1 /*****************************************************************************
2 * netsync.c: synchronization between several network clients.
3 *****************************************************************************
4 * Copyright (C) 2004-2009 the VideoLAN team
7 * Authors: Gildas Bazin <gbazin@videolan.org>
8 * Jean-Paul Saman <jpsaman@videolan.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
35 #include <vlc_interface.h>
36 #include <vlc_input.h>
37 #include <vlc_playlist.h>
39 #include <sys/types.h>
45 #include <vlc_network.h>
47 #define NETSYNC_PORT 9875
49 /*****************************************************************************
51 *****************************************************************************/
52 static int Open (vlc_object_t *);
53 static void Close(vlc_object_t *);
55 #define NETSYNC_TEXT N_("Network master clock")
56 #define NETSYNC_LONGTEXT N_("When set, " \
57 "this VLC instance will act as the master clock for synchronization " \
58 "for clients listening")
60 #define MIP_TEXT N_("Master server ip address")
61 #define MIP_LONGTEXT N_("The IP address of " \
62 "the network master clock to use for clock synchronization.")
64 #define NETSYNC_TIMEOUT_TEXT N_("UDP timeout (in ms)")
65 #define NETSYNC_TIMEOUT_LONGTEXT N_("Length of time (in ms) " \
66 "until aborting data reception.")
69 set_shortname(N_("Network Sync"))
70 set_description(N_("Network synchronization"))
71 set_category(CAT_ADVANCED)
72 set_subcategory(SUBCAT_ADVANCED_MISC)
74 add_bool("netsync-master", false,
75 NETSYNC_TEXT, NETSYNC_LONGTEXT, true)
76 add_string("netsync-master-ip", NULL, MIP_TEXT, MIP_LONGTEXT,
78 add_integer("netsync-timeout", 500,
79 NETSYNC_TIMEOUT_TEXT, NETSYNC_TIMEOUT_LONGTEXT, true)
81 set_capability("interface", 0)
82 set_callbacks(Open, Close)
85 /*****************************************************************************
87 *****************************************************************************/
95 input_thread_t *input;
99 static int PlaylistEvent(vlc_object_t *, char const *cmd,
100 vlc_value_t oldval, vlc_value_t newval, void *data);
102 /*****************************************************************************
103 * Activate: initialize and create stuff
104 *****************************************************************************/
105 static int Open(vlc_object_t *object)
107 intf_thread_t *intf = (intf_thread_t*)object;
111 if (!var_InheritBool(intf, "netsync-master")) {
112 char *psz_master = var_InheritString(intf, "netsync-master-ip");
113 if (psz_master == NULL) {
114 msg_Err(intf, "master address not specified");
117 fd = net_ConnectUDP(VLC_OBJECT(intf), psz_master, NETSYNC_PORT, -1);
120 fd = net_ListenUDP1(VLC_OBJECT(intf), NULL, NETSYNC_PORT);
124 msg_Err(intf, "Netsync socket failure");
128 intf->p_sys = sys = malloc(sizeof(*sys));
135 sys->is_master = var_InheritBool(intf, "netsync-master");
136 sys->timeout = var_InheritInteger(intf, "netsync-timeout");
137 if (sys->timeout < 500)
139 sys->playlist = pl_Get(intf);
142 var_AddCallback(sys->playlist, "input-current", PlaylistEvent, intf);
146 /*****************************************************************************
147 * Close: destroy interface
148 *****************************************************************************/
149 void Close(vlc_object_t *object)
151 intf_thread_t *intf = (intf_thread_t*)object;
152 intf_sys_t *sys = intf->p_sys;
154 assert(sys->input == NULL);
155 var_DelCallback(sys->playlist, "input-current", PlaylistEvent, intf);
160 static mtime_t GetPcrSystem(input_thread_t *input)
162 int canc = vlc_savecancel();
163 /* TODO use the delay */
165 if (input_GetPcrSystem(input, &system, NULL))
167 vlc_restorecancel(canc);
172 static void *Master(void *handle)
174 intf_thread_t *intf = handle;
175 intf_sys_t *sys = intf->p_sys;
177 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
180 if (poll(&ufd, 1, -1) < 0)
183 /* We received something */
184 struct sockaddr_storage from;
185 unsigned struct_size = sizeof(from);
186 recvfrom(sys->fd, data, sizeof(data), 0,
187 (struct sockaddr*)&from, &struct_size);
189 mtime_t master_system = GetPcrSystem(sys->input);
190 if (master_system < 0)
193 data[0] = hton64(mdate());
194 data[1] = hton64(master_system);
196 /* Reply to the sender */
197 sendto(sys->fd, data, sizeof(data), 0,
198 (struct sockaddr *)&from, struct_size);
200 /* not sure we need the client information to sync,
201 since we are the master anyway */
202 mtime_t client_system = ntoh64(data[0]);
203 msg_Dbg(intf, "Master clockref: %"PRId64" -> %"PRId64", from %s "
204 "(date: %"PRId64")", client_system, master_system,
205 (from.ss_family == AF_INET) ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
206 : "non-IPv4", /*date*/ 0);
212 static void *Slave(void *handle)
214 intf_thread_t *intf = handle;
215 intf_sys_t *sys = intf->p_sys;
218 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
221 mtime_t system = GetPcrSystem(sys->input);
225 /* Send clock request to the master */
226 data[0] = hton64(system);
228 const mtime_t send_date = mdate();
229 if (send(sys->fd, data, sizeof(data[0]), 0) <= 0)
233 if (poll(&ufd, 1, sys->timeout) <= 0)
236 const mtime_t receive_date = mdate();
237 if (recv(sys->fd, data, sizeof(data), 0) <= 0)
240 const mtime_t master_date = ntoh64(data[0]);
241 const mtime_t master_system = ntoh64(data[1]);
242 const mtime_t diff_date = receive_date -
243 ((receive_date - send_date) / 2 + master_date);
245 if (master_system > 0) {
246 int canc = vlc_savecancel();
248 mtime_t client_system;
249 if (!input_GetPcrSystem(sys->input, &client_system, NULL)) {
250 const mtime_t diff_system = client_system - master_system - diff_date;
251 if (diff_system != 0) {
252 input_ModifyPcrSystem(sys->input, true, master_system - diff_date);
254 msg_Dbg(intf, "Slave clockref: %"PRId64" -> %"PRId64" -> %"PRId64","
255 " clock diff: %"PRId64", diff: %"PRId64"",
256 system, master_system, client_system,
257 diff_system, diff_date);
261 vlc_restorecancel(canc);
264 msleep(INTF_IDLE_SLEEP);
269 static int InputEvent(vlc_object_t *object, char const *cmd,
270 vlc_value_t oldval, vlc_value_t newval, void *data)
272 VLC_UNUSED(cmd); VLC_UNUSED(oldval); VLC_UNUSED(object);
273 intf_thread_t *intf = data;
274 intf_sys_t *sys = intf->p_sys;
276 if (newval.i_int == INPUT_EVENT_DEAD && sys->input) {
277 msg_Err(intf, "InputEvent DEAD");
278 vlc_cancel(sys->thread);
279 vlc_join(sys->thread, NULL);
280 vlc_object_release(sys->input);
286 static int PlaylistEvent(vlc_object_t *object, char const *cmd,
287 vlc_value_t oldval, vlc_value_t newval, void *data)
289 VLC_UNUSED(cmd); VLC_UNUSED(oldval); VLC_UNUSED(object);
290 intf_thread_t *intf = data;
291 intf_sys_t *sys = intf->p_sys;
293 input_thread_t *input = newval.p_address;
294 assert(sys->input == NULL);
295 sys->input = vlc_object_hold(input);
296 if (vlc_clone(&sys->thread, sys->is_master ? Master : Slave, intf,
297 VLC_THREAD_PRIORITY_INPUT)) {
298 vlc_object_release(input);
301 var_AddCallback(input, "intf-event", InputEvent, intf);