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asked 2018-06-11 06:32:11 -0600

azdoud.y gravatar image

How to solve problem with VideoCapture loading in linux ?

Hi,

I've written the following code so as to load a mp4 video into VideoCapture, however, when I check the capture with isOpened() I get false . I'm 100% sure that the mp4 file is within the folder but my code is not able to open the capture.

#include <iostream> // for standard I/O
#include <opencv2/core/core.hpp>        // Basic OpenCV structures (cv::Mat, Scalar)
#include <opencv2/imgproc/imgproc.hpp>  // Gaussian Blur
#include <opencv2/highgui/highgui.hpp>  // OpenCV window I/O
#include <thread>
#include <future>

using namespace std;
using namespace cv;

int loadVideo( VideoCapture cap1, int seek_step,int thrd){
    int frameNum = 0;
    Mat frame;
     char c;
    cap1.set(CV_CAP_PROP_POS_FRAMES, seek_step );
    while (1){
        cap1 >> frame;
        if (frame.empty())
        {
            cout << " < < <  Channel stream ended!  > > > ";
            break;
        }

        cout << frameNum << endl;
        ++frameNum;
    }
    return frameNum;
}

int main(int argc, char *argv[])
{
    string sourceVideoPath;
    sourceVideoPath = "/home/azdoud/case1_320_200/case320_200fps20.mp4";
//    sourceVideoPath = "case320_240fps20.mp4";
//    sourceVideoPath = "C:\\opencvVid\\case1_320_240\\vid320_240fps25.mp4";
//    sourceVideoPath = argv[1];
    //start a new VideoCapture object in each of your 4 threads
    VideoCapture cap1(sourceVideoPath);

    cout << "Stream frame numbre : " << cap1.get(CV_CAP_PROP_FRAME_COUNT)<<endl;
    if (!cap1.isOpened())
    {
        cout  << "Could not open video " << sourceVideoPath << endl;
        return -1;
    }

    loadVideo(cap1,0,1);

    return 0;
}

I've put the video in the same folder but no good results.

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Stream frame numbre : 0
Could not open video case320_240fps20.mp4

thank you in advance.

How to solve problem with VideoCapture loading in linux ?

Hi,

I've written the following code so as to load a mp4 video into VideoCapture, however, when I check the capture with isOpened() I get false . I'm 100% sure that the mp4 file is within the folder but my code is not able to open the capture.

#include <iostream> // for standard I/O
#include <opencv2/core/core.hpp>        // Basic OpenCV structures (cv::Mat, Scalar)
#include <opencv2/imgproc/imgproc.hpp>  // Gaussian Blur
#include <opencv2/highgui/highgui.hpp>  // OpenCV window I/O
#include <thread>
#include <future>

using namespace std;
using namespace cv;

int loadVideo( VideoCapture cap1, int seek_step,int thrd){
    int frameNum = 0;
    Mat frame;
     char c;
    cap1.set(CV_CAP_PROP_POS_FRAMES, seek_step );
    while (1){
        cap1 >> frame;
        if (frame.empty())
        {
            cout << " < < <  Channel stream ended!  > > > ";
            break;
        }

        cout << frameNum << endl;
        ++frameNum;
    }
    return frameNum;
}

int main(int argc, char *argv[])
{
    string sourceVideoPath;
    sourceVideoPath = "/home/azdoud/case1_320_200/case320_200fps20.mp4";
//    sourceVideoPath = "case320_240fps20.mp4";
//    sourceVideoPath = "C:\\opencvVid\\case1_320_240\\vid320_240fps25.mp4";
//    sourceVideoPath = argv[1];
    //start a new VideoCapture object in each of your 4 threads
    VideoCapture cap1(sourceVideoPath);

    cout << "Stream frame numbre : " << cap1.get(CV_CAP_PROP_FRAME_COUNT)<<endl;
    if (!cap1.isOpened())
    {
        cout  << "Could not open video " << sourceVideoPath << endl;
        return -1;
    }

    loadVideo(cap1,0,1);

    return 0;
}

I've put the video in the same folder but no good results.

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Stream frame numbre : 0
Could not open video case320_240fps20.mp4

in I tested this code it works well, the image is in the same folder too 

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
using namespace std;
using namespace cv;

int main()
{
    Mat src;

    /// Load image
    src = imread(  "/home/azdoud/im.jpg");
//    src = imread( "C:\\opencvVid\\images\\1.png" );
    cout << "Width : " << src.size().width << endl;
    cout << "Height: " << src.size().height << endl;
    return 0;
}

thank you in advance.

How to solve problem with VideoCapture loading in linux ?

Hi,

I've written the following code so as to load a mp4 video into VideoCapture, however, when I check the capture with isOpened() I get false . I'm 100% sure that the mp4 file is within the folder but my code is not able to open the capture.

#include <iostream> // for standard I/O
#include <opencv2/core/core.hpp>        // Basic OpenCV structures (cv::Mat, Scalar)
#include <opencv2/imgproc/imgproc.hpp>  // Gaussian Blur
#include <opencv2/highgui/highgui.hpp>  // OpenCV window I/O
#include <thread>
#include <future>

using namespace std;
using namespace cv;

int loadVideo( VideoCapture cap1, int seek_step,int thrd){
    int frameNum = 0;
    Mat frame;
     char c;
    cap1.set(CV_CAP_PROP_POS_FRAMES, seek_step );
    while (1){
        cap1 >> frame;
        if (frame.empty())
        {
            cout << " < < <  Channel stream ended!  > > > ";
            break;
        }

        cout << frameNum << endl;
        ++frameNum;
    }
    return frameNum;
}

int main(int argc, char *argv[])
{
    string sourceVideoPath;
    sourceVideoPath = "/home/azdoud/case1_320_200/case320_200fps20.mp4";
//    sourceVideoPath = "case320_240fps20.mp4";
//    sourceVideoPath = "C:\\opencvVid\\case1_320_240\\vid320_240fps25.mp4";
//    sourceVideoPath = argv[1];
    //start a new VideoCapture object in each of your 4 threads
    VideoCapture cap1(sourceVideoPath);

    cout << "Stream frame numbre : " << cap1.get(CV_CAP_PROP_FRAME_COUNT)<<endl;
    if (!cap1.isOpened())
    {
        cout  << "Could not open video " << sourceVideoPath << endl;
        return -1;
    }

    loadVideo(cap1,0,1);

    return 0;
}

I've put the video in the same folder but no good results.

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Stream frame numbre : 0
Could not open video case320_240fps20.mp4

in I tested this code it works well, the image is in the same folder too 

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
using namespace std;
using namespace cv;

int main()
{
    Mat src;

    /// Load image
    src = imread(  "/home/azdoud/im.jpg");
//    src = imread( "C:\\opencvVid\\images\\1.png" );
    cout << "Width : " << src.size().width << endl;
    cout << "Height: " << src.size().height << endl;
    return 0;
}

this the result 

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Width : 0
Height: 0

you may tell is a probelm of permission, I've checked that too by setting chmod to 666 on the folder and on mp4 file. How can you explain this, I can't understand why

any help thank you in advance.

How to solve problem with VideoCapture loading in linux ?

Hi,

I've written the following code so as to load a mp4 video into VideoCapture, however, when I check the capture with isOpened() I get false . I'm 100% sure that the mp4 file is within the folder but my code is not able to open the capture.

#include <iostream> // for standard I/O
#include <opencv2/core/core.hpp>        // Basic OpenCV structures (cv::Mat, Scalar)
#include <opencv2/imgproc/imgproc.hpp>  // Gaussian Blur
#include <opencv2/highgui/highgui.hpp>  // OpenCV window I/O
#include <thread>
#include <future>

using namespace std;
using namespace cv;

int loadVideo( VideoCapture cap1, int seek_step,int thrd){
    int frameNum = 0;
    Mat frame;
     char c;
    cap1.set(CV_CAP_PROP_POS_FRAMES, seek_step );
    while (1){
        cap1 >> frame;
        if (frame.empty())
        {
            cout << " < < <  Channel stream ended!  > > > ";
            break;
        }

        cout << frameNum << endl;
        ++frameNum;
    }
    return frameNum;
}

int main(int argc, char *argv[])
{
    string sourceVideoPath;
    sourceVideoPath = "/home/azdoud/case1_320_200/case320_200fps20.mp4";
//    sourceVideoPath = "case320_240fps20.mp4";
//    sourceVideoPath = "C:\\opencvVid\\case1_320_240\\vid320_240fps25.mp4";
//    sourceVideoPath = argv[1];
    //start a new VideoCapture object in each of your 4 threads
    VideoCapture cap1(sourceVideoPath);

    cout << "Stream frame numbre : " << cap1.get(CV_CAP_PROP_FRAME_COUNT)<<endl;
    if (!cap1.isOpened())
    {
        cout  << "Could not open video " << sourceVideoPath << endl;
        return -1;
    }

    loadVideo(cap1,0,1);

    return 0;
}

I've put the video in the same folder but no good results.

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Stream frame numbre : 0
Could not open video case320_240fps20.mp4

in I tested this code it works well, the image is in the same folder too 

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
using namespace std;
using namespace cv;

int main()
{
    Mat src;

    /// Load image
    src = imread(  "/home/azdoud/im.jpg");
//    src = imread( "C:\\opencvVid\\images\\1.png" );
    cout << "Width : " << src.size().width << endl;
    cout << "Height: " << src.size().height << endl;
    return 0;
}

this the result 

[azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/azdoud/CentOSsimple
[azdoud@video-processor CentOSsimple]$ make
Scanning dependencies of target main
[100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
Linking CXX executable main
[100%] Built target main
[azdoud@video-processor CentOSsimple]$ ./main
Width : 0
Height: 0

you may tell is a probelm of permission, I've checked that too by setting chmod to 666 on the folder and on mp4 file. How can you explain this, I can't understand why

any help thank you in advance.

here the getBuildInformation() output

 [azdoud@video-processor CentOSsimple]$ cmake -DCMAKE_CXX_FLAGS="-std=c++11"
 -- Configuring done
 -- Generating done
 -- Build files have been written to: /home/azdoud/CentOSsimple
 [azdoud@video-processor CentOSsimple]$ make
 Scanning dependencies of target main
 [100%] Building CXX object CMakeFiles/main.dir/main.cpp.o
 Linking CXX executable main
 [100%] Built target main
 [azdoud@video-processor CentOSsimple]$ ./main
 Built info
 General configuration for OpenCV 2.4.8.2 =====================================
   Version control:               2.4.8.2

   Platform:
     Host:                        Linux 3.10.0-693.21.1.el7.x86_64 x86_64
     CMake:                       2.8.12.2
     CMake generator:             Unix Makefiles
     CMake build tool:            /bin/gmake
     Configuration:               RELEASE

   C/C++:
     Built as dynamic libs?:      YES
     C++ Compiler:                /bin/c++  (ver 4.8.5)
     C++ flags (Release):         -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections   -DNDEBUG
     C++ flags (Debug):           -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections   -O0 -DDEBUG -D_DEBUG
     C Compiler:                  /bin/cc
     C flags (Release):           -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -O3 -DNDEBUG  -DNDEBUG
     C flags (Debug):             -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -g  -O0 -DDEBUG -D_DEBUG
     Linker flags (Release):
     Linker flags (Debug):
     Precompiled headers:         YES

   OpenCV modules:
     To be built:                 core flann imgproc highgui features2d calib3d ml video legacy objdetect photo gpu ocl nonfree contrib stitching superres ts videostab
     Disabled:                    world
     Disabled by dependency:      -
     Unavailable:                 androidcamera dynamicuda java python

   GUI:
     QT:                          NO
     GTK+ 2.x:                    YES (ver 2.24.31)
     GThread :                    YES (ver 2.54.2)
     GtkGlExt:                    NO
     OpenGL support:              NO

   Media I/O:
     ZLib:                        /lib64/libz.so (ver 1.2.7)
     JPEG:                        libjpeg (ver 62)
     PNG:                         /lib64/libpng.so (ver 1.5.13)
     TIFF:                        build (ver 42 - 4.0.2)
     JPEG 2000:                   build (ver 1.900.1)
     OpenEXR:                     build (ver 1.7.1)

   Video I/O:
     DC1394 1.x:                  NO
     DC1394 2.x:                  NO
     FFMPEG:                      NO
       codec:                     NO
       format:                    NO
       util:                      NO
       swscale:                   NO
       gentoo-style:              NO
     GStreamer:                   NO
     OpenNI:                      NO
     OpenNI PrimeSensor Modules:  NO
     PvAPI:                       NO
     GigEVisionSDK:               NO
     UniCap:                      NO
     UniCap ucil:                 NO
     V4L/V4L2:                    NO/YES
     XIMEA:                       NO
     Xine:                        NO

   Other third-party libraries:
     Use IPP:                     NO
     Use Eigen:                   NO
     Use TBB:                     NO
     Use OpenMP:                  NO
     Use GCD                      NO
     Use Concurrency              NO
     Use C=:                      NO
     Use Cuda:                    NO
     Use OpenCL:                  YES

   OpenCL:
     Version:                     dynamic
     Include path:                /opt/working/opencv/3rdparty/include/opencl/1.2
     Use AMD FFT:                 NO
     Use AMD BLAS:                NO

   Python:
     Interpreter:                 /bin/python2 (ver 2.7.5)

   Java:
     ant:                         NO
     JNI:                         NO
     Java tests:                  NO

   Documentation:
     Build Documentation:         NO
     Sphinx:                      NO
     PdfLaTeX compiler:           NO

   Tests and samples:
     Tests:                       YES
     Performance tests:           YES
     C/C++ Examples:              NO

   Install path:                  /usr/local

   cvconfig.h is in:              /opt/working/opencv/release
 -----------------------------------------------------------------


 Stream frame numbre : 0
 Could not open video case320_240fps20.mp4
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