我们如何使用AVSampleBufferDisplayLayer来渲染CMSampleBufferRef？

#import <AVFoundation/AVFoundation.h>

AVSampleBufferDisplayLayer *displayLayer = [[AVSampleBufferDisplayLayer alloc] init];

displayLayer.frame = CGRectMake(0, 0, videoWidth, videoHeight);
displayLayer.position = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds));

[self.view.layer addSublayer:displayLayer];

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

// 配置输入
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
if ([captureSession canAddInput:videoInput]) {
    [captureSession addInput:videoInput];
}

// 配置输出
AVCaptureVideoDataOutput *videoOutput = [[AVCaptureVideoDataOutput alloc] init];
[videoOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
if ([captureSession canAddOutput:videoOutput]) {
    [captureSession addOutput:videoOutput];
}

// 启动会话
[captureSession startRunning];

- (void)captureOutput:(AVCaptureOutput *)output didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
    // 将sampleBuffer传递给displayLayer进行渲染
    [displayLayer enqueueSampleBuffer:sampleBuffer];
}