Windows MSMF not opening connected device

[feliwir]

System information (version)

• OpenCV => 3.4.1
• Operating System / Platform => Windows 64 Bit
• Compiler => Visual Studio 2017

Detailed description

Hello, i am trying to open my USB camera with MSMF (the camera is detected correctlyy by windows). The issue i am having is that vd_CaptureFormats is empty here: https://github.com/opencv/opencv/blob/3.4.1/modules/videoio/src/cap_msmf.cpp#L2311
However vd_CurrentFormats lists all supported formats.

Note that two USB cameras are connected at the same time.

Steps to reproduce

int main()
{
  int devices = 0;
  cv::VideoCapture cap;
  for (int i = 0; i < 5; ++i)
  {
    if (cap.open(CV_CAP_MSMF + i))
    {
      ++devices;
    }
  }
  cap.release();
}

[alalek]

In 3.4.1 list of formats is filtered by RGB24.

Try the latest code from 3.4 branch. MSMF backend has been refactored.

[feliwir]

@alalek
Hello thanks for the quick response. I‘d like to do that, but since we are using OpenCv in a production environment it’s not possible for me to use unstable version. Any ETA when there will be a new release with those changes?

[GregoryMorse]

Just to confirm, I am also experiencing the same issue that MSMF is not working for video capture in the latest 3.4.1 build.

[alalek]

Please try latest code from 3.4 branch. MSMF support has been significantly improved / refactored.
There is no plan to prepare separate fix for already released code from OpenCV 3.4.1.