How to solve: sending UDP packet using Sendto() got “message too long”

Question

I want to use the sendto() API to send video and audio data through UDP packet. The sending buffer size I got using getsockopt() is 114688, however, sendto() returned -1 wh

Answer 1

Why not just call sendto several times, with an offset into the buffer?

int sendto_bigbuffer(int sock, const void *buffer, const size_t buflen, int flags,
                     const struct sockaddr *dest_addr, socklen_t addrlen)
{
    size_t sendlen = MIN(buflen, 1024);
    size_t remlen  = buflen;
    const void *curpos = buffer;

    while (remlen > 0)
    {
        ssize_t len = sendto(sock, curpos, sendlen, flags, dest_addr, addrlen);
        if (len == -1)
            return -1;

        curpos += len;
        remlen -= len;
        sendlen = MIN(remlen, 1024);
    }

    return buflen;
}

Something like the above function will send the buffer 1024 bytes at a time.