iPhone如何使用私有库PhotoLibrary中的类PLCameraController

iPhone:Using PLCameraController

The PLCameraController class is for controlling iPhone's built-in camera and one of Apple's private frameworks. If you want to get the preview of incoming video stream from the camera, it is quite easy to do it. Here are steps to do it. 

1. Get the header of PLCameraController. This can be obtained by dumping iPhone OS frame works by using class-dump-X, or you can download it from somewhere.  

2. Add the PhotoLibrary framework from the SDK directory. With the SDK 2.2.1, the framework is in /Developer/Platforms/iPhoneOS.platform/ Developer/SDKs/iPhoneOS2.0.sdk/System/Library/

PrivateFrameworks/PhotoLibrary.framework

3. Import the PLCameraController header to your application delegate. 

4. Add the following code to 'applicationDidFinishLaunching' 

- (void)applicationDidFinishLaunching:(UIApplication *)application { 

// Hide the status bar 

[[UIApplication sharedApplication] setStatusBarHidden:YES animated:NO];

// Get the view for preview and start preview 

PLCameraController *cam = [PLCameraController sharedInstance]; 

UIView *view = [cam previewView]; 

[cam startPreview]; 

// Add the preview view to window 

[window addSubview:view]; 

// Override point for customization after app launch 

[window makeKeyAndVisible]; 

} 

Now, run the application then you will see something like the screen show below. 

Basically, the resolution of the video coming from the camera is 304x400, which is a little weird. The preview video stream is resized in the preview view. If we do not set a new frame size, it is resized with a fixed aspect ratio and thus, there are white area at the bottom of the screen. 

For full screen preview, set the frame size of the preview view like this : 

view.frame = CGRectMake(0,0, 320, 480) ;

Update :  I tried several tests and it turns out that the preview is actually 304x400.