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 var_DelCallback(sys->playlist, "input-current", PlaylistEvent, intf);
156 if (sys->input != NULL) {
157 vlc_cancel(sys->thread);
158 vlc_join(sys->thread, NULL);
165 static mtime_t GetPcrSystem(input_thread_t *input)
167 int canc = vlc_savecancel();
168 /* TODO use the delay */
170 if (input_GetPcrSystem(input, &system, NULL))
172 vlc_restorecancel(canc);
177 static void *Master(void *handle)
179 intf_thread_t *intf = handle;
180 intf_sys_t *sys = intf->p_sys;
182 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
185 if (poll(&ufd, 1, -1) < 0)
188 /* We received something */
189 struct sockaddr_storage from;
190 socklen_t fromlen = sizeof (from);
192 if (recvfrom(sys->fd, data, 8, 0,
193 (struct sockaddr *)&from, &fromlen) < 8)
196 mtime_t master_system = GetPcrSystem(sys->input);
197 if (master_system < 0)
200 data[0] = hton64(mdate());
201 data[1] = hton64(master_system);
203 /* Reply to the sender */
204 sendto(sys->fd, data, 16, 0,
205 (struct sockaddr *)&from, fromlen);
207 /* not sure we need the client information to sync,
208 since we are the master anyway */
209 mtime_t client_system = ntoh64(data[0]);
210 msg_Dbg(intf, "Master clockref: %"PRId64" -> %"PRId64", from %s "
211 "(date: %"PRId64")", client_system, master_system,
212 (from.ss_family == AF_INET) ? inet_ntoa(((struct sockaddr_in *)&from)->sin_addr)
213 : "non-IPv4", /*date*/ 0);
219 static void *Slave(void *handle)
221 intf_thread_t *intf = handle;
222 intf_sys_t *sys = intf->p_sys;
225 struct pollfd ufd = { .fd = sys->fd, .events = POLLIN, };
228 mtime_t system = GetPcrSystem(sys->input);
232 /* Send clock request to the master */
233 const mtime_t send_date = mdate();
235 data[0] = hton64(system);
236 send(sys->fd, data, 8, 0);
239 if (poll(&ufd, 1, sys->timeout) <= 0)
242 const mtime_t receive_date = mdate();
243 if (recv(sys->fd, data, 16, 0) < 16)
246 const mtime_t master_date = ntoh64(data[0]);
247 const mtime_t master_system = ntoh64(data[1]);
248 const mtime_t diff_date = receive_date -
249 ((receive_date - send_date) / 2 + master_date);
251 if (master_system > 0) {
252 int canc = vlc_savecancel();
254 mtime_t client_system;
255 if (!input_GetPcrSystem(sys->input, &client_system, NULL)) {
256 const mtime_t diff_system = client_system - master_system - diff_date;
257 if (diff_system != 0) {
258 input_ModifyPcrSystem(sys->input, true, master_system - diff_date);
260 msg_Dbg(intf, "Slave clockref: %"PRId64" -> %"PRId64" -> %"PRId64","
261 " clock diff: %"PRId64", diff: %"PRId64"",
262 system, master_system, client_system,
263 diff_system, diff_date);
267 vlc_restorecancel(canc);
270 msleep(INTF_IDLE_SLEEP);
275 static int PlaylistEvent(vlc_object_t *object, char const *cmd,
276 vlc_value_t oldval, vlc_value_t newval, void *data)
278 VLC_UNUSED(cmd); VLC_UNUSED(object);
279 intf_thread_t *intf = data;
280 intf_sys_t *sys = intf->p_sys;
281 input_thread_t *input = newval.p_address;
283 if (sys->input != NULL) {
284 msg_Err(intf, "InputEvent DEAD");
285 assert(oldval.p_address == sys->input);
287 vlc_cancel(sys->thread);
288 vlc_join(sys->thread, NULL);
294 if (vlc_clone(&sys->thread, sys->is_master ? Master : Slave, intf,
295 VLC_THREAD_PRIORITY_INPUT))