如何读取原始（YUV 4：2：2）格式图像数据来自内存

Question

I am trying to read the raw YUV 4:2:2 (720p) data from the Read buffer, I mapped the physical address of the Read buffer to the virtual address.

mem is a pointer which is pointing to Read buffer base address. I tried with below below-mentioned code but it is returning the empty image, please can anybody help me to read the Raw YUV 4:2:2 format image data from the memory.

I have tried below-mentioned code, but i is returning empty image

cv::Mat img(1,1280 , numCols,CV_8U1, mem);
//mem -> mem is a pointer to Read buffer which have raw YUV 4:2:2 image data .
//len-> Frame resolution (1280 * 720 * 3) (720p)
if (img.empty())
{
cout << "Image is not loaded" << endl;
return 0;
} 
cv::imshow("img",img);  
cv::waitKey();

Answer 1

The Raw YUV 4:2:2 image has a size = 2 * height * width. And You need to create:

cv::Mat img(2 * height, width, CV_8UC1, mem, sizeOfRowInBytes);

The Y channel will be in first height*sizeOfRowInBytes bytes. And after will be UV channels:

1. half of row with U and half with V;

2. half of row with U and half with V;

...

Height. half of row with U and half with V.