1 /*****************************************************************************
2 * netsync.c: synchronisation between several network clients.
3 *****************************************************************************
4 * Copyright (C) 2004 the VideoLAN team
7 * Authors: Gildas Bazin <gbazin@videolan.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
30 #include <vlc/input.h>
35 #ifdef HAVE_SYS_TIME_H
36 # include <sys/time.h>
38 #ifdef HAVE_SYS_TYPES_H
39 # include <sys/types.h>
44 #define NETSYNC_PORT 9875
46 /* Needed for Solaris */
48 #define INADDR_NONE 0xffffffff
51 /*****************************************************************************
53 *****************************************************************************/
54 static int Activate( vlc_object_t * );
55 static void Close ( vlc_object_t * );
57 static mtime_t GetClockRef( intf_thread_t *, mtime_t );
59 #define NETSYNC_TEXT N_( "Act as master for network synchronisation" )
60 #define NETSYNC_LONGTEXT N_( "Allows you to specify if this client should " \
61 "act as the master client for the network synchronisation." )
63 #define MIP_TEXT N_( "Master client ip address" )
64 #define MIP_LONGTEXT N_( "Allows you to specify the ip address of " \
65 "the master client used for the network synchronisation." )
68 set_shortname( _("Network Sync"));
69 set_description( _("Network synchronisation") );
70 set_category( CAT_ADVANCED );
71 set_subcategory( SUBCAT_ADVANCED_MISC );
73 add_bool( "netsync-master", 0, NULL,
74 NETSYNC_TEXT, NETSYNC_LONGTEXT, VLC_TRUE );
75 add_string( "netsync-master-ip", NULL, NULL, MIP_TEXT, MIP_LONGTEXT,
78 set_capability( "interface", 0 );
79 set_callbacks( Activate, Close );
84 input_thread_t *p_input;
87 /*****************************************************************************
89 *****************************************************************************/
90 static void Run( intf_thread_t *p_intf );
92 /*****************************************************************************
93 * Activate: initialize and create stuff
94 *****************************************************************************/
95 static int Activate( vlc_object_t *p_this )
97 intf_thread_t *p_intf = (intf_thread_t*)p_this;
99 p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
102 msg_Err( p_intf, "no memory" );
106 p_intf->p_sys->p_input = NULL;
108 p_intf->pf_run = Run;
112 /*****************************************************************************
113 * Close: destroy interface
114 *****************************************************************************/
115 void Close( vlc_object_t *p_this )
117 intf_thread_t *p_intf = (intf_thread_t*)p_this;
119 free( p_intf->p_sys );
122 /*****************************************************************************
123 * Run: interface thread
124 *****************************************************************************/
125 static void Run( intf_thread_t *p_intf )
127 #define MAX_MSG_LENGTH (2 * sizeof(int64_t))
129 vlc_bool_t b_master = config_GetInt( p_intf, "netsync-master" );
130 char *psz_master = NULL;
131 char p_data[MAX_MSG_LENGTH];
136 psz_master = config_GetPsz( p_intf, "netsync-master-ip" );
137 if( psz_master == NULL )
139 msg_Err( p_intf, "master address not specified" );
145 i_socket = net_OpenUDP( p_intf, NULL, NETSYNC_PORT, NULL, 0 );
147 i_socket = net_ConnectUDP( p_intf, psz_master, NETSYNC_PORT, 0 );
149 if( psz_master ) free( psz_master );
153 msg_Err( p_intf, "failed opening UDP socket." );
157 /* High priority thread */
158 vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT );
160 while( !p_intf->b_die )
162 struct timeval timeout;
165 /* Update the input */
166 if( p_intf->p_sys->p_input == NULL )
168 p_intf->p_sys->p_input =
169 (input_thread_t *)vlc_object_find( p_intf, VLC_OBJECT_INPUT,
172 else if( p_intf->p_sys->p_input->b_dead )
174 vlc_object_release( p_intf->p_sys->p_input );
175 p_intf->p_sys->p_input = NULL;
178 if( p_intf->p_sys->p_input == NULL )
181 msleep( INTF_IDLE_SLEEP );
186 * We now have an input
189 /* Initialize file descriptor set and timeout (0.5s) */
191 FD_SET( i_socket, &fds_r );
193 timeout.tv_usec = 500000;
197 struct sockaddr_storage from;
198 mtime_t i_date, i_clockref, i_master_clockref;
199 int i_struct_size, i_read, i_ret;
202 i_ret = select( i_socket + 1, &fds_r, 0, 0, &timeout );
203 if( i_ret == 0 ) continue;
207 msleep( INTF_IDLE_SLEEP );
211 /* We received something */
212 i_struct_size = sizeof( from );
213 i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0,
214 (struct sockaddr*)&from, &i_struct_size );
216 i_clockref = ntoh64(*(int64_t *)p_data);
219 *(int64_t *)p_data = hton64( i_date );
221 i_master_clockref = GetClockRef( p_intf, i_clockref );
222 *(((int64_t *)p_data)+1) = hton64( i_master_clockref );
224 /* Reply to the sender */
225 sendto( i_socket, p_data, 2 * sizeof(int64_t), 0,
226 (struct sockaddr *)&from, i_struct_size );
229 msg_Dbg( p_intf, "Master clockref: "I64Fd" -> "I64Fd", from %s "
230 "(date: "I64Fd")", i_clockref, i_master_clockref,
231 from.ss_family == AF_INET
232 ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
233 : "non-IPv4", i_date );
238 mtime_t i_send_date, i_receive_date, i_master_date, i_diff_date;
239 mtime_t i_master_clockref, i_client_clockref, i_drift;
240 mtime_t i_clockref = 0;
241 int i_sent, i_read, i_ret;
243 /* Send clock request to the master */
244 *(int64_t *)p_data = hton64( i_clockref );
245 i_send_date = mdate();
247 i_sent = send( i_socket, p_data, sizeof(int64_t), 0 );
251 msleep( INTF_IDLE_SLEEP );
256 i_ret = select(i_socket + 1, &fds_r, 0, 0, &timeout);
257 if( i_ret == 0 ) continue;
261 msleep( INTF_IDLE_SLEEP );
265 i_receive_date = mdate();
267 i_read = recv( i_socket, p_data, MAX_MSG_LENGTH, 0 );
271 msleep( INTF_IDLE_SLEEP );
275 i_master_date = ntoh64(*(int64_t *)p_data);
276 i_master_clockref = ntoh64(*(((int64_t *)p_data)+1));
278 i_diff_date = i_receive_date -
279 ((i_receive_date - i_send_date) / 2 + i_master_date);
281 i_client_clockref = i_drift = 0;
282 if( p_intf->p_sys->p_input && i_master_clockref )
284 i_client_clockref = GetClockRef( p_intf, i_clockref );
285 i_drift = i_client_clockref - i_master_clockref - i_diff_date;
287 /* Update our clock to match the master's one */
288 if( i_client_clockref )
289 p_intf->p_sys->p_input->i_pts_delay -= i_drift;
293 msg_Dbg( p_intf, "Slave clockref: "I64Fd" -> "I64Fd" -> "I64Fd", "
294 "clock diff: "I64Fd" drift: "I64Fd,
295 i_clockref, i_master_clockref,
296 i_client_clockref, i_diff_date, i_drift );
300 msleep( INTF_IDLE_SLEEP );
304 if( p_intf->p_sys->p_input ) vlc_object_release( p_intf->p_sys->p_input );
305 net_Close( i_socket );
308 static mtime_t GetClockRef( intf_thread_t *p_intf, mtime_t i_pts )
310 input_thread_t *p_input = p_intf->p_sys->p_input;
313 if( !p_input || !p_input->p_es_out ) return 0;
315 if( es_out_Control( p_input->p_es_out, ES_OUT_GET_TS, i_pts, &i_ts ) ==