Converting YUV into BGR or RGB in OpenCV

In newer version of OPENCV there is a built in function can be used to do YUV to RGB conversion

cvtColor(src,dst,CV_YUV2BGR_YUY2);

specify the YUV format after the underscore, like this CV_YUYV2BGR_xxxx

It looks to me like you're decoding a YUV422 stream as YUV444. Try this modification to the code you provided:

for(int i = 0, j=0; i < 1280 * 720 * 3; i+=6, j+=4){    m_RGB->imageData[i] = pData[j] + pData[j+3]*((1 - 0.299)/0.615);    m_RGB->imageData[i+1] = pData[j] - pData[j+1]*((0.114*(1-0.114))/(0.436*0.587)) - pData[j+3]*((0.299*(1 - 0.299))/(0.615*0.587));    m_RGB->imageData[i+2] = pData[j] + pData[j+1]*((1 - 0.114)/0.436);    m_RGB->imageData[i+3] = pData[j+2] + pData[j+3]*((1 - 0.299)/0.615);    m_RGB->imageData[i+4] = pData[j+2] - pData[j+1]*((0.114*(1-0.114))/(0.436*0.587)) - pData[j+3]*((0.299*(1 - 0.299))/(0.615*0.587));    m_RGB->imageData[i+5] = pData[j+2] + pData[j+1]*((1 - 0.114)/0.436);}

I'm not sure you've got your constants correct, but at worst your colors will be off - the image should be recognizable.

I use the following C++ code using OpenCV to convert yuv data (YUV_NV21) to rgb image (BGR in OpenCV)

int main(){  const int width  = 1280;  const int height = 800;  std::ifstream file_in;  file_in.open("../image_yuv_nv21_1280_800_01.raw", std::ios::binary);  std::filebuf *p_filebuf = file_in.rdbuf();  size_t size = p_filebuf->pubseekoff(0, std::ios::end, std::ios::in);  p_filebuf->pubseekpos(0, std::ios::in);  char *buf_src = new char[size];  p_filebuf->sgetn(buf_src, size);  cv::Mat mat_src = cv::Mat(height*1.5, width, CV_8UC1, buf_src);  cv::Mat mat_dst = cv::Mat(height, width, CV_8UC3);  cv::cvtColor(mat_src, mat_dst, cv::COLOR_YUV2BGR_NV21);  cv::imwrite("yuv.png", mat_dst);  file_in.close();  delete []buf_src;  return 0;}

and the converted result is like the image yuv.png.

you can find the testing raw image from here and the whole project from my Github Project