/***************************************************************************** * netsync.c: synchronisation between several network clients. ***************************************************************************** * Copyright (C) 2004 VideoLAN * $Id$ * * Authors: Gildas Bazin * * This program 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. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ /***************************************************************************** * Preamble *****************************************************************************/ #include #include #include #include #ifdef HAVE_UNISTD_H # include #endif #ifdef HAVE_SYS_TIME_H # include #endif #include #ifdef WIN32 # include # include # ifndef IN_MULTICAST # define IN_MULTICAST(a) IN_CLASSD(a) # endif #else # include # include # if HAVE_ARPA_INET_H # include # elif defined( SYS_BEOS ) # include # endif #endif #ifdef UNDER_CE # define close(a) CloseHandle(a); #elif defined( WIN32 ) # define close(a) closesocket(a); #endif #include "network.h" #define NETSYNC_PORT_MASTER 9875 #define NETSYNC_PORT_SLAVE 9876 /* Needed for Solaris */ #ifndef INADDR_NONE #define INADDR_NONE 0xffffffff #endif /***************************************************************************** * Module descriptor *****************************************************************************/ static int Activate( vlc_object_t * ); static void Close ( vlc_object_t * ); static mtime_t GetClockRef( intf_thread_t *, mtime_t ); #define NETSYNC_TEXT N_( "Act as master for network synchronisation" ) #define NETSYNC_LONGTEXT N_( "Allows you to specify if this client should " \ "act as the master client for the network synchronisation." ) #define MIP_TEXT N_( "Master client ip address" ) #define MIP_LONGTEXT N_( "Allows you to specify the ip address of " \ "the master client used for the network synchronisation." ) vlc_module_begin(); set_description( _("Network synchronisation") ); add_bool( "netsync-master", 0, NULL, NETSYNC_TEXT, NETSYNC_LONGTEXT, VLC_TRUE ); add_string( "netsync-master-ip", NULL, NULL, MIP_TEXT, MIP_LONGTEXT, VLC_TRUE ); set_capability( "interface", 0 ); set_callbacks( Activate, Close ); vlc_module_end(); struct intf_sys_t { input_thread_t *p_input; }; /***************************************************************************** * Local prototypes *****************************************************************************/ static void Run( intf_thread_t *p_intf ); /***************************************************************************** * Activate: initialize and create stuff *****************************************************************************/ static int Activate( vlc_object_t *p_this ) { intf_thread_t *p_intf = (intf_thread_t*)p_this; msg_Info( p_intf, "Using the netsync interface module..." ); p_intf->p_sys = malloc( sizeof( intf_sys_t ) ); if( !p_intf->p_sys ) { msg_Err( p_intf, "no memory" ); return VLC_ENOMEM; } p_intf->p_sys->p_input = NULL; p_intf->pf_run = Run; return VLC_SUCCESS; } /***************************************************************************** * Close: destroy interface *****************************************************************************/ void Close( vlc_object_t *p_this ) { intf_thread_t *p_intf = (intf_thread_t*)p_this; free( p_intf->p_sys ); } /***************************************************************************** * Run: interface thread *****************************************************************************/ static void Run( intf_thread_t *p_intf ) { #define MAX_MSG_LENGTH (2 * sizeof(int64_t)) vlc_bool_t b_master = config_GetInt( p_intf, "netsync-master" ); char *psz_master = NULL; char p_data[MAX_MSG_LENGTH]; int i_socket; if( !b_master ) { psz_master = config_GetPsz( p_intf, "netsync-master-ip" ); if( psz_master == NULL ) { msg_Err( p_intf, "master address not specified" ); return; } } i_socket = net_OpenUDP( p_intf, NULL, b_master ? NETSYNC_PORT_MASTER : NETSYNC_PORT_SLAVE, b_master ? NULL : psz_master, b_master ? 0 : NETSYNC_PORT_MASTER ); if( psz_master ) free( psz_master ); if( i_socket < 0 ) { msg_Err( p_intf, "failed opening UDP socket." ); return; } /* High priority thread */ vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT ); while( !p_intf->b_die ) { struct timeval timeout; fd_set fds_r; /* Update the input */ if( p_intf->p_sys->p_input == NULL ) { p_intf->p_sys->p_input = (input_thread_t *)vlc_object_find( p_intf, VLC_OBJECT_INPUT, FIND_ANYWHERE ); } else if( p_intf->p_sys->p_input->b_dead ) { vlc_object_release( p_intf->p_sys->p_input ); p_intf->p_sys->p_input = NULL; } if( p_intf->p_sys->p_input == NULL ) { /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); continue; } /* * We now have an input */ /* Initialize file descriptor set and timeout (0.5s) */ FD_ZERO( &fds_r ); FD_SET( i_socket, &fds_r ); timeout.tv_sec = 0; timeout.tv_usec = 500000; if( b_master ) { struct sockaddr_storage from; mtime_t i_date, i_clockref, i_master_clockref; int i_struct_size, i_read, i_ret; /* Don't block */ i_ret = select( i_socket + 1, &fds_r, 0, 0, &timeout ); if( i_ret == 0 ) continue; if( i_ret < 0 ) { /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); continue; } /* We received something */ i_struct_size = sizeof( from ); i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0, (struct sockaddr*)&from, &i_struct_size ); i_clockref = ntoh64(*(int64_t *)p_data); i_date = mdate(); *(int64_t *)p_data = hton64( i_date ); i_master_clockref = GetClockRef( p_intf, i_clockref ); *(((int64_t *)p_data)+1) = hton64( i_master_clockref ); /* Reply to the sender */ sendto( i_socket, p_data, 2 * sizeof(int64_t), 0, (struct sockaddr *)&from, i_struct_size ); msg_Dbg( p_intf, "Master clockref: "I64Fd" -> "I64Fd", from %s " "(date: "I64Fd")", i_clockref, i_master_clockref, from.ss_family == AF_INET ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr) : "non-IPv4", i_date ); } else { mtime_t i_send_date, i_receive_date, i_master_date, i_diff_date; mtime_t i_master_clockref, i_client_clockref, i_drift; mtime_t i_clockref = 0; int i_sent, i_read, i_ret; /* Send clock request to the master */ *(int64_t *)p_data = hton64( i_clockref ); i_send_date = mdate(); i_sent = send( i_socket, p_data, sizeof(int64_t), 0 ); if( i_sent <= 0 ) { /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); continue; } /* Don't block */ i_ret = select(i_socket + 1, &fds_r, 0, 0, &timeout); if( i_ret == 0 ) continue; if( i_ret < 0 ) { /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); continue; } i_receive_date = mdate(); i_read = recv( i_socket, p_data, MAX_MSG_LENGTH, 0 ); if( i_read <= 0 ) { /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); continue; } i_master_date = ntoh64(*(int64_t *)p_data); i_master_clockref = ntoh64(*(((int64_t *)p_data)+1)); i_diff_date = i_receive_date - ((i_receive_date - i_send_date) / 2 + i_master_date); i_client_clockref = i_drift = 0; if( p_intf->p_sys->p_input && i_master_clockref ) { i_client_clockref = GetClockRef( p_intf, i_clockref ); i_drift = i_client_clockref - i_master_clockref - i_diff_date; /* Update our clock to match the master's one */ if( i_client_clockref ) p_intf->p_sys->p_input->i_pts_delay -= i_drift; } msg_Dbg( p_intf, "Slave clockref: "I64Fd" -> "I64Fd" -> "I64Fd", " "clock diff: "I64Fd" drift: "I64Fd, i_clockref, i_master_clockref, i_client_clockref, i_diff_date, i_drift ); /* Wait a bit */ msleep( INTF_IDLE_SLEEP ); } } if( p_intf->p_sys->p_input ) vlc_object_release( p_intf->p_sys->p_input ); net_Close( i_socket ); } static mtime_t GetClockRef( intf_thread_t *p_intf, mtime_t i_pts ) { input_thread_t *p_input = p_intf->p_sys->p_input; mtime_t i_ts; if( !p_input || !p_input->p_es_out ) return 0; if( es_out_Control( p_input->p_es_out, ES_OUT_GET_TS, i_pts, &i_ts ) == VLC_SUCCESS ) { return i_ts; } return 0; }