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2018-08-25 08:10:05 -0600 received badge  Popular Question (source)
2015-06-05 09:20:57 -0600 commented question VideoWriter produces empty wmv

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

2015-06-04 18:24:14 -0600 asked a question VideoWriter produces empty wmv

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

Mat frame;
imshow("Stimulus Mode", frame);
if(m_recording && m_videoFile != NULL){

The code that opens the file is:

            m_videoFile = new VideoWriter(fname, CV_FOURCC('W', 'M', 'V', '2'), 25, Size(640, 480), true);
            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 = 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

2015-06-04 08:29:02 -0600 answered a question ACCESS MASK AMBIGUOUS SYMBOL

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.

2015-06-04 08:21:11 -0600 commented question ACCESS MASK AMBIGUOUS SYMBOL

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

2015-05-15 11:33:13 -0600 commented question cvCreateCameraCapture(0) crashes system

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.

2015-05-12 16:56:33 -0600 asked a question cvCreateCameraCapture(0) crashes system

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

2015-04-29 16:09:58 -0600 asked a question Some functions not available

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.

2015-04-16 10:10:11 -0600 commented question Trying to build OpenCV with Qt5.4 support

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)
2015-04-15 16:44:23 -0600 asked a question Trying to build OpenCV with Qt5.4 support

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?