使用 AVCaptureSession 开始录制视频

Question

我已经创建了 AVCaptureSession 和预览层，但是如何开始录制视频？

这是我的代码..

AVCaptureSession *session = [[AVCaptureSession alloc] init];
[session setSessionPreset:AVCaptureSessionPresetPhoto];

AVCaptureDevice *inputDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];


AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:inputDevice error:&error];

if ([session canAddInput:deviceInput]) {
    [session addInput:deviceInput];
}

AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

[previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
CALayer *rootLayer = [[self view] layer];
[rootLayer setMasksToBounds:YES];
CGRect frame = self.view.frame;

[previewLayer setFrame:frame];

[rootLayer insertSublayer:previewLayer atIndex:0];

AVCaptureVideoDataOutput *videoOutput = [[AVCaptureVideoDataOutput alloc] init];
    videoOutput.videoSettings = nil;
    [session addOutput:videoOutput];
    [session startRunning];

现在我希望它在我按下按钮时开始录制，并且在我完成录制后，它将视频保存在相机胶卷中，那该怎么做呢？

谢谢。

Answer 1

如果你想记录你可以使用一个文件，你可以使用AVCaptureMovieFileOutput，像这样添加到你的 AVCaptureSession

 AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

    if ([session canAddOutput:movieFileOutput]) {
        [session addOutput:movieFileOutput];
    }

然后使用AVCaptureMovileFileOutput方法startRecordingToOutputFileURL开始录制到某个URL..

希望有帮助

丹尼尔

Answer 2

按下按钮，初始化AVCaptureMovieFileOutput，然后通过提供outputFilePath调用startRecordingToOutputFileURL

AVCaptureMovieFileOutput *movieFileOutput;

// Initialization
// Start recording with Path
[movieFileOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputFilePath] recordingDelegate:self];


// Override the callback method
(void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{

    // Use ALAssetsLibrary to save recorded video to Photo Album
    [[[ALAssetsLibrary alloc] init] writeVideoAtPathToSavedPhotosAlbum:outputFileURL completionBlock:^(NSURL *assetURL, NSError *error) {

    }];
}

Answer 3

用 swift 版本试试这个：

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)
}


}