Ios UIImagePickerController在有活动AVSession时变慢_Ios_Cocoa Touch_Uiimagepickercontroller_Avcapturesession

Ios UIImagePickerController在有活动AVSession时变慢

ios cocoa-touch

Ios UIImagePickerController在有活动AVSession时变慢,ios,cocoa-touch,uiimagepickercontroller,avcapturesession,Ios,Cocoa Touch,Uiimagepickercontroller,Avcapturesession,我有一个UIImagePickerController，可用于在我的社交网络应用程序中上载个人资料图像单独使用时工作正常，即没有其他摄像头干扰在另一个视图中，我使用AVCaptureSession和AVCaptureVideoPreviewLayer将相机视图嵌入视图中。在这里，用户可以上传他们拍摄的各种照片单独使用时，也可以正常工作，即没有其他摄像头干扰（这是一个选项卡栏应用程序）无论何时AVCapturePreviewLayer处于活动状态，并且我使用UIImagePickerCo

我有一个

UIImagePickerController

，可用于在我的社交网络应用程序中上载个人资料图像

单独使用时工作正常，即没有其他摄像头干扰

在另一个视图中，我使用

AVCaptureSession

和

AVCaptureVideoPreviewLayer

将相机视图嵌入视图中。在这里，用户可以上传他们拍摄的各种照片

单独使用时，也可以正常工作，即没有其他摄像头干扰

（这是一个选项卡栏应用程序）

无论何时

AVCapturePreviewLayer

处于活动状态，并且我使用

UIImagePickerController

进入视图，imagePicker都需要很长时间才能加载，有时甚至会冻结

这就是我初始化AVSession/AVCapturePreviewLayer的方法：

self.session = [[AVCaptureSession alloc] init];
self.session.sessionPreset = AVCaptureSessionPreset640x480;

self.captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
self.captureVideoPreviewLayer.frame = self.cameraView.bounds;

[self.captureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[self.cameraView.layer addSublayer:self.captureVideoPreviewLayer];


AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;

AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
    // Handle the error appropriately.
    NSLog(@"ERROR: trying to open camera: %@", error);
}else
    [self.session addInput:input];


self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:outputSettings];
[self.session addOutput:self.stillImageOutput];

self.picker = [[UIImagePickerController alloc] init];
self.picker.delegate = self;
self.picker.allowsEditing = YES;
self.picker.sourceType = UIImagePickerControllerSourceTypeCamera;

[self presentViewController:self.picker animated:YES completion:NULL];

以下是初始化UIImagePickerController的方法：

self.session = [[AVCaptureSession alloc] init];
self.session.sessionPreset = AVCaptureSessionPreset640x480;

self.captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
self.captureVideoPreviewLayer.frame = self.cameraView.bounds;

[self.captureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[self.cameraView.layer addSublayer:self.captureVideoPreviewLayer];


AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;

AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
    // Handle the error appropriately.
    NSLog(@"ERROR: trying to open camera: %@", error);
}else
    [self.session addInput:input];


self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:outputSettings];
[self.session addOutput:self.stillImageOutput];

self.picker = [[UIImagePickerController alloc] init];
self.picker.delegate = self;
self.picker.allowsEditing = YES;
self.picker.sourceType = UIImagePickerControllerSourceTypeCamera;

[self presentViewController:self.picker animated:YES completion:NULL];

为什么当previewLayer在另一个视图中处于活动状态时，
```
UIImagePickerController
```
要花很长时间才能加载
如何缩短
```
UIImagePickerController
```
的加载时间

[AVSession stopRunning];