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 /// \bug [String] This string is BAD.
60 #define NETSYNC_TEXT N_( "Act as master" )
61 #define NETSYNC_LONGTEXT N_( "Should " \
62 "act as the master client for the network synchronisation?" )
64 /// \bug [String] This string is BAD.
65 #define MIP_TEXT N_( "Master client ip address" )
66 #define MIP_LONGTEXT N_( "IP address of " \
67 "the master client used for the network synchronisation." )
70 set_shortname( _("Network Sync"));
71 set_description( _("Network synchronisation") );
72 set_category( CAT_ADVANCED );
73 set_subcategory( SUBCAT_ADVANCED_MISC );
75 add_bool( "netsync-master", 0, NULL,
76 NETSYNC_TEXT, NETSYNC_LONGTEXT, VLC_TRUE );
77 add_string( "netsync-master-ip", NULL, NULL, MIP_TEXT, MIP_LONGTEXT,
80 set_capability( "interface", 0 );
81 set_callbacks( Activate, Close );
86 input_thread_t *p_input;
89 /*****************************************************************************
91 *****************************************************************************/
92 static void Run( intf_thread_t *p_intf );
94 /*****************************************************************************
95 * Activate: initialize and create stuff
96 *****************************************************************************/
97 static int Activate( vlc_object_t *p_this )
99 intf_thread_t *p_intf = (intf_thread_t*)p_this;
101 p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
104 msg_Err( p_intf, "no memory" );
108 p_intf->p_sys->p_input = NULL;
110 p_intf->pf_run = Run;
114 /*****************************************************************************
115 * Close: destroy interface
116 *****************************************************************************/
117 void Close( vlc_object_t *p_this )
119 intf_thread_t *p_intf = (intf_thread_t*)p_this;
121 free( p_intf->p_sys );
124 /*****************************************************************************
125 * Run: interface thread
126 *****************************************************************************/
127 static void Run( intf_thread_t *p_intf )
129 #define MAX_MSG_LENGTH (2 * sizeof(int64_t))
131 vlc_bool_t b_master = config_GetInt( p_intf, "netsync-master" );
132 char *psz_master = NULL;
133 char p_data[MAX_MSG_LENGTH];
138 psz_master = config_GetPsz( p_intf, "netsync-master-ip" );
139 if( psz_master == NULL )
141 msg_Err( p_intf, "master address not specified" );
147 i_socket = net_ListenUDP1( p_intf, NULL, NETSYNC_PORT );
149 i_socket = net_ConnectUDP( p_intf, psz_master, NETSYNC_PORT, 0 );
151 if( psz_master ) free( psz_master );
155 msg_Err( p_intf, "failed opening UDP socket" ); /* str review: is this good enough? */
159 /* High priority thread */
160 vlc_thread_set_priority( p_intf, VLC_THREAD_PRIORITY_INPUT );
162 while( !intf_ShouldDie( p_intf ) )
164 struct timeval timeout;
167 /* Update the input */
168 if( p_intf->p_sys->p_input == NULL )
170 p_intf->p_sys->p_input =
171 (input_thread_t *)vlc_object_find( p_intf, VLC_OBJECT_INPUT,
174 else if( p_intf->p_sys->p_input->b_dead )
176 vlc_object_release( p_intf->p_sys->p_input );
177 p_intf->p_sys->p_input = NULL;
180 if( p_intf->p_sys->p_input == NULL )
183 msleep( INTF_IDLE_SLEEP );
188 * We now have an input
191 /* Initialize file descriptor set and timeout (0.5s) */
193 FD_SET( i_socket, &fds_r );
195 timeout.tv_usec = 500000;
199 struct sockaddr_storage from;
200 mtime_t i_date, i_clockref, i_master_clockref;
201 int i_struct_size, i_read, i_ret;
204 i_ret = select( i_socket + 1, &fds_r, 0, 0, &timeout );
205 if( i_ret == 0 ) continue;
209 msleep( INTF_IDLE_SLEEP );
213 /* We received something */
214 i_struct_size = sizeof( from );
215 i_read = recvfrom( i_socket, p_data, MAX_MSG_LENGTH, 0,
216 (struct sockaddr*)&from,
217 (unsigned int *)&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 ) ==