Multiple streaming in c++ using opencv; OpenCV video streaming over TCP/IP

client.cpp

/**
 * OpenCV video streaming over TCP/IP
 * Client: Receives video from server and display it
 * by Steve Tuenkam
 */

#include "opencv2/opencv.hpp"
#include <sys/socket.h> 
#include <arpa/inet.h>
#include <unistd.h>

using namespace cv;


int main(int argc, char** argv)
{

    //--------------------------------------------------------
    //networking stuff: socket , connect
    //--------------------------------------------------------
    int         sokt;
    char*       serverIP;
    int         serverPort;

    if (argc < 3) {
           std::cerr << "Usage: cv_video_cli <serverIP> <serverPort> " << std::endl;
    }

    serverIP   = argv[1];
    serverPort = atoi(argv[2]);

    struct  sockaddr_in serverAddr;
    socklen_t           addrLen = sizeof(struct sockaddr_in);

    if ((sokt = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
        std::cerr << "socket() failed" << std::endl;
    }

    serverAddr.sin_family = PF_INET;
    serverAddr.sin_addr.s_addr = inet_addr(serverIP);
    serverAddr.sin_port = htons(serverPort);

    if (connect(sokt, (sockaddr*)&serverAddr, addrLen) < 0) {
        std::cerr << "connect() failed!" << std::endl;
    }



    //----------------------------------------------------------
    //OpenCV Code
    //----------------------------------------------------------

    Mat img;
    img = Mat::zeros(480 , 640, CV_8UC1);    
    int imgSize = img.total() * img.elemSize();
    uchar *iptr = img.data;
    int bytes = 0;
    int key;

    //make img continuos
    if ( ! img.isContinuous() ) { 
          img = img.clone();
    }
        
    std::cout << "Image Size:" << imgSize << std::endl;


    namedWindow("CV Video Client",1);

    while (key != 'q') {

        if ((bytes = recv(sokt, iptr, imgSize , MSG_WAITALL)) == -1) {
            std::cerr << "recv failed, received bytes = " << bytes << std::endl;
        }
        
        cv::imshow("CV Video Client", img); 
      
        if (key = cv::waitKey(10) >= 0) break;
    }   

    close(sokt);

    return 0;
}	

serveur.cpp

/**
 * OpenCV video streaming over TCP/IP
 * Server: Captures video from a webcam and send it to a client
 * by Isaac Maia
 */

#include "opencv2/opencv.hpp"
#include <iostream>
#include <sys/socket.h> 
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <unistd.h> 
#include <string.h>

using namespace cv;

void *display(void *);

int capDev = 0;

    VideoCapture cap(capDev); // open the default camera
    

   


int main(int argc, char** argv)
{   

    //--------------------------------------------------------
    //networking stuff: socket, bind, listen
    //--------------------------------------------------------
    int                 localSocket,
                        remoteSocket,
                        port = 4097;                               

    struct  sockaddr_in localAddr,
                        remoteAddr;
    pthread_t thread_id;
    
           
    int addrLen = sizeof(struct sockaddr_in);

       
    if ( (argc > 1) && (strcmp(argv[1],"-h") == 0) ) {
          std::cerr << "usage: ./cv_video_srv [port] [capture device]\n" <<
                       "port           : socket port (4097 default)\n" <<
                       "capture device : (0 default)\n" << std::endl;

          exit(1);
    }

    if (argc == 2) port = atoi(argv[1]);

    localSocket = socket(AF_INET , SOCK_STREAM , 0);
    if (localSocket == -1){
         perror("socket() call failed!!");
    }    

    localAddr.sin_family = AF_INET;
    localAddr.sin_addr.s_addr = INADDR_ANY;
    localAddr.sin_port = htons( port );

    if( bind(localSocket,(struct sockaddr *)&localAddr , sizeof(localAddr)) < 0) {
         perror("Can't bind() socket");
         exit(1);
    }
    
    //Listening
    listen(localSocket , 3);
    
    std::cout <<  "Waiting for connections...\n"
              <<  "Server Port:" << port << std::endl;

    //accept connection from an incoming client
    while(1){
    //if (remoteSocket < 0) {
    //    perror("accept failed!");
    //    exit(1);
    //}
       
     remoteSocket = accept(localSocket, (struct sockaddr *)&remoteAddr, (socklen_t*)&addrLen);  
      //std::cout << remoteSocket<< "32"<< std::endl;
    if (remoteSocket < 0) {
        perror("accept failed!");
        exit(1);
    } 
    std::cout << "Connection accepted" << std::endl;
     pthread_create(&thread_id,NULL,display,&remoteSocket);

     //pthread_join(thread_id,NULL);

    }
    //pthread_join(thread_id,NULL);
    //close(remoteSocket);

    return 0;
}

void *display(void *ptr){
    int socket = *(int *)ptr;
    //OpenCV Code
    //----------------------------------------------------------

    Mat img, imgGray;
    img = Mat::zeros(480 , 640, CV_8UC1);   
     //make it continuous
    if (!img.isContinuous()) {
        img = img.clone();
    }

    int imgSize = img.total() * img.elemSize();
    int bytes = 0;
    int key;
    

    //make img continuos
    if ( ! img.isContinuous() ) { 
          img = img.clone();
          imgGray = img.clone();
    }
        
    std::cout << "Image Size:" << imgSize << std::endl;

    while(1) {
                
            /* get a frame from camera */
                cap >> img;
            
                //do video processing here 
                cvtColor(img, imgGray, CV_BGR2GRAY);

                //send processed image
                if ((bytes = send(socket, imgGray.data, imgSize, 0)) < 0){
                     std::cerr << "bytes = " << bytes << std::endl;
                     break;
                } 
    }

}

It is not working on different machines and the camera is'nt opening on client side for capturing the video .what to do

It is not working on different machines and the camera is'nt opening on client side for capturing the video .what to do

Hi @mahika2,

Looking at the code, it’s only the server that accesses the web camera. The client only displays frames sent from the server.

Yes sorry on the server side the camera is'nt opening.when i run the code web camera light gets on for 1 sec without opening of camera and then turns off. And there is nothing recorded. Atlast its also not working on different machines idk why.

Yes sorry on the server side the camera is'nt opening.when i run the code web camera light gets on for 1 sec without opening of camera and then turns off. And there is nothing recorded. Atlast its also not working on different machines idk why.

Did you modify the server code? From your previous screenshots it seems you’re running Ubuntu in virtualbox, are you sure ubuntu has full access to your webcam?

no i didn't modify the code.for other codes the camera is working for example for capturing video through opencv the camera works fine.

please tell me the solution for this error

it runs only for single thread and then exit.

Yes sorry on the server side the camera is'nt opening.when i run the code web camera light gets on for 1 sec without opening of camera and then turns off. And there is nothing recorded. Atlast its also not working on different machines idk why.

For it to work on different machines, instead of using 127.0.0.1(localhost), you have to use the ip address of the machine running the server.

please tell me the solution for this error

Hi @ujjwalgoyal65,

Those are just warnings, you can ignore them. C++ just doesn't like the way the variable is being converted.

I installed opencv4.1.1 and everything works for me.
At this point I'm not sure what's wrong.

can u plz mail me the client and server code .
emial id:- [email protected]

Hi everyone
please I have a question regarding video savage at the client level, that it is sent from a server. You can tell me which lines of code to add

Hi everyone
please I have a question regarding video savage at the client level, that it is sent from a server. You can tell me which lines of code to add

*void send_data(void ptr)

this code work very well , but when one thread end , the streaming stop for all others threads

Can you share the makefile or CMAkeLists.txt file to run the above scripts?

Hi,
thanks for your code, to change this code to UDP, what should we do?

just replace SOCK_STREAM to SOCK_DGRAM, It works I tested
Thanks