How to transfer cv::VideoCapture frames through socket in client-server model (OpenCV C++)?

Question

I translate video through socket and I see video stream in other side but I cant receive video. My video file is empty. I am thinking the problem can be wrong convert video

Answer 1

Env: OpenCV 3.3, G++5.4, Ubuntu 16.04

---

If you want to save the video, you should set CV_FOURCE to MJPG。

VideoWriter outputVideo;
Size S = Size((int) 640,(int) 480);
outputVideo.open("receive.avi", CV_FOURCC('M','J','P','G'), 30, S, true);

---

This is my result:

Code as follow:

客户端(Client.cpp):

//!2017.12.19 19:19:01 CST
//!2017.12.19 22:19:38 CST
//!2017.12.19 22:39:37 CST
// 客户端
// 使用 OpenCV 读取视频（并处理），然后使用 SOCKET 上传到服务器。

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;
using namespace cv;

int main()
{
    int sock;
    struct sockaddr_in addr;

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if(sock < 0){
        perror("socket");
        exit(1);
    }

    addr.sin_family = AF_INET;
    addr.sin_port = htons(3425);
    addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

    if(connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0){
        perror("connect");
        exit(2);
    }

    int bbytee;
    cout << "before open the cam" << endl;

    VideoCapture cap(0);

    if(!cap.isOpened()) {
        cout<< "Could not open the camera" <<  endl;
        close(sock);
        return -1;
    }

    Mat frame;
    frame = Mat::zeros(480, 640, CV_8UC3);
    int imgSize = frame.cols*frame.rows*3;

    int cnt=0;
    //Mat frame;
    while(1) {
        cap >> frame;
        if(frame.empty()) {
            cerr<<"[client] VideoCapture(0) error!"<

---

服务端(Server.cpp):

//!2017.12.19 19:19:01 CST
//!2017.12.19 22:19:38 CST
//!2017.12.19 22:39:37 CST
// 服务器
// 监听客户端请求，读取视频流（并处理），保存。
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;
using namespace cv;

int main()
{
    int sock, listener;
    struct sockaddr_in addr;

    if( (listener = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("[server] socket() failed");
        exit(1);
    }

    addr.sin_family = AF_INET;
    addr.sin_port = htons(3425);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if(bind(listener, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
        perror("[server] binding faild!");
        exit(2);
    }

    listen(listener, 1);


    int num_of_recv_bytes;
    VideoWriter outputVideo;
    Size S = Size((int) 640,(int) 480);
    outputVideo.open("receive.avi", CV_FOURCC('M','J','P','G'), 30, S, true);

    int imgSize = 480*640*3;
    Mat frame = Mat::zeros(480, 640, CV_8UC3);
    uchar *iptr = frame.data;
    int key;

    int cnt=0;
    while(1){
        cout << ++cnt<= 0) break;
        }
        outputVideo.release();
        close(sock);
        break;
    }
    return 0;
}