recording video with multiple cameras

To record video with multiple cameras, you can utilize the AV Foundation framework, which provides a robust set of APIs for capturing and processing video. Here's a high-level overview of how you can achieve this, particularly focusing on spatial video recording as discussed in the session "Build compelling spatial photo and video experiences" at WWDC 2024.

Steps to Record Video with Multiple Cameras

1. Create an AV Capture Session:

   • Initialize an AVCaptureSession to manage the data flow between the input (camera) and output (movie file).

2. Set Up the Capture Device:

   • Use the built-in dual wide camera, which includes both the wide and ultra-wide cameras. This is essential for spatial video recording.
   • Example code snippet:

     let captureSession = AVCaptureSession()
     guard let captureDevice = AVCaptureDevice.default(.builtInDualWideCamera, for: .video, position: .back) else {
         fatalError("No dual wide camera available")
     }
     

3. Add Input to the Session:

   • Create an AVCaptureDeviceInput with the capture device and add it to the session.
   • Example code snippet:

     do {
         let input = try AVCaptureDeviceInput(device: captureDevice)
         captureSession.addInput(input)
     } catch {
         print("Error adding input: \(error)")
     }
     

4. Add Output to the Session:

   • Create an AVCaptureMovieFileOutput to manage the output and write it to disk.
   • Example code snippet:

     let movieOutput = AVCaptureMovieFileOutput()
     captureSession.addOutput(movieOutput)
     

5. Enable Spatial Video Recording:

   • Check if spatial video capture is supported and enable it.
   • Example code snippet:

     if captureDevice.isSpatialVideoCaptureSupported {
         captureDevice.isSpatialVideoCaptureEnabled = true
     } else {
         print("Spatial video capture not supported on this device")
     }
     

6. Start the Capture Session:

   • Commit the configuration and start running the session.
   • Example code snippet:

     captureSession.commitConfiguration()
     captureSession.startRunning()
     

Additional Enhancements

• Video Stabilization:

  • Set the preferred video stabilization mode to cinematicExtendedEnhanced for smoother videos.
  • Example code snippet:

    if let connection = movieOutput.connection(with: .video) {
        connection.preferredVideoStabilizationMode = .cinematicExtendedEnhanced
    }
    

• Video Preview:

  • Use AVCaptureVideoPreviewLayer to get a video preview feed.
  • Example code snippet:

    let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    previewLayer.videoGravity = .resizeAspectFill
    

For more detailed information and code examples, you can refer to the session "Build compelling spatial photo and video experiences" at WWDC 2024.

Relevant Sessions

1. Build compelling spatial photo and video experiences
2. Explore multiview video playback in visionOS

These sessions provide comprehensive insights into recording and handling video with multiple cameras, including spatial video and multiview playback.