Ip / network camera access.

edit

At first you must know the URL for snap (MJPEG) e.g. cvCaptureFromFile(http://ip_addr/snap.jpg); in C. The tail "/snap.jpg" is in Bosch Dinion Ip cameras. In my case it method only works (Linux, ffmpeg + h264 codecs installed), some cameras have problem with encoders and cooperative with installed codecs in system e.g. Bosch support as i saw only windows.

In one of my programs work this function, it's mixed C & C++ operators, in other way it won't work...

Mat GetImage(const char *CameraIP){

IplImage* IplImage;
CvCapture* capture;

capture = cvCaptureFromFile(CameraIP);
assert(capture);

IplImage = cvQueryFrame( capture );
assert(IplImage);
Mat OutImage(IplImage);
return( OutImage );

}

For live stream: 1)C: cvCaptureFromCAM(address); // open stream cvQueryFrame(CvCapture* capture); // get frame

2)C++ vcap.open(videoStreamAddress); // open stream vcap.read(image); // get frame

If you work on linux, and have tried a lot in other ways to resolve the problem, feel free to write about it.

I have read a lot of infos that for RTSP streaming from IP cameras are good framework POCO ([http://pocoproject.org/]).

Good luck

Hi,

I have one of the "malformed http header" ip cams (vilar IPC-1002), this code (in python) worked at first try, so one can switch it to other languages easily: http://stackoverflow.com/questions/21702477/how-to-parse-mjpeg-http-stream-from-ip-camera

The trick is to search for the start and stop of the jpeg image bypassing the http stuff.

Hope this help others. Pedro

I have found a work-around which is kind of hacky but it will probably work where other options have failed. It worked for me ;)

If you are able to open the stream with vlc (or other player/library) but fail to do it with opencv you can do this.

1 - Get vlc to open the http/rtsp stream from the ip camera.

2 - Set vlc to stream the source video to a file (Instructions here - http://www.ehow.com/how_11401801_stream-videos-internet-using-vlc.html).

You can probably do this step programmatically with a call to vlc executable with some parameters (Hint: you can run vlc without GUI by running cvlc).

3 - Use your preferred method of opening a file with opencv. I tested it this way (its standard video opening code):

int main(int, char**) {

    cv::VideoCapture vcap;
    cv::Mat image;
    const std::string video = "/path/video";

    if(!vcap.open(video)) {
        std::cout << "Error opening video stream or file" << std::endl;
        return -1;
    }

    for(;;) {
        if(!vcap.read(image)) {
            std::cout << "No frame" << std::endl;
            cv::waitKey();
        }
        cv::imshow("Output Window", image);
        if(cv::waitKey(1) >= 0) break;
    }   
}

Plus: this method could be improved if instead of redirecting the stream to a file, you could redirect to a device (/dev/something), and maybe opencv would be able to open it.

You can also read this stackoverflow post for more options: http://stackoverflow.com/a/7084081/1085483

You can use the following opencv c++ code for windows to get videostream from your IP WEBCAM app on android phone.

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main(int argc, char* argv[])
{
    VideoCapture cap; //

    cap.open("http://192.168.226.101:8080/video?x.mjpeg");
    if (!cap.isOpened())  // if not success, exit program
    {
        cout << "Cannot open the video cam" << endl;
        return -1;
    }

   double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get the width of frames of the video
   double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get the height of frames of the video

    cout << "Frame size : " << dWidth << " x " << dHeight << endl;

    namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"
    namedWindow("MyNegativeVideo",CV_WINDOW_AUTOSIZE);

    while (1)
    {
        Mat frame;
        Mat contours;

        bool bSuccess = cap.read(frame); // read a new frame from video

         if (!bSuccess) //if not success, break loop
        {
             cout << "Cannot read a frame from video stream" << endl;
             break;
        }

        flip(frame, frame, 1);
        imshow("MyVideo", frame); //show the frame in "MyVideo" window

        Canny(frame, contours, 500, 1000, 5, true);
        imshow("MyNegativeVideo", contours);

        if (waitKey(30) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
       {
            cout << "esc key is pressed by user" << endl;
            break;
       }
    }
    return 0;
}

Here, replace the ip address (192.168.226.101:8080) in

cap.open("http://192.168.226.101:8080/video?x.mjpeg");

with your ip address !! But make sure you have, ?x.mjpeg ,in the end (where x can be any string).

If this doesn't work then you should find out what your full ip address is? i.e. find out what is the string after the ip (In my case it was "/video" as shown in above address)