bear35645's profile - activity

pklab, you can promote your comment as the answer. It turned out to be the image size.

I am attempting to write to a wmv file, but the following code produces a empty file.

Mat frame;
m_cam->read(frame);
imshow("Stimulus Mode", frame);
if(m_recording && m_videoFile != NULL){
    m_videoFile->write(frame);
}

The code that opens the file is:

            m_videoFile = new VideoWriter(fname, CV_FOURCC('W', 'M', 'V', '2'), 25, Size(640, 480), true);
        if(!m_videoFile->isOpened()){
            m_videoFile->open(fname, CV_FOURCC('W', 'M', 'V', '2'), 25, Size(640, 480), true);
        }

Then when I close it here:

    if(m_videoFile != NULL){
       m_videoFile->release();
       m_videoFile = NULL;\
    }

I am using openCV3.0 on Windows 32 bit and using MSVC2013 compiler.

imShow is displaying the video as I am expecting.

Thanks in advance, Bear

I found the answer some place else. The problem is caused by putting "using namespace cv;" in a header. If you need to define a class member that is part of the cv namespace in the header, use cv:: in front of the class name and move the using namespace to your cpp file.

I am getting the same error. Did you resolve this?

The reason for the vagueness is simple. As soon as cvCreateCameraCapture(0) is executed, the screen turns black and the only way out is a hard boot.

This much I have been able to track down. The camera is actually similar to a Camcorder, and the feed is composite video. Maybe I need to rebuild the OpenCV libraries with some other modules? I don't know.

We did install a piece of software on the device that took the composite video and someone made it look like a Webcam feed. However, now cvCreateCameraCapture returns a NULL. I tried a for loop and looping from 0 to 4, but that didn't work either. Even if this worked, it would be less than a perfect solution.

Swapping cameras is not an option. The code needs to work with the camera on the system that work.

I had this program working and all of a sudden now when my program gets to cvCreateCameraCapture(0) it crashes the whole system. I have tried changing the 0 to -1 with the same result.

I did build the libraries on the system I am with the issue. The system is a 32 bit system runningWindows 7 Embedded. I am using Qt as my IDE and Mingw32 compiler. The libraries were compiled with MingW as well.

In debug mode I can see that it loads a lot of DLLs, the starts some threads before crashing. I believe 3 threads get started and maybe is attempting to start a 4th.

This same code does run fine on another system but the camera is different.

Anyone have an idea?

Thanks in advance, Kevin

I have built OpenCV with QT support with MingW32. There are a couple functions I am trying to use, but they don't seem to be declared. One is putText the other is getTextSize. At the beginning of my source code I have "using namespace cv;"

I am at a loss as to why these functions are not declared with other OpenCV functions are.

If I remove the path to qmake I receive the following:

 Found unsuitable Qt version "" from NOTFOUND, this code requires Qt 4.x
Call Stack (most recent call first):
  cmake/OpenCVFindLibsGUI.cmake:34 (find_package)
  CMakeLists.txt:505 (include)

When I attempt to configure CMake through the gui, I get the following error:

    C:/Qt/5.4/mingw491_32/bin/qmake.exe, this code requires Qt 4.x
Call Stack (most recent call first):
  cmake/OpenCVFindLibsGUI.cmake:34 (find_package)
  CMakeLists.txt:505 (include)

What am I doing wrong. How can I make it realize I have Qt 5.4 installed?