c - iOS开发中，如何从视频数据sampleBuffer中将数据转换成灰度图像数据？

Question

项目中用到了人脸识别，目前工作是需要从摄像头中拿数据传入到人脸算法中。
现在数据我通过AVFoundation中的代理方法拿到了原始数据sampleBuffer。

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

我如何从原始数据sampleBuffer中将数据转成算法能接收的灰度图像数据？

Answer 1

CVImageBufferRef imageBufferRef=CMSampleBufferGetImageBuffer(sampleBuffer);
    
CVPixelBufferLockBaseAddress(imageBufferRef, 0);
    
unsigned char *ptr_image=CVPixelBufferGetBaseAddressOfPlane(imageBufferRef, 0);
    
unsigned char* dst = (unsigned char *)malloc(sizeof(unsigned char) * 640 * 480 * 4);
    

Among them, 480 and 640 are the width and height of the incoming face recognition algorithm, which depends on the algorithm requirements

Answer 2

I also encountered this method, please give me some guidance.