opencv4 Identifier not defined in CV_CAP_PROP_FPS;CV_CAP_PROP_FRAME_COUNT;CV_CAP_PROP_POS_FRAMES problem

The problem this time is to read a video , But in the process of writing code, there is a problem of undefined representation , The error results are as follows ：、

After many inquiries , The discovery is due to opencv Version update too fast ,opencv4 Many identifiers have changed in , Make the following changes to the following three identifiers ：

CV_CAP_PROP_FPS   ->    CAP_PROP_FPS
CV_CAP_PROP_FRAME_COUNT ->  CAP_PROP_FRAME_COUNT
CV_CAP_PROP_POS_FRAMES ->  CAP_PROP_POS_FRAMES

And if there's no Definition cv The namespace of Words （using namespace cv;） It is necessary to use cv::CAP_PROP_FRAME_COUNT, In this way, you won't make a mistake .

Record all the problems encountered here , Prevent yourself from forgetting , I hope it will be helpful to you