快速开始采集和预览

一、音频采集

1.创建会话层

captureSession = [[AVCaptureSession alloc]init];

2.初始化音频采集设备

audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];

3.音频输入

NSError *error;
audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];

4.将音频输入添加到会话层

if([captureSession canAddInput:audioInput]){
        [captureSession addInput:audioInput];
}

5.音频输出

audioOutput = [[AVCaptureAudioDataOutput alloc]init];

6.音频输出代理

[audioOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];

7.将音频输出添加到会话层

if([captureSession canAddOutput:audioOutput]){
        [captureSession addOutput:audioOutput];
}

8.输出连接到媒体层

[audioOutput connectionWithMediaType:AVMediaTypeAudio];

9.开始采集

[captureSession startRunning];

二、视频采集

1.设置分辨率

captureSession.sessionPreset = AVCaptureSessionPresetMedium;

2.初始化视频采集设备

videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

3.视频输入

videoInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];

4.将视频输入添加到会话层

if([captureSession canAddInput:videoInput]){
        [captureSession addInput:videoInput];
}

5.视频输出

videoOutput =[[AVCaptureVideoDataOutput  alloc]init];

6.将视频输出添加到会话层

if([captureSession canAddOutput:videoOutput]){
        [captureSession addOutput:videoOutput];
}

7.视频数据处理队列

videoDataQueue = dispatch_queue_create("com.ksyun.queue",NULL);

8.视频输出代理

[videoOutput setSampleBufferDelegate:self queue:videoDataQueue]; 

9.预览layer

previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];
previewLayer.frame = self.view.frame;
[self.view.layer addSubLayer:previewLayer];

10.设置帧率

videoOutput.minFrameDuration = CMTime(1, 15);

11.开始采集

[captureSession startRunning];