iPhone摄像头设备获取

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 Over!!!!

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