1.OpenCV cvtColor CV_BGR2GRAY未声明的标识符的解决办法

加上这个引用即可

#include <opencv2\imgproc\types_c.h>

2.opencv里面CV_FOURCC找不到标识符

CV_FOURCC(‘M’,‘J’,‘P’,‘G’)–cv::VideoWriter::fourcc(‘M’,‘J’,‘P’,‘G’)

cv::VideoWriter writer("/home/nvidia/save_video/object_vedio2.avi",cv::VideoWriter::fourcc('M','J','P','G'),25,cv::Size(640,480));