = CameraQueues.audioQueue
 
+  /// Specifies whether the frameProcessor() function is currently executing. used to drop late frames.
+  internal var isRunningFrameProcessor = false
+
   var isRunning: Bool {
     return captureSession.isRunning
   }