#import <UIKit/UIKit.h>#import <AVFoundation/AVFoundation.h>       //导入 - "视频流"@interface MCViewController : UIViewController<AVCaptureVideoDataOutputSampleBufferDelegate>@property (strong, nonatomic) AVCaptureSession * captureSession;            //AVCaptureSession实例@property (strong, nonatomic) AVCaptureDeviceInput * videoInput;            //持有视频输入实例@property (strong, nonatomic) AVCaptureStillImageOutput * stillImageOutput;  //持有静态图像输出实例@end

////  MCViewController.m//  MyCamera#import "MCViewController.h"@interface MCViewController ()@end@implementation MCViewController#pragma mark - life cycle- (void)viewWillAppear:(BOOL)animated{    [super viewWillAppear:animated];        //开始扑捉会话    [self.captureSession startRunning];}- (void)viewWillDisappear:(BOOL)animated{    [super viewWillDisappear:animated];        //停止扑捉会话    [self.captureSession stopRunning];}- (void)viewDidLoad{    [super viewDidLoad];        //初始化视频流    [self initAv];        //添加拍照按钮    [self addCaptureButton];}#pragma mark - 初始化视频流- (void) initAv{    //1.1 创建AVCaptureSession    self.captureSession = [[AVCaptureSession alloc] init];    //1.2 指定输入设备。这里使用后摄像头。    AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];    //1.3 创建AVCaptureDeviceInput的实例，将所选设备作为扑捉会话的输入。    //      此外，在将是其添加到回话前请创建好输入，这里需要做个检查。    NSError * error = nil;    self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];    if (self.videoInput) {        [self.captureSession addInput:self.videoInput];    }    else    {        NSLog(@"input error : %@", error);    }        //4. 视频流帧数据    AVCaptureVideoDataOutput * output = [[AVCaptureVideoDataOutput alloc] init];    [self.captureSession addOutput:output];        dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);    [output setSampleBufferDelegate:self queue:queue];    //dispatch_release(queue);        //    output.videoSettings = [NSDictionary dictionaryWithObject:    //                                                       [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]    //                                                       forKey:(id)kCVPixelBufferPixelFormatTypeKey];        output.videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:                            [NSNumber numberWithInt:kCVPixelFormatType_32BGRA], kCVPixelBufferPixelFormatTypeKey,                            [NSNumber numberWithInt: 320], (id)kCVPixelBufferWidthKey,                            [NSNumber numberWithInt: 240], (id)kCVPixelBufferHeightKey,                            nil];    //output.minFrameDuration = CMTimeMake(1, 15);            //2. 创建预览层    AVCaptureVideoPreviewLayer * previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];    UIView * aView = self.view;    previewLayer.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);    previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;    [aView.layer addSublayer:previewLayer];    [previewLayer setAffineTransform:CGAffineTransformMakeScale(5.0, 5.0)]; //3. 实现拍照    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];    NSDictionary * stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil];    [self.stillImageOutput setOutputSettings:stillImageOutputSettings];    [self.captureSession addOutput:self.stillImageOutput];        //    //4. 拍照变焦//    AVCaptureConnection * stillImageConnection = [self connectionWithMediaType:AVMediaTypeVideo fromConnections:[self.stillImageOutput connections]];//    //    [stillImageConnection setVideoScaleAndCropFactor:5.0];             }#pragma  mark - - (AVCaptureConnection *)connectionWithMediaType:(NSString *)mediaType fromConnections:(NSArray *)connections{    for ( AVCaptureConnection *connection in connections )    {        for ( AVCaptureInputPort *port in [connection inputPorts] )        {            if ( [[port mediaType] isEqual:mediaType] )            {                return connection;            }        }    }    return nil;}#pragma mark -  delegate -  AVCaptureVideoDataOutputSampleBufferDelegate- (void)captureOutput:(AVCaptureOutput *)captureOutputdidOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer       fromConnection:(AVCaptureConnection *)connection{    //视频流一帧数据(UIImage类型)    UIImage * image =  [self imageFromSampleBuffer:sampleBuffer];        NSLog(@"视频流， 宽：(%f)  高：(%f)", image.size.width, image.size.height);    //IPHONE4  720  * 1280    //IPHONE5  1080 * 1920        //或：视频流一帧数据(NSData类型)    //NSData * imageData = http://www.mamicode.com/UIImageJPEGRepresentation(image, 0.5);>//Code...       }// Create a UIImage from sample buffer data- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer{    // Get a CMSampleBuffer‘s Core Video image buffer for the media data    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);    // Lock the base address of the pixel buffer    CVPixelBufferLockBaseAddress(imageBuffer, 0);        // Get the number of bytes per row for the pixel buffer    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);        // Get the number of bytes per row for the pixel buffer    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);    // Get the pixel buffer width and height    size_t width = CVPixelBufferGetWidth(imageBuffer);    size_t height = CVPixelBufferGetHeight(imageBuffer);        // Create a device-dependent RGB color space    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();        // Create a bitmap graphics context with the sample buffer data    CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,                                                 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);    // Create a Quartz image from the pixel data in the bitmap graphics context    CGImageRef quartzImage = CGBitmapContextCreateImage(context);    // Unlock the pixel buffer    CVPixelBufferUnlockBaseAddress(imageBuffer,0);        // Free up the context and color space    CGContextRelease(context);    CGColorSpaceRelease(colorSpace);        // Create an image object from the Quartz image    //UIImage *image = [UIImage imageWithCGImage:quartzImage];    UIImage *image = [UIImage imageWithCGImage:quartzImage scale:1.0f orientation:UIImageOrientationRight];        // Release the Quartz image    CGImageRelease(quartzImage);        return (image);}#pragma mark - 添加按钮 AND 点击按钮事件- (void)addCaptureButton{    CGRect frame = CGRectMake(0, 0, 100, 100);    UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];    btn.frame = frame;    [btn setTitle:@"拍照" forState:UIControlStateNormal];    btn.backgroundColor = [UIColor clearColor];    btn.tag = 1111;    [btn addTarget:self action:@selector(onClickCaptureButton:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];}-(IBAction)onClickCaptureButton:(id)sender{    [self takePicture];}#pragma mark - 保持图像到相册- (void)saveImageToPhotos:(UIImage*)savedImage{    UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);}// 指定回调方法- (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo{    NSString * msg = nil ;    if(error != NULL)    {        msg = @"保存图片失败" ;    }    else    {        msg = @"保存图片成功" ;    }        UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"保存图片结果提示"                                                    message:msg                                                   delegate:self                                          cancelButtonTitle:@"确定"                                          otherButtonTitles:nil];    [alert show];}#pragma mark - 拍照函数//拍照- (void) takePicture{    //1.    AVCaptureConnection * stillImageConnection = [self.stillImageOutput.connections objectAtIndex:0];        if ([stillImageConnection isVideoOrientationSupported]) {        [stillImageConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];    }        //2.    [self.stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {                        if (imageDataSampleBuffer != NULL)        {            //图像数据类型转换            NSData * imageData =http://www.mamicode.com/ [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];            UIImage * image = [[UIImage alloc] initWithData:imageData];                        //保存图像            [self saveImageToPhotos:image];                    }        else        {            NSLog(@"Error capturing still image %@", error);        }    }];    }@end