/* * Network playback synchronization * Copyright (C) 2009 Google Inc. * * This file is part of MPlayer. * * MPlayer is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * MPlayer is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with MPlayer; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #if !HAVE_WINSOCK2_H #include #include #include #include #include #include #include #include #include #include #include #else #include #include #endif /* HAVE_WINSOCK2_H */ #include "mplayer.h" #include "mp_core.h" #include "mp_msg.h" #include "help_mp.h" #include "udp_sync.h" #include "osdep/timer.h" // config options for UDP sync int udp_master = 0; int udp_slave = 0; int udp_port = 23867; const char *udp_ip = "127.0.0.1"; // where the master sends datagrams // (can be a broadcast address) float udp_seek_threshold = 1.0; // how far off before we seek // how far off is still considered equal #define UDP_TIMING_TOLERANCE 0.02 static void startup(void) { #if HAVE_WINSOCK2_H static int wsa_started; if (!wsa_started) { WSADATA wd; WSAStartup(0x0202, &wd); wsa_started = 1; } #endif } static void set_blocking(int fd, int blocking) { long sock_flags; #if HAVE_WINSOCK2_H sock_flags = !blocking; ioctlsocket(fd, FIONBIO, &sock_flags); #else sock_flags = fcntl(fd, F_GETFL, 0); sock_flags = blocking ? sock_flags & ~O_NONBLOCK : sock_flags | O_NONBLOCK; fcntl(fd, F_SETFL, sock_flags); #endif /* HAVE_WINSOCK2_H */ } // gets a datagram from the master with or without blocking. updates // master_position if successful. if the master has exited, returns 1. // returns -1 on error or if no message received. // otherwise, returns 0. static int get_udp(int blocking, double *master_position) { char mesg[100]; int chars_received = -1; int n; static int sockfd = -1; if (sockfd == -1) { #if HAVE_WINSOCK2_H DWORD tv = 30000; #else struct timeval tv = { .tv_sec = 30 }; #endif struct sockaddr_in servaddr = { 0 }; startup(); sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (sockfd == -1) return -1; servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl(INADDR_ANY); servaddr.sin_port = htons(udp_port); bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)); setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)); } set_blocking(sockfd, blocking); while (-1 != (n = recvfrom(sockfd, mesg, sizeof(mesg)-1, 0, NULL, NULL))) { char *end; // flush out any further messages so we don't get behind if (chars_received == -1) set_blocking(sockfd, 0); chars_received = n; mesg[chars_received] = 0; if (strcmp(mesg, "bye") == 0) return 1; *master_position = strtod(mesg, &end); if (*end) { mp_msg(MSGT_CPLAYER, MSGL_WARN, "Could not parse udp string!\n"); return -1; } } if (chars_received == -1) return -1; return 0; } void send_udp(const char *send_to_ip, int port, char *mesg) { static int sockfd = -1; static struct sockaddr_in socketinfo; if (sockfd == -1) { static const int one = 1; int ip_valid = 0; startup(); sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (sockfd == -1) exit_player(EXIT_ERROR); // Enable broadcast setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)); #if HAVE_WINSOCK2_H socketinfo.sin_addr.s_addr = inet_addr(send_to_ip); ip_valid = socketinfo.sin_addr.s_addr != INADDR_NONE; #else ip_valid = inet_aton(send_to_ip, &socketinfo.sin_addr); #endif if (!ip_valid) { mp_msg(MSGT_CPLAYER, MSGL_FATAL, MSGTR_InvalidIP); exit_player(EXIT_ERROR); } socketinfo.sin_family = AF_INET; socketinfo.sin_port = htons(port); } sendto(sockfd, mesg, strlen(mesg), 0, (struct sockaddr *) &socketinfo, sizeof(socketinfo)); } // this function makes sure we stay as close as possible to the master's // position. returns 1 if the master tells us to exit, // -1 on error and normal timing should be used again, 0 otherwise. int udp_slave_sync(MPContext *mpctx) { // remember where the master is in the file static double udp_master_position; // whether we timed out before waiting for a master message static int timed_out = -1; // last time we received a valid master message static unsigned last_success; int master_exited; if (timed_out < 0) { // initialize udp_master_position = mpctx->sh_video->pts - udp_seek_threshold / 2; timed_out = 0; last_success = GetTimerMS(); } // grab any waiting datagrams without blocking master_exited = get_udp(0, &udp_master_position); while (!master_exited || (!timed_out && master_exited < 0)) { double my_position = mpctx->sh_video->pts; // if we're way off, seek to catch up if (FFABS(my_position - udp_master_position) > udp_seek_threshold) { abs_seek_pos = SEEK_ABSOLUTE; rel_seek_secs = udp_master_position; break; } // normally we expect that the master will have just played the // frame we're ready to play. break out and play it, and we'll be // right in sync. // or, the master might be up to a few seconds ahead of us, in // which case we also want to play the current frame immediately, // without waiting. // UDP_TIMING_TOLERANCE is a small value that lets us consider // the master equal to us even if it's very slightly ahead. if (udp_master_position + UDP_TIMING_TOLERANCE > my_position) break; // the remaining case is that we're slightly ahead of the master. // usually, it just means we called get_udp() before the datagram // arrived. call get_udp again, but this time block until we receive // a datagram. master_exited = get_udp(1, &udp_master_position); if (master_exited < 0) timed_out = 1; } if (master_exited >= 0) { last_success = GetTimerMS(); timed_out = 0; } else { master_exited = 0; timed_out |= GetTimerMS() - last_success > 30000; } return timed_out ? -1 : master_exited; }