CODEWITHSUNDEEP
opencv
Sommerwild
Sommerwild

Reputation: 548

VideoCapture OpenCV 2.4.2 error in windows

I have a problem using VideoCapture class with OpenCV 2.4.2 under windows XP 32bits. It doesn't open any file or camera and fixing it's being a pain. Im using visual studio 2010 but i have also tried the code in QTcreator with the same result.

The testing code is the following: 

#include "opencv/cv.h"
#include "opencv/highgui.h"
#include <iostream>
#include <string> 
#include <iomanip> 
#include <sstream> 

using namespace cv;
using namespace std;

int main()
{
    const char* videoPath = "C:/video/";
    string videoName = string(videoPath) + "avi.avi";
    VideoCapture cap(videoName);

    if(!cap.isOpened()) 
    {
        std::cout<<"Fail"<<std::endl;
        return -3;
    }
    return 0; 
}

The output is always '-3'. Qt Creator shows a warning: Error opening file (../../modules/highgui/src/cap_ffmpeg_impl.hpp:361)

I debugged it and the problem appears in the first line of:

CvCapture* cvCreateFileCapture_FFMPEG_proxy(const char * filename)
{
    CvCapture_FFMPEG_proxy* result = new CvCapture_FFMPEG_proxy;
    if( result->open( filename ))
        return result;
    delete result;
#if defined WIN32 || defined _WIN32
    return cvCreateFileCapture_VFW(filename);
#else
    return 0;
#endif
}

in the cap_ffmpeg.cpp internal file.

I have tested the same code in a mac under snow leopard and it works. No surprises here since it must be a library issue. I have opened the avi file with the same path route using the c-function cvCapture easy and fast. I got all the dlls of 'C:\opencv\opencv\build\x86\vc10\bin' included in mi debug file. I got the tbb.dll and all the 'C:\opencv\opencv\3rdparty\ffmpeg' content included too.

This is drving me crazy so any help would be appreciated.

Thanks in advance.

Upvotes: 6

Views: 19611

Answers (5)

Ramineni Ravi Teja
Ramineni Ravi Teja

Reputation: 3906

I too faced the same issue and resolved after pointing to the correct location of the input video.

Upvotes: 0

prajod
prajod

Reputation: 505

See the fix I found below, for mp4 files. I faced the same issue on Windows 7, using OpenCV 2.4.9. I am using the java wrapper for opencv.

Matthias Krings has done a lot of research for this. See this. Apparently this is an issue based on the video file type. With .avi files, it seems to work for a lot of people. Unfortunately his solution of setting OPENCV_DIR did not work for me. But his comments in the bug listing gave me a hint to fix the issue.

You have to do two things:

  1. Set java.library.path to include the directory {opencv\install\dir}opencv-2.4.9\build\x86\vc10\bin. You can set the variable using the -D option on the java command line: java -Djava.library.path=PATH_TO_YOUR_DLL .... Also fetch this variable from your environment, using System.getProperty(...), and print it before calling loadLibrary(), to verify that the path setting is working.
  2. And in your java class, load the ffmpeg dll using System.loadLibrary("opencv_ffmpeg249");. The loadLibrary() function should be invoked from within a static block in java.
  3. There is a file named opencv_ffmpeg249.dll in the java.library.path that we set.
  4. This works on ubuntu also, for .so files.

Upvotes: 0

user2668043
user2668043

Reputation: 1

I had the same issue with the open method whilst running under Windows 8 (64bit), opencv 2.4.10. IDE is running in x86.

I found that running the application in release configuration solved the problem.

Stumbled across the answer because I had the same issue with imread. Issue is presented in the this thread. imread not working in Opencv

Upvotes: 0

Houqi
Houqi

Reputation: 31

I also faced with this problem and solved it by correct the path of the function:

VideoCapture cap(videoName);

If the AVI file of videoName does't exist, it will be an error:

(../../modules/highgui/src/cap_ffmpeg_impl.hpp:XXX)

where XXX represents the line number.

Upvotes: 3

Young-Shik Kwon
Young-Shik Kwon

Reputation: 56

In my case, the same problem was resolved after deleting all opencv_***.dll files in C:\Windows\System32. So, I use the dll files just through the path like "%PATH%;C: \Program Files \OpenCV2.4.2\build\x86\vc10/bin". Please try it.

Upvotes: 4

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