转载自 http://blog.csdn.net/linzhiji/article/details/6730693
目的：打开、关闭前置摄像头，绘制图像，并获取摄像头的二进制数据。需要的库AVFoundation.framework 、CoreVideo.framework 、CoreMedia.framework 、QuartzCore.framework该摄像头捕抓必须编译真机的版本，模拟器下编译不了。
函数说明
- (void)createControl{// UI界面控件的创建}
- (AVCaptureDevice *)getFrontCamera;获取前置摄像头设备
- (void)startVideoCapture;打开摄像头并开始捕捉图像其中代码：
AVCaptureVideoPreviewLayer* previewLayer = [AVCaptureVideoPreviewLayer layerWithSession: self->avCaptureSession];
previewLayer.frame = localView.bounds;
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
[self->localView.layer addSublayer: previewLayer];
为把图片画到UIView里面
- (void)stopVideoCapture:(id)arg；关闭摄像头，停止捕抓图像其中代码：
for(UIView*viewinself->localView.subviews) {[viewremoveFromSuperview];}
为移除摄像头图像的View详情见代码，代码拷过去可以直接使用
代码：头文件：
// // AVCallController.h // Pxlinstall // // Created by Lin Charlie C. on 11-3-24. // Copyright 2011 xxxx. All rights reserved. // #import <UIKit/UIKit.h> #import <AVFoundation/AVFoundation.h> @interface AVCallController : UIViewController <AVCaptureVideoDataOutputSampleBufferDelegate> { //UI UILabel*labelState; UIButton*btnStartVideo; UIView*localView; AVCaptureSession* avCaptureSession; AVCaptureDevice *avCaptureDevice; BOOLfirstFrame; //是否为第一帧 intproducerFps; } @property (nonatomic, retain) AVCaptureSession *avCaptureSession; @property (nonatomic, retain) UILabel *labelState; - (void)createControl; - (AVCaptureDevice *)getFrontCamera; - (void)startVideoCapture; - (void)stopVideoCapture:(id)arg; @end
实现文件：
// AVCallController.m // Pxlinstall // // Created by Lin Charlie C. on 11-3-24. // Copyright 2011 高鸿移通. All rights reserved. // #import "AVCallController.h" @implementation AVCallController @synthesize avCaptureSession; @synthesize labelState; // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. /* - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization. } return self; } */ -(id)init { if(self= [superinit]) { firstFrame= YES; producerFps= 50; } returnself; } // Implement loadView to create a view hierarchy programmatically, without using a nib. - (void)loadView { [superloadView]; [selfcreateControl]; } /* // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } */ /* // Override to allow orientations other than the default portrait orientation. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations. return (interfaceOrientation == UIInterfaceOrientationPortrait); } */ - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [superdidReceiveMemoryWarning]; // Release any cached data, images, etc. that aren't in use. } - (void)viewDidUnload { [superviewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [super dealloc]; } #pragma mark - #pragma mark createControl - (void)createControl { //UI展示 self.view.backgroundColor= [UIColorgrayColor]; labelState= [[UILabelalloc] initWithFrame:CGRectMake(10, 20, 220, 30)]; labelState.backgroundColor= [UIColorclearColor]; [self.viewaddSubview:labelState]; [labelStaterelease]; btnStartVideo= [[UIButtonalloc] initWithFrame:CGRectMake(20, 350, 80, 50)]; [btnStartVideosetTitle:@"Star"forState:UIControlStateNormal]; [btnStartVideosetBackgroundImage:[UIImageimageNamed:@"Images/button.png"] forState:UIControlStateNormal]; [btnStartVideoaddTarget:selfaction:@selector(startVideoCapture) forControlEvents:UIControlEventTouchUpInside]; [self.viewaddSubview:btnStartVideo]; [btnStartVideorelease]; UIButton* stop = [[UIButtonalloc] initWithFrame:CGRectMake(120, 350, 80, 50)]; [stop setTitle:@"Stop"forState:UIControlStateNormal]; [stop setBackgroundImage:[UIImageimageNamed:@"Images/button.png"] forState:UIControlStateNormal]; [stop addTarget:selfaction:@selector(stopVideoCapture:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:stop]; [stop release]; localView= [[UIViewalloc] initWithFrame:CGRectMake(40, 50, 200, 300)]; [self.viewaddSubview:localView]; [localViewrelease]; } #pragma mark - #pragma mark VideoCapture - (AVCaptureDevice *)getFrontCamera { //获取前置摄像头设备 NSArray *cameras = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]; for (AVCaptureDevice *device in cameras) { if (device.position == AVCaptureDevicePositionFront) return device; } return [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; } - (void)startVideoCapture { //打开摄像设备，并开始捕抓图像 [labelStatesetText:@"Starting Video stream"]; if(self->avCaptureDevice|| self->avCaptureSession) { [labelStatesetText:@"Already capturing"]; return; } if((self->avCaptureDevice = [self getFrontCamera]) == nil) { [labelStatesetText:@"Failed to get valide capture device"]; return; } NSError *error = nil; AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:self->avCaptureDevice error:&error]; if (!videoInput) { [labelStatesetText:@"Failed to get video input"]; self->avCaptureDevice= nil; return; } self->avCaptureSession = [[AVCaptureSession alloc] init]; self->avCaptureSession.sessionPreset = AVCaptureSessionPresetLow; [self->avCaptureSession addInput:videoInput]; // Currently, the only supported key is kCVPixelBufferPixelFormatTypeKey. Recommended pixel format choices are // kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange or kCVPixelFormatType_32BGRA. // On iPhone 3G, the recommended pixel format choices are kCVPixelFormatType_422YpCbCr8 or kCVPixelFormatType_32BGRA. // AVCaptureVideoDataOutput *avCaptureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init]; NSDictionary*settings = [[NSDictionaryalloc] initWithObjectsAndKeys: //[NSNumber numberWithUnsignedInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange], kCVPixelBufferPixelFormatTypeKey, [NSNumbernumberWithInt:240], (id)kCVPixelBufferWidthKey, [NSNumber numberWithInt:320], (id)kCVPixelBufferHeightKey, nil]; avCaptureVideoDataOutput.videoSettings = settings; [settings release]; avCaptureVideoDataOutput.minFrameDuration = CMTimeMake(1, self->producerFps); /*We create a serial queue to handle the processing of our frames*/ dispatch_queue_tqueue = dispatch_queue_create("org.doubango.idoubs", NULL); [avCaptureVideoDataOutput setSampleBufferDelegate:self queue:queue]; [self->avCaptureSession addOutput:avCaptureVideoDataOutput]; [avCaptureVideoDataOutput release]; dispatch_release(queue); AVCaptureVideoPreviewLayer* previewLayer = [AVCaptureVideoPreviewLayer layerWithSession: self->avCaptureSession]; previewLayer.frame = localView.bounds; previewLayer.videoGravity= AVLayerVideoGravityResizeAspectFill; [self->localView.layer addSublayer: previewLayer]; self->firstFrame= YES; [self->avCaptureSession startRunning]; [labelStatesetText:@"Video capture started"]; } - (void)stopVideoCapture:(id)arg { //停止摄像头捕抓 if(self->avCaptureSession){ [self->avCaptureSession stopRunning]; self->avCaptureSession= nil; [labelStatesetText:@"Video capture stopped"]; } self->avCaptureDevice= nil; //移除localView里面的内容 for(UIView*viewinself->localView.subviews) { [viewremoveFromSuperview]; } } #pragma mark - #pragma mark AVCaptureVideoDataOutputSampleBufferDelegate - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { //捕捉数据输出 要怎么处理虽你便 CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); /*Lock the buffer*/ if(CVPixelBufferLockBaseAddress(pixelBuffer, 0) == kCVReturnSuccess) { UInt8 *bufferPtr = (UInt8 *)CVPixelBufferGetBaseAddress(pixelBuffer); size_t buffeSize = CVPixelBufferGetDataSize(pixelBuffer); if(self->firstFrame) { if(1) { //第一次数据要求：宽高，类型 int width = CVPixelBufferGetWidth(pixelBuffer); int height = CVPixelBufferGetHeight(pixelBuffer); int pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer); switch (pixelFormat) { casekCVPixelFormatType_420YpCbCr8BiPlanarVideoRange: //TMEDIA_PRODUCER(producer)->video.chroma = tmedia_nv12; // iPhone 3GS or 4 NSLog(@"Capture pixel format=NV12"); break; casekCVPixelFormatType_422YpCbCr8: //TMEDIA_PRODUCER(producer)->video.chroma = tmedia_uyvy422; // iPhone 3 NSLog(@"Capture pixel format=UYUY422"); break; default: //TMEDIA_PRODUCER(producer)->video.chroma = tmedia_rgb32; NSLog(@"Capture pixel format=RGB32"); break; } self->firstFrame = NO; } } /*We unlock the buffer*/ CVPixelBufferUnlockBaseAddress(pixelBuffer, 0); } /*We create an autorelease pool because as we are not in the main_queue our code is not executed in the main thread. So we have to create an autorelease pool for the thread we are in*/ // NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; // // CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); // /*Lock the image buffer*/ // CVPixelBufferLockBaseAddress(imageBuffer,0); // /*Get information about the image*/ // uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer); // size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); // size_t width = CVPixelBufferGetWidth(imageBuffer); // size_t height = CVPixelBufferGetHeight(imageBuffer); // // /*Create a CGImageRef from the CVImageBufferRef*/ // CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); // CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); // CGImageRef newImage = CGBitmapContextCreateImage(newContext); // // /*We release some components*/ // CGContextRelease(newContext); // CGColorSpaceRelease(colorSpace); // // /*We display the result on the custom layer. All the display stuff must be done in the main thread because // UIKit is no thread safe, and as we are not in the main thread (remember we didn't use the main_queue) // we use performSelectorOnMainThread to call our CALayer and tell it to display the CGImage.*/ // [self.customLayer performSelectorOnMainThread:@selector(setContents:) withObject: (id) newImage waitUntilDone:YES]; // // /*We display the result on the image view (We need to change the orientation of the image so that the video is displayed correctly). // Same thing as for the CALayer we are not in the main thread so ...*/ // UIImage *image= [UIImage imageWithCGImage:newImage scale:1.0 orientation:UIImageOrientationRight]; // // /*We relase the CGImageRef*/ // CGImageRelease(newImage); // // [self.imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:YES]; // // /*We unlock the image buffer*/ // CVPixelBufferUnlockBaseAddress(imageBuffer,0); // // [pool drain]; } @end