使用AVFoundation框架自定义摄像头界面

涉及到的类

需要遵循的协议

AVCaptureVideoDataOutputSampleBufferDelegate

初始化

//1.创建会话层
    self.session = [[[AVCaptureSession alloc] init] autorelease];
    [self.session setSessionPreset:AVCaptureSessionPresetPhoto];


    //2.创建、配置输入设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
#if 1
    int flags = NSKeyValueObservingOptionNew; //监听自动对焦
    [device addObserver:self forKeyPath:@"adjustingFocus" options:flags context:nil];
#endif

    NSError *error;
    AVCaptureDeviceInput *captureInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    if (!captureInput)
    {
        NSLog(@"Error: %@", error);
        return;
    }
    [self.session addInput:captureInput];


    //3.创建、配置输出       
    captureOutput = [[[AVCaptureStillImageOutput alloc] init] autorelease];
    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
    [captureOutput setOutputSettings:outputSettings];

    [outputSettings release];
    [self.session addOutput:captureOutput];

KVO回调

//对焦回调
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if( [keyPath isEqualToString:@"adjustingFocus"] ){
        BOOL adjustingFocus = [ [change objectForKey:NSKeyValueChangeNewKey] isEqualToNumber:[NSNumber numberWithInt:1] ];
        NSLog(@"Is adjusting focus? %@", adjustingFocus ? @"YES" : @"NO" );
        NSLog(@"Change dictionary: %@", change);
        if (delegate) {
            [delegate foucusStatus:adjustingFocus];
        }
    }
}

嵌入摄像头捕捉的界面

-(void) embedPreviewInView: (UIView *) aView {
    if (!session) return;
    //设置取景
    preview = [AVCaptureVideoPreviewLayer layerWithSession: session];
    preview.frame = aView.bounds;
    preview.videoGravity = AVLayerVideoGravityResizeAspectFill; 
    [aView.layer addSublayer: preview];
}

横竖屏适配

- (void)changePreviewOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    if (!preview) {
        return;
    }
     [CATransaction begin];
    if (interfaceOrientation == UIInterfaceOrientationLandscapeRight) {
        g_orientation = UIImageOrientationUp;
        preview.connection.videoOrientation = AVCaptureVideoOrientationLandscapeRight;

    }else if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft){
        g_orientation = UIImageOrientationDown;
        preview.connection.videoOrientation = AVCaptureVideoOrientationLandscapeLeft;

    }else if (interfaceOrientation == UIDeviceOrientationPortrait){
        g_orientation = UIImageOrientationRight;
        preview.connection.videoOrientation = AVCaptureVideoOrientationPortrait;

    }else if (interfaceOrientation == UIDeviceOrientationPortraitUpsideDown){
        g_orientation = UIImageOrientationLeft;
        preview.connection.videoOrientation = AVCaptureVideoOrientationPortraitUpsideDown;
    }
    [CATransaction commit];
}

- (void) startRunning
{
    [[self session] startRunning];    
}

- (void) stopRunning
{
    [[self session] stopRunning];
}

-(void)CaptureStillImage
{
    [self  Captureimage];
}

拍照

-(void)Captureimage
{
    //get connection
    AVCaptureConnection *videoConnection = nil;
    for (AVCaptureConnection *connection in captureOutput.connections) {
        for (AVCaptureInputPort *port in [connection inputPorts]) {
            if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
                videoConnection = connection;
                break;
            }
        }
        if (videoConnection) { break; }
    }

    //get UIImage
    [captureOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler:
     ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
         CFDictionaryRef exifAttachments =
         CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
         if (exifAttachments) {
             // Do something with the attachments.
         }

         // Continue as appropriate.
         NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
         UIImage *t_image = [UIImage imageWithData:imageData];   
         image = [[UIImage alloc]initWithCGImage:t_image.CGImage scale:1.0 orientation:g_orientation];

         [self giveImg2Delegate];
     }];
}

#pragma mark 切换前后摄像头
- (IBAction)toggleButtonClick:(UIButton *)sender {
    AVCaptureDevice *currentDevice=[self.captureDeviceInput device];
    AVCaptureDevicePosition currentPosition=[currentDevice position];
    [self removeNotificationFromCaptureDevice:currentDevice];
    AVCaptureDevice *toChangeDevice;
    AVCaptureDevicePosition toChangePosition=AVCaptureDevicePositionFront;
    if (currentPosition==AVCaptureDevicePositionUnspecified||currentPosition==AVCaptureDevicePositionFront) {
        toChangePosition=AVCaptureDevicePositionBack;
    }
    toChangeDevice=[self getCameraDeviceWithPosition:toChangePosition];
    [self addNotificationToCaptureDevice:toChangeDevice];
    //获得要调整的设备输入对象
    AVCaptureDeviceInput *toChangeDeviceInput=[[AVCaptureDeviceInput alloc]initWithDevice:toChangeDevice error:nil];

    //改变会话的配置前一定要先开启配置，配置完成后提交配置改变
    [self.captureSession beginConfiguration];
    //移除原有输入对象
    [self.captureSession removeInput:self.captureDeviceInput];
    //添加新的输入对象
    if ([self.captureSession canAddInput:toChangeDeviceInput]) {
        [self.captureSession addInput:toChangeDeviceInput];
        self.captureDeviceInput=toChangeDeviceInput;
    }
    //提交会话配置
    [self.captureSession commitConfiguration];

    [self setFlashModeButtonStatus];
}

#pragma mark 自动闪光灯开启
- (IBAction)flashAutoClick:(UIButton *)sender {
    [self setFlashMode:AVCaptureFlashModeAuto];
    [self setFlashModeButtonStatus];
}
#pragma mark 打开闪光灯
- (IBAction)flashOnClick:(UIButton *)sender {
    [self setFlashMode:AVCaptureFlashModeOn];
    [self setFlashModeButtonStatus];
}
#pragma mark 关闭闪光灯
- (IBAction)flashOffClick:(UIButton *)sender {
    [self setFlashMode:AVCaptureFlashModeOff];
    [self setFlashModeButtonStatus];
}

/**
 *  设置聚焦点
 *
 *  @param point 聚焦点
 */
-(void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point{
    [self changeDeviceProperty:^(AVCaptureDevice *captureDevice) {
        if ([captureDevice isFocusModeSupported:focusMode]) {
            [captureDevice setFocusMode:AVCaptureFocusModeAutoFocus];
        }
        if ([captureDevice isFocusPointOfInterestSupported]) {
            [captureDevice setFocusPointOfInterest:point];
        }
        if ([captureDevice isExposureModeSupported:exposureMode]) {
            [captureDevice setExposureMode:AVCaptureExposureModeAutoExpose];
        }
        if ([captureDevice isExposurePointOfInterestSupported]) {
            [captureDevice setExposurePointOfInterest:point];
        }
    }];
}

/**
 *  添加点按手势，点按时聚焦
 */
-(void)addGenstureRecognizer{
    UITapGestureRecognizer *tapGesture=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapScreen:)];
    [self.viewContainer addGestureRecognizer:tapGesture];
}
-(void)tapScreen:(UITapGestureRecognizer *)tapGesture{
    CGPoint point= [tapGesture locationInView:self.viewContainer];
    //将UI坐标转化为摄像头坐标
    CGPoint cameraPoint= [self.captureVideoPreviewLayer captureDevicePointOfInterestForPoint:point];
    [self setFocusCursorWithPoint:point];
    [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];
}

###本文代码
请查看此目录下面的 wx2 文件夹