Сохранить медиа-поток в файл

#include <iostream>
#include <stdio.h>
#include <fcntl.h>
 
#if defined(__linux__)
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #include <netdb.h>
#elif defined(_WIN32)
    #include <winsock2.h>
#else
    #error "Cannot determine OS type"
#endif
 
#define TIMEOUT 5000
//mg - multicast group
#define port_mg 3425
#define ip_mg "237.7.7.7"
 
using namespace std;
 
//Receiving Transport Stream from Multicast Group
void receive_from(int ic_sock)
{
    size_t bytes_read;
 
    char buf[1024];
    int i = 1;
    cout << "Source: udp://" << ip_mg << ":" << port_mg << endl;
    while(true)
    {
        bytes_read = recvfrom(ic_sock, buf, 1024, 0, NULL, NULL);
        buf[bytes_read] = '\0';
        if (0 <= bytes_read)
        {
            cout << i << ". Read bytes - " << bytes_read << endl;
        }
        else
        {
            break;
        }
        i++;
    }
}
 
int main()
{
    //Create socket
    int incoming_sock, rc;
    incoming_sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (incoming_sock < 0)
    {
        perror("socket");
        return -1;
    }
    cout << "socket: Success" << endl;
 
    //Bind socket with local interface
    struct sockaddr_in saddr;
    saddr.sin_family = AF_INET;
    saddr.sin_addr.s_addr = INADDR_ANY;
    saddr.sin_port = htons(port_mg);
    rc = bind(incoming_sock, (struct sockaddr *)&saddr, sizeof(struct sockaddr_in));
    if (rc != 0)
    {
        perror("bind");
        return -2;
    }
    cout << "bind: Success" << endl;
 
    //Join to multicast group
    struct ip_mreq  mreq;
    mreq.imr_interface.s_addr = INADDR_ANY;
    inet_aton(ip_mg, &mreq.imr_multiaddr);
 
    //Adjuct socket for receiving
    rc = setsockopt(incoming_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (const char*) &mreq, sizeof(mreq));
    if (rc != 0)
    {
        perror("setsockopt");
        return -3;
    }
    cout << "setsockopt: Success" << endl;
 
    receive_from(incoming_sock);
 
    close(incoming_sock);
 
    return 0;
}