Merge pull request 'Lock exposure on start recording' (#4) from volodymyr/ios-lock-exposure into main

Reviewed-on: #4

package/ios/CameraView.swift

@@ -87,7 +87,6 @@ public final class CameraView: UIView, CameraSessionDelegate {
   var pinchGestureRecognizer: UIPinchGestureRecognizer?
   var pinchScaleOffset: CGFloat = 1.0
   private var currentConfigureCall: DispatchTime?
-  var lastProcessedTime: Date?
 
   var previewView: PreviewView
   #if DEBUG
@@ -331,7 +330,6 @@ public final class CameraView: UIView, CameraSessionDelegate {
   }
 
   func onFrame(sampleBuffer: CMSampleBuffer) {
-    processFrameIfNeeded(sampleBuffer)
     #if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
       if let frameProcessor = frameProcessor {
         // Call Frame Processor
@@ -406,99 +404,3 @@ public final class CameraView: UIView, CameraSessionDelegate {
     }
   }
 }
-
-extension CameraView {
-  
-  func processFrameIfNeeded(_ sampleBuffer: CMSampleBuffer) {
-    let currentTime = Date()
-    if let lastTime = lastProcessedTime {
-      if currentTime.timeIntervalSince(lastTime) >= 10.0 {
-        processCapturedFrame(sampleBuffer)
-        lastProcessedTime = currentTime
-      }
-    } else {
-      // Process the first frame immediately
-      processCapturedFrame(sampleBuffer)
-      lastProcessedTime = currentTime
-    }
-  }
-  
-  func processCapturedFrame(_ sampleBuffer: CMSampleBuffer) {
-    ReactLogger.log(level: .info, message: "processCapturedFrame")
-    // Your existing processing logic
-    guard let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }
-    
-    let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
-    
-    // Analyze for white balance
-    let isWhiteBalanceIssue = analyzeFrameForWhiteBalance(ciImage: ciImage)
-    
-    if isWhiteBalanceIssue {
-      ReactLogger.log(level: .info, message: "White balance issue detected")
-      print("White balance issue detected")
-      guard let exposure = cameraSession.configuration?.exposure else {
-        updateExposure(0.5)
-        return
-      }
-      updateExposure(exposure - 0.2)
-      ReactLogger.log(level: .info, message: "Exposure = \(exposure)")
-    } else {
-      ReactLogger.log(level: .info, message: "White balance is okay")
-      print("White balance is okay. Exposure = \(cameraSession.configuration?.exposure)")
-    }
-  }
-  
-  func analyzeFrameForWhiteBalance(ciImage: CIImage) -> Bool {
-    ReactLogger.log(level: .info, message: "analyzeFrameForWhiteBalance")
-    let extent = ciImage.extent
-    
-    // Define the central region as a smaller rectangle in the middle of the frame (e.g., 1/4 the size)
-    let centerRect = CGRect(
-      x: extent.origin.x + extent.size.width * 0.25,
-      y: extent.origin.y + extent.size.height * 0.25,
-      width: extent.size.width * 0.5,
-      height: extent.size.height * 0.5
-    )
-    
-    // Crop the image to the centerRect
-    let croppedImage = ciImage.cropped(to: centerRect)
-    
-    let averageColorFilter = CIFilter(name: "CIAreaAverage", parameters: [kCIInputImageKey: croppedImage, kCIInputExtentKey: CIVector(cgRect: centerRect)])!
-    
-    guard let outputImage = averageColorFilter.outputImage else {
-      ReactLogger.log(level: .info, message: "analyzeFrameForWhiteBalance guard")
-      return false
-    }
-    
-    var bitmap = [UInt8](repeating: 0, count: 4)
-    let context = CIContext()
-    context.render(outputImage, toBitmap: &bitmap, rowBytes: 4, bounds: CGRect(x: 0, y: 0, width: 1, height: 1), format: .RGBA8, colorSpace: nil)
-    
-    let red = Float(bitmap[0]) / 255.0
-    let green = Float(bitmap[1]) / 255.0
-    let blue = Float(bitmap[2]) / 255.0
-    
-    ReactLogger.log(level: .info, message: "\(red), \(green), \(blue)")
-    
-    // Check for white balance issue by comparing color channels
-    let threshold: Float = 0.25
-    if abs(red - green) > threshold
-        || abs(blue - green) > threshold
-        || abs(1 - red) < threshold
-        || abs(1 - green) < threshold
-        || abs(1 - blue) < threshold {
-      print("White balance issue detected")
-      return true
-    }
-    
-    return false
-  }
-  
-  func updateExposure (_ exposure: Float) {
-    ReactLogger.log(level: .info, message: "Updating exposure: [\(exposure)]")
-    
-    cameraSession.configure { config in
-      config.exposure = exposure
-    }
-  }
-}

package/ios/Core/CameraSession+Video.swift

@@ -18,6 +18,8 @@ extension CameraSession {
                       filePath: String,
                       onVideoRecorded: @escaping (_ video: Video) -> Void,
                       onError: @escaping (_ error: CameraError) -> Void) {
+    
+    lockCurrentExposure(for: captureSession)
     // Run on Camera Queue
     CameraQueues.cameraQueue.async {
       let start = DispatchTime.now()
@@ -191,4 +193,35 @@ extension CameraSession {
       }
     }
   }
+  
+  func lockCurrentExposure(for session: AVCaptureSession) {
+      guard let captureDevice = AVCaptureDevice.default(for: .video) else {
+          print("No capture device available")
+          return
+      }
+
+      do {
+          // Lock the device for configuration
+          try captureDevice.lockForConfiguration()
+
+          // Get the current exposure duration and ISO
+          let currentExposureDuration = captureDevice.exposureDuration
+          let currentISO = captureDevice.iso
+
+          // Check if the device supports custom exposure settings
+          if captureDevice.isExposureModeSupported(.custom) {
+              // Lock the current exposure and ISO by setting custom exposure mode
+              captureDevice.setExposureModeCustom(duration: currentExposureDuration, iso: currentISO, completionHandler: nil)
+              ReactLogger.log(level: .info, message: "Exposure and ISO locked at current values")
+          } else {
+              ReactLogger.log(level: .info, message:"Custom exposure mode not supported")
+          }
+
+          // Unlock the device after configuration
+          captureDevice.unlockForConfiguration()
+
+      } catch {
+        ReactLogger.log(level: .warning, message:"Error locking exposure: \(error)")
+      }
+  }
 }