// 捕獲音視頻

- (void)setupCaputureVideo

{

// 1.創建捕獲會話,必須要強引用，否則會被釋放

AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];

_captureSession = captureSession;

// 2.獲取攝像頭設備，默認是后置攝像頭

AVCaptureDevice *videoDevice = [self getVideoDevice:AVCaptureDevicePositionFront];

// 3.獲取聲音設備

AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];

// 4.創建對應視頻設備輸入對象

AVCaptureDeviceInput *videoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];

_currentVideoDeviceInput = videoDeviceInput;

// 5.創建對應音頻設備輸入對象

AVCaptureDeviceInput *audioDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:nil];

// 6.添加到會話中

// 注意“最好要判斷是否能添加輸入，會話不能添加空的

// 6.1 添加視頻

if ([captureSession canAddInput:videoDeviceInput]) {

[captureSession addInput:videoDeviceInput];

}

// 6.2 添加音頻

if ([captureSession canAddInput:audioDeviceInput]) {

[captureSession addInput:audioDeviceInput];

}

// 7.獲取視頻數據輸出設備

AVCaptureVideoDataOutput *videoOutput = [[AVCaptureVideoDataOutput alloc] init];

// 7.1 設置代理，捕獲視頻樣品數據

// 注意：隊列必須是串行隊列，才能獲取到數據，而且不能為空

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.獲取音頻數據輸出設備

AVCaptureAudioDataOutput *audioOutput = [[AVCaptureAudioDataOutput alloc] init];

// 8.2 設置代理，捕獲視頻樣品數據

// 注意：隊列必須是串行隊列，才能獲取到數據，而且不能為空

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.獲取視頻輸入與輸出連接，用于分辨音視頻數據

_videoConnection = [videoOutput connectionWithMediaType:AVMediaTypeVideo];

// 10.添加視頻預覽圖層

AVCaptureVideoPreviewLayer *previedLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];

previedLayer.frame = [UIScreen mainScreen].bounds;

[self.view.layer insertSublayer:previedLayer atIndex:0];

_previedLayer = previedLayer;

// 11.啟動會話

[captureSession startRunning];

}

// 指定攝像頭方向獲取攝像頭

- (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

// 獲取輸入設備數據，有可能是音頻有可能是視頻

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection

{

if (_videoConnection == connection) {

NSLog(@"采集到視頻數據");

} else {

NSLog(@"采集到音頻數據");

}

}