AVFoundation 第一步,拿到我想要的数据

AVCaptureDevice

枚举说明部分

接下来是AVMediaType的枚举说明.未补充完整后续查阅资料来补齐.

还有一个摄像头的枚举部分.

摄像头的权限的枚举说明

思路 : 拿到摄像头->开启摄像头->捕捉画面->拿到数据 下面开始写代码

//
//  XJCaptureSesion.m
//  AVFoundation
//
//  Created by 张孝江 on 2021/4/1.
//

#import "XJCaptureManager.h"
#import <AVFoundation/AVFoundation.h>


@interface XJCaptureManager()<AVCaptureVideoDataOutputSampleBufferDelegate>
/**最主要的一个类**/
@property (nonatomic,strong) AVCaptureSession *session;
@property (nonatomic,strong) dispatch_queue_t sessionQueue;        //线程的队列

/*设备的抽象的类  输入*/
@property (nonatomic, strong) AVCaptureDeviceInput *frontCamera;
@property (nonatomic, strong) AVCaptureDeviceInput *backCamera;
@property (nonatomic, weak) AVCaptureDeviceInput   *currentCamera;
/**抽象类,  输出**/
@property (nonatomic,strong) AVCaptureVideoDataOutput *videoDataOutput;  // 这个是视频的输出的类.
@property (nonatomic, strong) AVCaptureConnection *videoConnection;
/**抽象类预览测**/
@property (nonatomic,strong) AVCaptureVideoPreviewLayer *preLayer;       //预览层

@end

@implementation XJCaptureManager

-(instancetype)init{
    if (self = [super init]) {
        [self initVideo];
    }
    return self;
}

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

#pragma mark - 开始捕捉..
-(void)initVideo{
    /**第一步获取摄像头**/
    AVCaptureDevice * front = [AVCaptureDevice defaultDeviceWithDeviceType:AVCaptureDeviceTypeBuiltInWideAngleCamera mediaType:AVMediaTypeVideo position:AVCaptureDevicePositionFront];
    self.frontCamera = [AVCaptureDeviceInput deviceInputWithDevice: front error:NULL];
    AVCaptureDevice *back = [AVCaptureDevice defaultDeviceWithDeviceType:AVCaptureDeviceTypeBuiltInWideAngleCamera mediaType:AVMediaTypeVideo position:AVCaptureDevicePositionBack];
    self.backCamera = [AVCaptureDeviceInput deviceInputWithDevice:back error:NULL];
    //设置默认选项为前置摄像头
    self.currentCamera = self.frontCamera;
    //设置视频的输出..
    [self.videoDataOutput setSampleBufferDelegate:self queue:self.sessionQueue];
    //会丢失处理不过来的帧数据.
    [self.videoDataOutput setAlwaysDiscardsLateVideoFrames:YES];
    //设置输出格式..
    NSDictionary *dictionary = @{
        (__bridge  NSString *)kCVPixelBufferPixelFormatTypeKey:@(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange)
    };
    //当你不知所错的时候 记得点开看一下
    /*
     On iOS, the only supported key is kCVPixelBufferPixelFormatTypeKey. Supported pixel formats are kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange, kCVPixelFormatType_420YpCbCr8BiPlanarFullRange and kCVPixelFormatType_32BGRA.
     */
    [self.videoDataOutput setVideoSettings:dictionary];
    //配置输入
    [self.session beginConfiguration];
    
    if ([self.session canAddInput:self.currentCamera]) {
        [self.session addInput:self.currentCamera];
    }
    //配置输出
    if ([self.session canAddOutput:self.videoDataOutput]) {
        [self.session addOutput:self.videoDataOutput];
    }
    //设置分辨率
    if ([self.session canSetSessionPreset:AVCaptureSessionPreset1920x1080]) {
        self.session.sessionPreset = AVCaptureSessionPreset1920x1080;
    }else if ([self.session canSetSessionPreset:AVCaptureSessionPreset1280x720]){
        self.session.sessionPreset = AVCaptureSessionPreset1280x720;
    }else if ([self.session canSetSessionPreset:AVCaptureSessionPreset640x480]){
        self.session.sessionPreset = AVCaptureSessionPreset640x480;
    }else{
        self.session.sessionPreset = AVCaptureSessionPreset352x288;
    }
    //结尾
    [self.session commitConfiguration];
    self.videoConnection  = [self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo];
    //设置视频的输出方向
    self.videoConnection.videoOrientation =  AVCaptureVideoOrientationPortrait;
    //设置分辨率..
    [self setUpdataFps:30];
    //设置预览层...
    [self.preview.layer addSublayer:self.preLayer];
}

#pragma mark - 根据代理取获取的文件的地址. 这就是当前获取的样本...
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
    NSLog(@"%@",sampleBuffer);
}




#pragma mark - 设置分辨率......
-(void)setUpdataFps:(NSInteger)fps{
    AVCaptureDevice *front = [AVCaptureDevice defaultDeviceWithDeviceType:AVCaptureDeviceTypeBuiltInWideAngleCamera mediaType:AVMediaTypeVideo position:AVCaptureDevicePositionFront];
    AVCaptureDevice *back = [AVCaptureDevice defaultDeviceWithDeviceType:AVCaptureDeviceTypeBuiltInWideAngleCamera mediaType:AVMediaTypeVideo position:AVCaptureDevicePositionBack];
    NSArray *array = @[front,back];
    
    for (AVCaptureDevice *device in array) {
        //获取当前支持的最大的FPS
        Float64 a = device.activeFormat.videoSupportedFrameRateRanges.firstObject.maxFrameRate;
        if (a >= fps) {
            if ([device lockForConfiguration:NULL]) {
                device.activeVideoMinFrameDuration = CMTimeMake(10, (int)(fps * 10));
                device.activeVideoMaxFrameDuration = device.activeVideoMinFrameDuration;
                [device unlockForConfiguration];
            }
        }
    }
}

-(void)dealloc{
    NSLog(@"我销毁了");
}



/*简单的初始化*/
-(AVCaptureSession *)session{
    if (!_session) {
        _session = [[AVCaptureSession alloc]init];
    }
    return _session;
}

/*初始化输出的类*/
-(AVCaptureVideoDataOutput *)videoDataOutput{
    if (!_videoDataOutput) {
        _videoDataOutput = [[AVCaptureVideoDataOutput alloc]init];
    }
    return _videoDataOutput;
}
-(dispatch_queue_t)sessionQueue{
    if (!_sessionQueue) {
        _sessionQueue = dispatch_queue_create("XJ.SESSION", NULL);
    }
    return _sessionQueue;
}

-(AVCaptureVideoPreviewLayer *)preLayer{
    if (!_preLayer) {
        _preLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
        _preLayer.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
        _preLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    }
    return _preLayer;
}
-(UIView *)preview{
    if (!_preview) {
        _preview = [[UIView alloc] init];
    }
    return _preview;
}


@end

在代理回调的地方就可以拿到这个视频的数据..