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>
42 #include <sys/types.h>
47 #include <vlc_network.h>
49 #define NETSYNC_PORT 9875
51 /*****************************************************************************
53 *****************************************************************************/
54 static int Open (vlc_object_t *);
55 static void Close(vlc_object_t *);
57 #define NETSYNC_TEXT N_("Network master clock")
58 #define NETSYNC_LONGTEXT N_("When set, " \
59 "this VLC instance will act as the master clock for synchronization " \
60 "for clients listening")
62 #define MIP_TEXT N_("Master server ip address")
63 #define MIP_LONGTEXT N_("The IP address of " \
64 "the network master clock to use for clock synchronization.")
66 #define NETSYNC_TIMEOUT_TEXT N_("UDP timeout (in ms)")
67 #define NETSYNC_TIMEOUT_LONGTEXT N_("Length of time (in ms) " \
68 "until aborting data reception.")
71 set_shortname(N_("Network Sync"))
72 set_description(N_("Network synchronization"))
73 set_category(CAT_ADVANCED)
74 set_subcategory(SUBCAT_ADVANCED_MISC)
76 add_bool("netsync-master", false,
77 NETSYNC_TEXT, NETSYNC_LONGTEXT, true)
78 add_string("netsync-master-ip", NULL, MIP_TEXT, MIP_LONGTEXT,
80 add_integer("netsync-timeout", 500,
81 NETSYNC_TIMEOUT_TEXT, NETSYNC_TIMEOUT_LONGTEXT, true)
83 set_capability("interface", 0)
84 set_callbacks(Open, Close)
87 /*****************************************************************************
89 *****************************************************************************/
97 input_thread_t *input;
101 static int PlaylistEvent(vlc_object_t *, char const *cmd,
102 vlc_value_t oldval, vlc_value_t newval, void *data);
104 /*****************************************************************************
105 * Activate: initialize and create stuff
106 *****************************************************************************/
107 static int Open(vlc_object_t *object)
109 intf_thread_t *intf = (intf_thread_t*)object;
113 if (!var_InheritBool(intf, "netsync-master")) {
114 char *psz_master = var_InheritString(intf, "netsync-master-ip");
115 if (psz_master == NULL) {
116 msg_Err(intf, "master address not specified");
119 fd = net_ConnectUDP(VLC_OBJECT(intf), psz_master, NETSYNC_PORT, -1);
122 fd = net_ListenUDP1(VLC_OBJECT(intf), NULL, NETSYNC_PORT);
126 msg_Err(intf, "Netsync socket failure");
131 intf->p_sys = sys = malloc(sizeof(*sys));
138 sys->is_master = var_InheritBool(intf, "netsync-master");
139 sys->timeout = var_InheritInteger(intf, "netsync-timeout");
140 if (sys->timeout < 500)
142 sys->playlist = pl_Get(intf);
145 var_AddCallback(sys->playlist, "input-current", PlaylistEvent, intf);
149 /*****************************************************************************
150 * Close: destroy interface
151 *****************************************************************************/
152 void Close(vlc_object_t *object)
154 intf_thread_t *intf = (intf_thread_t*)object;
155 intf_sys_t *sys = intf->p_sys;
157 assert(sys->input == NULL);
158 var_DelCallback(sys->playlist, "input-current", PlaylistEvent, intf);
163 static mtime_t GetPcrSystem(input_thread_t *input)
165 int canc = vlc_savecancel();
166 /* TODO use the delay */
168 if (input_GetPcrSystem(input, &system, NULL))
170 vlc_restorecancel(canc);
175 static void *Master(void *handle)
177 intf_thread_t *intf = handle;
178 intf_sys_t *sys = intf->p_sys;
180 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
183 if (poll(&ufd, 1, -1) < 0)
186 /* We received something */
187 struct sockaddr_storage from;
188 unsigned struct_size = sizeof(from);
189 recvfrom(sys->fd, data, sizeof(data), 0,
190 (struct sockaddr*)&from, &struct_size);
192 mtime_t master_system = GetPcrSystem(sys->input);
193 if (master_system < 0)
196 data[0] = hton64(mdate());
197 data[1] = hton64(master_system);
199 /* Reply to the sender */
200 sendto(sys->fd, data, sizeof(data), 0,
201 (struct sockaddr *)&from, struct_size);
203 /* not sure we need the client information to sync,
204 since we are the master anyway */
205 mtime_t client_system = ntoh64(data[0]);
206 msg_Dbg(intf, "Master clockref: %"PRId64" -> %"PRId64", from %s "
207 "(date: %"PRId64")", client_system, master_system,
208 (from.ss_family == AF_INET) ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
209 : "non-IPv4", /*date*/ 0);
215 static void *Slave(void *handle)
217 intf_thread_t *intf = handle;
218 intf_sys_t *sys = intf->p_sys;
221 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
224 mtime_t system = GetPcrSystem(sys->input);
228 /* Send clock request to the master */
229 data[0] = hton64(system);
231 const mtime_t send_date = mdate();
232 if (send(sys->fd, data, sizeof(data[0]), 0) <= 0)
236 if (poll(&ufd, 1, sys->timeout) <= 0)
239 const mtime_t receive_date = mdate();
240 if (recv(sys->fd, data, sizeof(data), 0) <= 0)
243 const mtime_t master_date = ntoh64(data[0]);
244 const mtime_t master_system = ntoh64(data[1]);
245 const mtime_t diff_date = receive_date -
246 ((receive_date - send_date) / 2 + master_date);
248 if (master_system > 0) {
249 int canc = vlc_savecancel();
251 mtime_t client_system;
252 if (!input_GetPcrSystem(sys->input, &client_system, NULL)) {
253 const mtime_t diff_system = client_system - master_system - diff_date;
254 if (diff_system != 0) {
255 input_ModifyPcrSystem(sys->input, true, master_system - diff_date);
257 msg_Dbg(intf, "Slave clockref: %"PRId64" -> %"PRId64" -> %"PRId64","
258 " clock diff: %"PRId64", diff: %"PRId64"",
259 system, master_system, client_system,
260 diff_system, diff_date);
264 vlc_restorecancel(canc);
267 msleep(INTF_IDLE_SLEEP);
272 static int InputEvent(vlc_object_t *object, char const *cmd,
273 vlc_value_t oldval, vlc_value_t newval, void *data)
275 VLC_UNUSED(cmd); VLC_UNUSED(oldval); VLC_UNUSED(object);
276 intf_thread_t *intf = data;
277 intf_sys_t *sys = intf->p_sys;
279 if (newval.i_int == INPUT_EVENT_DEAD && sys->input) {
280 msg_Err(intf, "InputEvent DEAD");
281 vlc_cancel(sys->thread);
282 vlc_join(sys->thread, NULL);
283 vlc_object_release(sys->input);
289 static int PlaylistEvent(vlc_object_t *object, char const *cmd,
290 vlc_value_t oldval, vlc_value_t newval, void *data)
292 VLC_UNUSED(cmd); VLC_UNUSED(oldval); VLC_UNUSED(object);
293 intf_thread_t *intf = data;
294 intf_sys_t *sys = intf->p_sys;
296 input_thread_t *input = newval.p_address;
297 assert(sys->input == NULL);
298 sys->input = vlc_object_hold(input);
299 if (vlc_clone(&sys->thread, sys->is_master ? Master : Slave, intf,
300 VLC_THREAD_PRIORITY_INPUT)) {
301 vlc_object_release(input);
304 var_AddCallback(input, "intf-event", InputEvent, intf);