Capturing from webcam under WinPE? - c++

Question

I am writing a suite of hardware tests that will run in a windows PE environment. I need to test the webcam but so far I am stumped. I compiled a small webcam capture program using the opencv library, but it is unable to detect the webcam. I have tried loading additional drivers, but it hasn't worked. Unfortunately I have not found any help online since apparently no one else is crazy/stupid enough to attempt this. Is this idea fundamentally flawed in some way, or is there a way to do this? Any help is appreciated.
Here is the code I am using that compiles and runs on my windows 10 machine:
#include "opencv2/opencv.hpp"
#include <cstdio>
using namespace cv;
int main(int argc, char** argv)
{
VideoCapture cap;
// open the default camera, use something different from 0 otherwise;
// Check VideoCapture documentation.
if(!cap.isOpened()) // check if we succeeded
{
printf("Unable to open webcam");
return -1;
}
for(;;)
{
Mat frame;
cap >> frame;
if( frame.empty() ) break; // end of video stream
imshow("this is you, smile! :)", frame);
if( waitKey(10) == 27 ) break; // stop capturing by pressing ESC
}
// the camera will be closed automatically upon exit
// cap.close();
return 0;
}
Edit: I realized that the drivers were not loading on startup so I loaded them manually with drvload.exe. Now the webcam shows as functional when I do a WQL query(ConfigManagerErrorCode = 0) but my opencv program will still not detect it.

Answer 1

You won't get your cam to work, without adding some DLLs to your PE environment.
PE is a minimalistic WIndows that misses lots of functions due to minimize memory and diskspace consumption. It is only designed to offline edit Windows images, not to do hardware testing. Ran into similar issues some months ago.
I'm not sure if linking to this project is allowed here, but they sure have helpful information for you on that: TheOven