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., 59 Temple Place - Suite 330, Boston, MA 02111, 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_MASTER 9875
45 #define NETSYNC_PORT_SLAVE 9876
47 /* Needed for Solaris */
49 #define INADDR_NONE 0xffffffff
52 /*****************************************************************************
54 *****************************************************************************/
55 static int Activate( vlc_object_t * );
56 static void Close ( vlc_object_t * );
58 static mtime_t GetClockRef( intf_thread_t *, mtime_t );
60 #define NETSYNC_TEXT N_( "Act as master for network synchronisation" )
61 #define NETSYNC_LONGTEXT N_( "Allows you to specify if this client should " \
62 "act as the master client for the network synchronisation." )
64 #define MIP_TEXT N_( "Master client ip address" )
65 #define MIP_LONGTEXT N_( "Allows you to specify the ip address of " \
66 "the master client used for the network synchronisation." )
69 set_shortname( _("Netsync"));
70 set_description( _("Network synchronisation") );
71 set_category( CAT_INTERFACE );
72 set_subcategory( SUBCAT_INTERFACE_CONTROL );
74 add_bool( "netsync-master", 0, NULL,
75 NETSYNC_TEXT, NETSYNC_LONGTEXT, VLC_TRUE );
76 add_string( "netsync-master-ip", NULL, NULL, MIP_TEXT, MIP_LONGTEXT,
79 set_capability( "interface", 0 );
80 set_callbacks( Activate, Close );
85 input_thread_t *p_input;
88 /*****************************************************************************
90 *****************************************************************************/
91 static void Run( intf_thread_t *p_intf );
93 /*****************************************************************************
94 * Activate: initialize and create stuff
95 *****************************************************************************/
96 static int Activate( vlc_object_t *p_this )
98 intf_thread_t *p_intf = (intf_thread_t*)p_this;
100 msg_Info( p_intf, "Using the netsync interface module..." );
102 p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
105 msg_Err( p_intf, "no memory" );
109 p_intf->p_sys->p_input = NULL;
111 p_intf->pf_run = Run;
115 /*****************************************************************************
116 * Close: destroy interface
117 *****************************************************************************/
118 void Close( vlc_object_t *p_this )
120 intf_thread_t *p_intf = (intf_thread_t*)p_this;
122 free( p_intf->p_sys );
125 /*****************************************************************************
126 * Run: interface thread
127 *****************************************************************************/
128 static void Run( intf_thread_t *p_intf )
130 #define MAX_MSG_LENGTH (2 * sizeof(int64_t))
132 vlc_bool_t b_master = config_GetInt( p_intf, "netsync-master" );
133 char *psz_master = NULL;
134 char p_data[MAX_MSG_LENGTH];
139 psz_master = config_GetPsz( p_intf, "netsync-master-ip" );
140 if( psz_master == NULL )
142 msg_Err( p_intf, "master address not specified" );
147 i_socket = net_OpenUDP( p_intf, NULL,
148 b_master ? NETSYNC_PORT_MASTER : NETSYNC_PORT_SLAVE,
149 b_master ? NULL : psz_master,
150 b_master ? 0 : NETSYNC_PORT_MASTER );
152 if( psz_master ) free( psz_master );
156 msg_Err( p_intf, "failed opening UDP socket." );
160 /* High priority thread */
161 vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT );
163 while( !p_intf->b_die )
165 struct timeval timeout;
168 /* Update the input */
169 if( p_intf->p_sys->p_input == NULL )
171 p_intf->p_sys->p_input =
172 (input_thread_t *)vlc_object_find( p_intf, VLC_OBJECT_INPUT,
175 else if( p_intf->p_sys->p_input->b_dead )
177 vlc_object_release( p_intf->p_sys->p_input );
178 p_intf->p_sys->p_input = NULL;
181 if( p_intf->p_sys->p_input == NULL )
184 msleep( INTF_IDLE_SLEEP );
189 * We now have an input
192 /* Initialize file descriptor set and timeout (0.5s) */
194 FD_SET( i_socket, &fds_r );
196 timeout.tv_usec = 500000;
200 struct sockaddr_storage from;
201 mtime_t i_date, i_clockref, i_master_clockref;
202 int i_struct_size, i_read, i_ret;
205 i_ret = select( i_socket + 1, &fds_r, 0, 0, &timeout );
206 if( i_ret == 0 ) continue;
210 msleep( INTF_IDLE_SLEEP );
214 /* We received something */
215 i_struct_size = sizeof( from );
216 i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0,
217 (struct sockaddr*)&from, &i_struct_size );
219 i_clockref = ntoh64(*(int64_t *)p_data);
222 *(int64_t *)p_data = hton64( i_date );
224 i_master_clockref = GetClockRef( p_intf, i_clockref );
225 *(((int64_t *)p_data)+1) = hton64( i_master_clockref );
227 /* Reply to the sender */
228 sendto( i_socket, p_data, 2 * sizeof(int64_t), 0,
229 (struct sockaddr *)&from, i_struct_size );
232 msg_Dbg( p_intf, "Master clockref: "I64Fd" -> "I64Fd", from %s "
233 "(date: "I64Fd")", i_clockref, i_master_clockref,
234 from.ss_family == AF_INET
235 ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
236 : "non-IPv4", i_date );
241 mtime_t i_send_date, i_receive_date, i_master_date, i_diff_date;
242 mtime_t i_master_clockref, i_client_clockref, i_drift;
243 mtime_t i_clockref = 0;
244 int i_sent, i_read, i_ret;
246 /* Send clock request to the master */
247 *(int64_t *)p_data = hton64( i_clockref );
248 i_send_date = mdate();
250 i_sent = send( i_socket, p_data, sizeof(int64_t), 0 );
254 msleep( INTF_IDLE_SLEEP );
259 i_ret = select(i_socket + 1, &fds_r, 0, 0, &timeout);
260 if( i_ret == 0 ) continue;
264 msleep( INTF_IDLE_SLEEP );
268 i_receive_date = mdate();
270 i_read = recv( i_socket, p_data, MAX_MSG_LENGTH, 0 );
274 msleep( INTF_IDLE_SLEEP );
278 i_master_date = ntoh64(*(int64_t *)p_data);
279 i_master_clockref = ntoh64(*(((int64_t *)p_data)+1));
281 i_diff_date = i_receive_date -
282 ((i_receive_date - i_send_date) / 2 + i_master_date);
284 i_client_clockref = i_drift = 0;
285 if( p_intf->p_sys->p_input && i_master_clockref )
287 i_client_clockref = GetClockRef( p_intf, i_clockref );
288 i_drift = i_client_clockref - i_master_clockref - i_diff_date;
290 /* Update our clock to match the master's one */
291 if( i_client_clockref )
292 p_intf->p_sys->p_input->i_pts_delay -= i_drift;
296 msg_Dbg( p_intf, "Slave clockref: "I64Fd" -> "I64Fd" -> "I64Fd", "
297 "clock diff: "I64Fd" drift: "I64Fd,
298 i_clockref, i_master_clockref,
299 i_client_clockref, i_diff_date, i_drift );
303 msleep( INTF_IDLE_SLEEP );
307 if( p_intf->p_sys->p_input ) vlc_object_release( p_intf->p_sys->p_input );
308 net_Close( i_socket );
311 static mtime_t GetClockRef( intf_thread_t *p_intf, mtime_t i_pts )
313 input_thread_t *p_input = p_intf->p_sys->p_input;
316 if( !p_input || !p_input->p_es_out ) return 0;
318 if( es_out_Control( p_input->p_es_out, ES_OUT_GET_TS, i_pts, &i_ts ) ==