摄像头打开时自动开始录像？

Question

I have read lots of tutorials for video player. But How to start recording when camera open in a custom view with time limit.

Answer 1

Here is the working solution with a swift version

var session: AVCaptureSession?
var userreponsevideoData = NSData()
var userreponsethumbimageData = NSData()

override func viewDidLoad() {
    super.viewDidLoad()
     createSession()
}

func for stopRecording(){
  session?.stopRunning()
}

func createSession() {

var input: AVCaptureDeviceInput?
let  movieFileOutput = AVCaptureMovieFileOutput()
videosPreviewLayer?.frame.size = photoPreviewImageView.frame.size
session = AVCaptureSession()
let error: NSError? = nil
do { input = try AVCaptureDeviceInput(device: self.cameraWithPosition(position: .back)!) } catch {return}
if error == nil {
    session?.addInput(input!)
} else {
    print("camera input error: \(String(describing: error))")
}
videosPreviewLayer = AVCaptureVideoPreviewLayer(session: session!)
videosPreviewLayer?.frame.size = self.photoPreviewImageView.frame.size
videosPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videosPreviewLayer?.connection?.videoOrientation = .portrait
photoPreviewImageView.layer.sublayers?.forEach { $0.removeFromSuperlayer() }
photoPreviewImageView.layer.addSublayer(videosPreviewLayer!)

switchCameraButton.isHidden=true
flashButton.isHidden=true
msgLabel.isHidden=true
galleryCollectionView.isHidden=true
timerLabel.isHidden=false

let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
fileURL = URL(string:"\(documentsURL.appendingPathComponent("temp"))" + ".mov")
print("*****fileurl%@",fileURL ?? "00000")

let maxDuration: CMTime = CMTimeMake(600, 10)
movieFileOutput.maxRecordedDuration = maxDuration
movieFileOutput.minFreeDiskSpaceLimit = 1024 * 1024
if self.session!.canAddOutput(movieFileOutput) {
    self.session!.addOutput(movieFileOutput)
}
session?.startRunning()
movieFileOutput.startRecording(to: fileURL!, recordingDelegate: self)
}

func cameraWithPosition(position: AVCaptureDevice.Position) -> AVCaptureDevice? {
let devices = AVCaptureDevice.devices(for: AVMediaType.video)
for device in devices {
    if device.position == position {
        return device
    }
}
return nil
}
}
extension SwipeGallerymainViewController: AVCaptureFileOutputRecordingDelegate
{

func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
print(outputFileURL)
let filemainurl = outputFileURL

do
{
    let asset = AVURLAsset(url:filemainurl as URL, options:nil)
    print(asset)
    let imgGenerator = AVAssetImageGenerator(asset: asset)
    imgGenerator.appliesPreferredTrackTransform = true
    let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(0, 1), actualTime: nil)
    let uiImage = UIImage(cgImage: cgImage)
    previewImage = uiImage
    userreponsethumbimageData = NSData(contentsOf: filemainurl as URL)!
    print(userreponsethumbimageData.length)
    print(uiImage)

}
catch let error as NSError
{
    print(error)
    return
}
let VideoFilePath = URL(fileURLWithPath:NSTemporaryDirectory()).appendingPathComponent("mergeVideo\(arc4random()%1000)d").appendingPathExtension("mp4").absoluteString
if FileManager.default.fileExists(atPath: VideoFilePath)
{
    print("exist")
    do
    {
        try FileManager.default.removeItem(atPath: VideoFilePath)
    }
    catch { }
}

let tempfilemainurl =  NSURL(string: VideoFilePath)!
let sourceAsset = AVURLAsset(url:filemainurl as URL, options:nil)
let assetExport: AVAssetExportSession = AVAssetExportSession(asset: sourceAsset, presetName: AVAssetExportPresetMediumQuality)!
assetExport.outputFileType = AVFileType.mov
assetExport.outputURL = tempfilemainurl as URL
assetExport.exportAsynchronously { () -> Void in
    switch assetExport.status
    {
    case AVAssetExportSessionStatus.completed:
        DispatchQueue.main.async {
            do
            {

                self.userreponsevideoData = try NSData(contentsOf: tempfilemainurl as URL, options: NSData.ReadingOptions())
                print("MB - \(self.userreponsevideoData.length) byte")
                self.isVideoLoad=true
                self.performSegue(withIdentifier:"previewSegue", sender:self)
            }
            catch
            {

                print(error)
            }
        }

    case  AVAssetExportSessionStatus.failed:
        print("failed \(String(describing: assetExport.error))")
    case AVAssetExportSessionStatus.cancelled:
        print("cancelled \(String(describing: assetExport.error))")
    default:
        print("complete")

    }

}
}

 func captureOutput(captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAtURL fileURL: NSURL!, fromConnections connections: [AnyObject]!) {
print(fileURL)
}


}

Answer 2

I have done same thing in java using Robot class on laptop. Robot class is capable of sending keystrokes and mouse movements automatically. You can try same thing on your platform. Automate the button press event so that recording get started.