YUVConvert.cpp

//OpenCV Convert YUV buffer to rgb mat

Mat y(actual_size, CV_8UC1);
Mat u(half_size, CV_8UC1);
Mat v(half_size, CV_8UC1);
//
memcpy(y.data, frame_buffer->DataY(), actual_size.width * actual_size.height);
memcpy(u.data, frame_buffer->DataU(), half_size.width * half_size.height);
memcpy(v.data, frame_buffer->DataV(), half_size.width * half_size.height);
//
cv::Mat u_resized, v_resized;
cv::resize(u, u_resized, actual_size, 0, 0, cv::INTER_NEAREST); //repeat u values 4 times
cv::resize(v, v_resized, actual_size, 0, 0, cv::INTER_NEAREST); //repeat v values 4 times

cv::Mat yuv;
std::vector<cv::Mat> yuv_channels = { y, u_resized, v_resized };
cv::merge(yuv_channels, yuv);

cv::Mat bgr;
cv::cvtColor(yuv, bgr, cv::COLOR_YUV2BGR);


// YUV420/I420 Convert to nv12
void yuv420p_to_nv12(uint8_t* src, uint8_t* dst, int width, int height)
{
	memcpy(dst, src, height * width);
	int yBtyeSize = width * height;
	int unBtySize = width * height / 2;
	for (int i = 0; i < unBtySize / 2; i++) {
		dst[yBtyeSize + 2 * i] = src[yBtyeSize + i];
		dst[yBtyeSize + 2 * i + 1] = src[yBtyeSize + unBtySize / 2 + i];
	}
}

// NV12 Convert to YUV420
void nv12_to_yuv420(uint8_t* src, uint8_t* dst, int width, int height)
{
	memcpy(dst, src, height * width);
	int yBtyeSize = width * height;
	int unBtySize = width * height / 2;
	for (int i = 0; i < unBtySize / 2; i++) {
		src[yBtyeSize + i] = dst[yBtyeSize + 2 * i] ;
		src[yBtyeSize + unBtySize / 2 + i] = dst[yBtyeSize + 2 * i + 1] ;
	}
}

void splitYUV(uint8_t *yuvData, uint8_t* YData, uint8_t *UData, uint8_t *VData, int width, int height){
	memcpy(YData, yuvData, width * height);
	memcpy(UData, yuvData + width * height, width *height / 4);
	memcpy(VData, yuvData + width * height * 5 / 4, width * height / 4);
}