// 捕获音视频
- (void)setupCaputureVideo
{// 1.创建捕获会话,必须要强引用，否则会被释放AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];_captureSession = captureSession;// 2.获取摄像头设备，默认是后置摄像头AVCaptureDevice *videoDevice = [self getVideoDevice:AVCaptureDevicePositionFront];// 3.获取声音设备AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];// 4.创建对应视频设备输入对象AVCaptureDeviceInput *videoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];_currentVideoDeviceInput = videoDeviceInput;// 5.创建对应音频设备输入对象AVCaptureDeviceInput *audioDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:nil];// 6.添加到会话中// 注意“最好要判断是否能添加输入，会话不能添加空的// 6.1 添加视频if ([captureSession canAddInput:videoDeviceInput]) {[captureSession addInput:videoDeviceInput];}// 6.2 添加音频if ([captureSession canAddInput:audioDeviceInput]) {[captureSession addInput:audioDeviceInput];}// 7.获取视频数据输出设备AVCaptureVideoDataOutput *videoOutput = [[AVCaptureVideoDataOutput alloc] init];// 7.1 设置代理，捕获视频样品数据// 注意：队列必须是串行队列，才能获取到数据，而且不能为空dispatch_queue_t videoQueue = dispatch_queue_create("Video Capture Queue", DISPATCH_QUEUE_SERIAL);[videoOutput setSampleBufferDelegate:self queue:videoQueue];if ([captureSession canAddOutput:videoOutput]) {[captureSession addOutput:videoOutput];}// 8.获取音频数据输出设备AVCaptureAudioDataOutput *audioOutput = [[AVCaptureAudioDataOutput alloc] init];// 8.2 设置代理，捕获视频样品数据// 注意：队列必须是串行队列，才能获取到数据，而且不能为空dispatch_queue_t audioQueue = dispatch_queue_create("Audio Capture Queue", DISPATCH_QUEUE_SERIAL);[audioOutput setSampleBufferDelegate:self queue:audioQueue];if ([captureSession canAddOutput:audioOutput]) {[captureSession addOutput:audioOutput];}// 9.获取视频输入与输出连接，用于分辨音视频数据_videoConnection = [videoOutput connectionWithMediaType:AVMediaTypeVideo];// 10.添加视频预览图层AVCaptureVideoPreviewLayer *previedLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];previedLayer.frame = [UIScreen mainScreen].bounds;[self.view.layer insertSublayer:previedLayer atIndex:0];_previedLayer = previedLayer;// 11.启动会话
    [captureSession startRunning];
}// 指定摄像头方向获取摄像头
- (AVCaptureDevice *)getVideoDevice:(AVCaptureDevicePosition)position
{NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];for (AVCaptureDevice *device in devices) {if (device.position == position) {return device;}}return nil;
}#pragma mark - AVCaptureVideoDataOutputSampleBufferDelegate
// 获取输入设备数据，有可能是音频有可能是视频
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{if (_videoConnection == connection) {NSLog(@"采集到视频数据");} else {NSLog(@"采集到音频数据");}
}

// 切换摄像头
- (IBAction)toggleCapture:(id)sender {// 获取当前设备方向AVCaptureDevicePosition curPosition = _currentVideoDeviceInput.device.position;// 获取需要改变的方向AVCaptureDevicePosition togglePosition = curPosition == AVCaptureDevicePositionFront?AVCaptureDevicePositionBack:AVCaptureDevicePositionFront;// 获取改变的摄像头设备AVCaptureDevice *toggleDevice = [self getVideoDevice:togglePosition];// 获取改变的摄像头输入设备AVCaptureDeviceInput *toggleDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:toggleDevice error:nil];// 移除之前摄像头输入设备
    [_captureSession removeInput:_currentVideoDeviceInput];// 添加新的摄像头输入设备
    [_captureSession addInput:toggleDeviceInput];// 记录当前摄像头输入设备_currentVideoDeviceInput = toggleDeviceInput;}

// 点击屏幕，出现聚焦视图
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{// 获取点击位置UITouch *touch = [touches anyObject];CGPoint point = [touch locationInView:self.view];// 把当前位置转换为摄像头点上的位置CGPoint cameraPoint = [_previedLayer captureDevicePointOfInterestForPoint:point];// 设置聚焦点光标位置
    [self setFocusCursorWithPoint:point];// 设置聚焦
    [self focusWithMode:AVCaptureFocusModeAutoFocus exposureMode:AVCaptureExposureModeAutoExpose atPoint:cameraPoint];
}/***  设置聚焦光标位置**  @param point 光标位置*/
-(void)setFocusCursorWithPoint:(CGPoint)point{self.focusCursorImageView.center=point;self.focusCursorImageView.transform=CGAffineTransformMakeScale(1.5, 1.5);self.focusCursorImageView.alpha=1.0;[UIView animateWithDuration:1.0 animations:^{self.focusCursorImageView.transform=CGAffineTransformIdentity;} completion:^(BOOL finished) {self.focusCursorImageView.alpha=0;}];
}/***  设置聚焦*/
-(void)focusWithMode:(AVCaptureFocusMode)focusMode exposureMode:(AVCaptureExposureMode)exposureMode atPoint:(CGPoint)point{AVCaptureDevice *captureDevice = _currentVideoDeviceInput.device;// 锁定配置
    [captureDevice lockForConfiguration:nil];// 设置聚焦if ([captureDevice isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {[captureDevice setFocusMode:AVCaptureFocusModeAutoFocus];}if ([captureDevice isFocusPointOfInterestSupported]) {[captureDevice setFocusPointOfInterest:point];}// 设置曝光if ([captureDevice isExposureModeSupported:AVCaptureExposureModeAutoExpose]) {[captureDevice setExposureMode:AVCaptureExposureModeAutoExpose];}if ([captureDevice isExposurePointOfInterestSupported]) {[captureDevice setExposurePointOfInterest:point];}// 解锁配置
    [captureDevice unlockForConfiguration];
}