Question

Could it be that there is a bug in OpenCV2.4 highgui for capturing frames from video in windows?

I installed both the precompiled libraries, the ones compiled by me, I can compile everything perfectly and I can run my programs if

they are image based. The problem is only for videos. OpenCV crashes in this function always:

 virtual IplImage* retrieveFrame(int)
    {
        unsigned char* data = 0;
        int step=0, width=0, height=0, cn=0;

        if(!ffmpegCapture ||
           !icvRetrieveFrame_FFMPEG_p(ffmpegCapture,&data,&step,&width,&height,&cn)) <-------CRASHES HERE
           return 0;
        cvInitImageHeader(&frame, cvSize(width, height), 8, cn);
        cvSetData(&frame, data, step);
        return &frame;
    }

This is inside the class cap_ffmpeg.cpp and is called by VideoCapture.

I tried versions 2.4.2 and 2.4.9. My programes were working finde with opencv2

---

More information

• Windows 7

• Build the projects with cmake (important as it could be that cmake is not building/finding the right codecs)

• VisualStudio 9 2008

• OpenCV 2.4.2

EDIT

It looks like it is actually a bug, so, how can I solve this problem and change my code to be able to read avi files?

Answer 1

As a temporary solution I decided to re-encode the videos so OpenCV doesn’t use the ffmpeg. I used VirtualDub with the microsoft video 1 compression, which uses “msvidc32.dll” driver.

It works with all my videos so it is enough by now as I can keep working with OpenCV in windows.