2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2005 Wim Taymans <wim@fluendo.com>
4 * 2005 Andy Wingo <wingo@pobox.com>
5 * Copyright (C) 2012 Collabora Ltd. <tim.muller@collabora.co.uk>
7 * gstnetclientclock.h: clock that synchronizes itself to a time provider over
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Library General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
15 * This library 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 GNU
18 * Library General Public License for more details.
20 * You should have received a copy of the GNU Library General Public
21 * License along with this library; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 02111-1307, USA.
26 * SECTION:gstnetclientclock
27 * @short_description: Special clock that synchronizes to a remote time
29 * @see_also: #GstClock, #GstNetTimeProvider, #GstPipeline
31 * This object implements a custom #GstClock that synchronizes its time
32 * to a remote time provider such as #GstNetTimeProvider.
34 * A new clock is created with gst_net_client_clock_new() which takes the
35 * address and port of the remote time provider along with a name and
38 * This clock will poll the time provider and will update its calibration
39 * parameters based on the local and remote observations.
41 * Various parameters of the clock can be configured with the parent #GstClock
42 * "timeout", "window-size" and "window-threshold" object properties.
44 * A #GstNetClientClock is typically set on a #GstPipeline with
45 * gst_pipeline_use_clock().
47 * Last reviewed on 2005-11-23 (0.9.5)
54 #include "gstnettimepacket.h"
55 #include "gstnetclientclock.h"
59 GST_DEBUG_CATEGORY_STATIC (ncc_debug);
60 #define GST_CAT_DEFAULT (ncc_debug)
62 #define DEFAULT_ADDRESS "127.0.0.1"
63 #define DEFAULT_PORT 5637
64 #define DEFAULT_TIMEOUT GST_SECOND
73 #define GST_NET_CLIENT_CLOCK_GET_PRIVATE(obj) \
74 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_NET_CLIENT_CLOCK, GstNetClientClockPrivate))
76 struct _GstNetClientClockPrivate
81 GSocketAddress *servaddr;
84 GstClockTime timeout_expiration;
91 GST_DEBUG_CATEGORY_INIT (ncc_debug, "netclock", 0, "Network client clock");
92 #define gst_net_client_clock_parent_class parent_class
93 G_DEFINE_TYPE_WITH_CODE (GstNetClientClock, gst_net_client_clock,
94 GST_TYPE_SYSTEM_CLOCK, _do_init);
96 static void gst_net_client_clock_finalize (GObject * object);
97 static void gst_net_client_clock_set_property (GObject * object, guint prop_id,
98 const GValue * value, GParamSpec * pspec);
99 static void gst_net_client_clock_get_property (GObject * object, guint prop_id,
100 GValue * value, GParamSpec * pspec);
102 static void gst_net_client_clock_stop (GstNetClientClock * self);
105 gst_net_client_clock_class_init (GstNetClientClockClass * klass)
107 GObjectClass *gobject_class;
109 gobject_class = G_OBJECT_CLASS (klass);
111 g_type_class_add_private (klass, sizeof (GstNetClientClockPrivate));
113 gobject_class->finalize = gst_net_client_clock_finalize;
114 gobject_class->get_property = gst_net_client_clock_get_property;
115 gobject_class->set_property = gst_net_client_clock_set_property;
117 g_object_class_install_property (gobject_class, PROP_ADDRESS,
118 g_param_spec_string ("address", "address",
119 "The IP address of the machine providing a time server",
120 DEFAULT_ADDRESS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
121 g_object_class_install_property (gobject_class, PROP_PORT,
122 g_param_spec_int ("port", "port",
123 "The port on which the remote server is listening", 0, G_MAXUINT16,
124 DEFAULT_PORT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
128 gst_net_client_clock_init (GstNetClientClock * self)
130 GstClock *clock = GST_CLOCK_CAST (self);
132 self->priv = GST_NET_CLIENT_CLOCK_GET_PRIVATE (self);
134 self->priv->port = DEFAULT_PORT;
135 self->priv->address = g_strdup (DEFAULT_ADDRESS);
137 clock->timeout = DEFAULT_TIMEOUT;
139 self->priv->thread = NULL;
141 self->priv->servaddr = NULL;
145 gst_net_client_clock_finalize (GObject * object)
147 GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
149 if (self->priv->thread) {
150 gst_net_client_clock_stop (self);
153 g_free (self->priv->address);
154 self->priv->address = NULL;
156 if (self->priv->servaddr != NULL) {
157 g_object_unref (self->priv->servaddr);
158 self->priv->servaddr = NULL;
161 if (self->priv->socket != NULL) {
162 g_socket_close (self->priv->socket, NULL);
163 g_object_unref (self->priv->socket);
164 self->priv->socket = NULL;
167 G_OBJECT_CLASS (parent_class)->finalize (object);
171 gst_net_client_clock_set_property (GObject * object, guint prop_id,
172 const GValue * value, GParamSpec * pspec)
174 GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
178 g_free (self->priv->address);
179 self->priv->address = g_value_dup_string (value);
180 if (self->priv->address == NULL)
181 self->priv->address = g_strdup (DEFAULT_ADDRESS);
184 self->priv->port = g_value_get_int (value);
187 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
193 gst_net_client_clock_get_property (GObject * object, guint prop_id,
194 GValue * value, GParamSpec * pspec)
196 GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
200 g_value_set_string (value, self->priv->address);
203 g_value_set_int (value, self->priv->port);
206 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
212 gst_net_client_clock_observe_times (GstNetClientClock * self,
213 GstClockTime local_1, GstClockTime remote, GstClockTime local_2)
215 GstClockTime current_timeout;
216 GstClockTime local_avg;
220 if (local_2 < local_1)
221 goto bogus_observation;
223 local_avg = (local_2 + local_1) / 2;
225 clock = GST_CLOCK_CAST (self);
227 gst_clock_add_observation (GST_CLOCK (self), local_avg, remote, &r_squared);
229 GST_CLOCK_SLAVE_LOCK (self);
230 if (clock->filling) {
234 current_timeout = (1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;
235 current_timeout = MIN (current_timeout, clock->timeout);
237 GST_INFO ("next timeout: %" GST_TIME_FORMAT, GST_TIME_ARGS (current_timeout));
238 self->priv->timeout_expiration = gst_util_get_timestamp () + current_timeout;
239 GST_CLOCK_SLAVE_UNLOCK (clock);
245 GST_WARNING_OBJECT (self, "time packet receive time < send time (%"
246 GST_TIME_FORMAT " < %" GST_TIME_FORMAT ")", GST_TIME_ARGS (local_1),
247 GST_TIME_ARGS (local_2));
255 GstNetClientClock *clock;
257 } GstNetClientClockTimeoutSource;
260 gst_net_client_clock_timeout_source_prepare (GSource * s, gint * p_timeout)
262 GstNetClientClockTimeoutSource *source = (GstNetClientClockTimeoutSource *) s;
263 GstClockTime expiration_time = source->clock->priv->timeout_expiration;
264 GstClockTime now = gst_util_get_timestamp ();
266 if (now >= expiration_time || (expiration_time - now) <= GST_MSECOND) {
271 *p_timeout = (expiration_time - now) / GST_MSECOND;
272 GST_TRACE_OBJECT (source->clock, "time out in %d ms please", *p_timeout);
277 gst_net_client_clock_timeout_source_check (GSource * s)
279 GstNetClientClockTimeoutSource *source = (GstNetClientClockTimeoutSource *) s;
281 return (gst_util_get_timestamp () >= source->clock->priv->timeout_expiration);
285 gst_net_client_clock_timeout_source_dispatch (GSource * s, GSourceFunc cb,
288 GstNetClientClockTimeoutSource *source = (GstNetClientClockTimeoutSource *) s;
290 GST_TRACE_OBJECT (source->clock, "timed out");
291 *source->p_timeout = TRUE;
296 gst_net_client_clock_socket_cb (GSocket * socket, GIOCondition condition,
299 GIOCondition *p_cond = user_data;
301 GST_TRACE ("socket %p I/O condition: 0x%02x", socket, condition);
307 gst_net_client_clock_thread (gpointer data)
309 GstNetClientClock *self = data;
310 GstNetTimePacket *packet;
312 GSourceFuncs funcs = { NULL, };
316 GSocket *socket = self->priv->socket;
318 GstClock *clock = data;
320 GST_INFO_OBJECT (self, "net client clock thread running, socket=%p", socket);
322 g_socket_set_blocking (socket, TRUE);
323 g_socket_set_timeout (socket, 0);
325 ctx = g_main_context_new ();
327 source = g_socket_create_source (socket, G_IO_IN, self->priv->cancel);
328 g_source_set_name (source, "GStreamer net client clock thread socket");
329 g_source_set_callback (source, (GSourceFunc) gst_net_client_clock_socket_cb,
331 g_source_attach (source, ctx);
332 g_source_unref (source);
334 /* GSocket only support second granularity for timeouts, so roll our own
335 * timeout source (so we don't have to create a new source whenever the
336 * timeout changes, as we would have to do with the default timeout source) */
337 funcs.prepare = gst_net_client_clock_timeout_source_prepare;
338 funcs.check = gst_net_client_clock_timeout_source_check;
339 funcs.dispatch = gst_net_client_clock_timeout_source_dispatch;
340 funcs.finalize = NULL;
341 source = g_source_new (&funcs, sizeof (GstNetClientClockTimeoutSource));
342 ((GstNetClientClockTimeoutSource *) source)->clock = self;
343 ((GstNetClientClockTimeoutSource *) source)->p_timeout = &timeout;
344 g_source_set_name (source, "GStreamer net client clock timeout");
345 g_source_attach (source, ctx);
346 g_source_unref (source);
348 while (!g_cancellable_is_cancelled (self->priv->cancel)) {
351 g_main_context_iteration (ctx, TRUE);
353 if (g_cancellable_is_cancelled (self->priv->cancel))
357 /* timed out, let's send another packet */
358 GST_DEBUG_OBJECT (self, "timed out");
360 packet = gst_net_time_packet_new (NULL);
362 packet->local_time = gst_clock_get_internal_time (GST_CLOCK (self));
364 GST_DEBUG_OBJECT (self, "sending packet, local time = %" GST_TIME_FORMAT,
365 GST_TIME_ARGS (packet->local_time));
367 gst_net_time_packet_send (packet, self->priv->socket,
368 self->priv->servaddr, NULL);
372 /* reset timeout (but are expecting a response sooner anyway) */
373 self->priv->timeout_expiration =
374 gst_util_get_timestamp () + clock->timeout;
378 /* got data to read? */
379 if ((cond & G_IO_IN)) {
380 GstClockTime new_local;
382 new_local = gst_clock_get_internal_time (GST_CLOCK (self));
384 packet = gst_net_time_packet_receive (socket, NULL, &err);
387 GST_WARNING_OBJECT (self, "receive error: %s", err->message);
393 GST_LOG_OBJECT (self, "got packet back");
394 GST_LOG_OBJECT (self, "local_1 = %" GST_TIME_FORMAT,
395 GST_TIME_ARGS (packet->local_time));
396 GST_LOG_OBJECT (self, "remote = %" GST_TIME_FORMAT,
397 GST_TIME_ARGS (packet->remote_time));
398 GST_LOG_OBJECT (self, "local_2 = %" GST_TIME_FORMAT,
399 GST_TIME_ARGS (new_local));
401 /* observe_times will reset the timeout */
402 gst_net_client_clock_observe_times (self, packet->local_time,
403 packet->remote_time, new_local);
409 if ((cond & (G_IO_ERR | G_IO_HUP))) {
410 GST_DEBUG_OBJECT (self, "socket error?! %s", g_strerror (errno));
411 g_usleep (G_USEC_PER_SEC / 10);
416 GST_INFO_OBJECT (self, "shutting down net client clock thread");
417 g_main_context_unref (ctx);
422 gst_net_client_clock_start (GstNetClientClock * self)
424 GSocketAddress *servaddr;
425 GSocketAddress *myaddr;
426 GInetAddress *inetaddr;
428 GError *error = NULL;
430 g_return_val_if_fail (self->priv->address != NULL, FALSE);
431 g_return_val_if_fail (self->priv->servaddr == NULL, FALSE);
433 socket = g_socket_new (G_SOCKET_FAMILY_IPV4, G_SOCKET_TYPE_DATAGRAM,
434 G_SOCKET_PROTOCOL_UDP, &error);
439 /* check address we're bound to, mostly for debugging purposes */
440 myaddr = g_socket_get_local_address (socket, &error);
443 goto getsockname_error;
445 GST_DEBUG_OBJECT (self, "socket opened on UDP port %hd",
446 g_inet_socket_address_get_port (G_INET_SOCKET_ADDRESS (myaddr)));
448 g_object_unref (myaddr);
450 /* create target address */
451 inetaddr = g_inet_address_new_from_string (self->priv->address);
453 if (inetaddr == NULL)
456 servaddr = g_inet_socket_address_new (inetaddr, self->priv->port);
457 g_object_unref (inetaddr);
459 g_assert (servaddr != NULL);
461 GST_DEBUG_OBJECT (self, "will communicate with %s:%d", self->priv->address,
464 self->priv->cancel = g_cancellable_new ();
465 self->priv->socket = socket;
466 self->priv->servaddr = G_SOCKET_ADDRESS (servaddr);
468 #if !GLIB_CHECK_VERSION (2, 31, 0)
469 self->priv->thread = g_thread_create (gst_net_client_clock_thread, self, TRUE,
472 self->priv->thread = g_thread_try_new ("GstNetClientClock",
473 gst_net_client_clock_thread, self, &error);
484 GST_ERROR_OBJECT (self, "socket_new() failed: %s", error->message);
485 g_error_free (error);
490 GST_ERROR_OBJECT (self, "get_local_address() failed: %s", error->message);
491 g_error_free (error);
492 g_object_unref (socket);
497 GST_ERROR_OBJECT (self, "inet_address_new_from_string('%s') failed",
498 self->priv->address);
499 g_object_unref (socket);
504 GST_ERROR_OBJECT (self, "could not create thread: %s", error->message);
505 g_object_unref (self->priv->servaddr);
506 self->priv->servaddr = NULL;
507 g_object_unref (self->priv->socket);
508 self->priv->socket = NULL;
509 g_error_free (error);
515 gst_net_client_clock_stop (GstNetClientClock * self)
517 if (self->priv->thread == NULL)
520 GST_INFO_OBJECT (self, "stopping...");
521 g_cancellable_cancel (self->priv->cancel);
523 g_thread_join (self->priv->thread);
524 self->priv->thread = NULL;
526 g_object_unref (self->priv->cancel);
527 self->priv->cancel = NULL;
529 g_object_unref (self->priv->servaddr);
530 self->priv->servaddr = NULL;
532 g_object_unref (self->priv->socket);
533 self->priv->socket = NULL;
535 GST_INFO_OBJECT (self, "stopped");
539 * gst_net_client_clock_new:
540 * @name: a name for the clock
541 * @remote_address: the address of the remote clock provider
542 * @remote_port: the port of the remote clock provider
543 * @base_time: initial time of the clock
545 * Create a new #GstNetClientClock that will report the time
546 * provided by the #GstNetTimeProvider on @remote_address and
549 * Returns: a new #GstClock that receives a time from the remote
553 gst_net_client_clock_new (gchar * name, const gchar * remote_address,
554 gint remote_port, GstClockTime base_time)
556 /* FIXME: gst_net_client_clock_new() should be a thin wrapper for g_object_new() */
557 GstNetClientClock *ret;
558 GstClockTime internal;
560 g_return_val_if_fail (remote_address != NULL, NULL);
561 g_return_val_if_fail (remote_port > 0, NULL);
562 g_return_val_if_fail (remote_port <= G_MAXUINT16, NULL);
563 g_return_val_if_fail (base_time != GST_CLOCK_TIME_NONE, NULL);
565 ret = g_object_new (GST_TYPE_NET_CLIENT_CLOCK, "address", remote_address,
566 "port", remote_port, NULL);
568 /* gst_clock_get_time() values are guaranteed to be increasing. because no one
569 * has called get_time on this clock yet we are free to adjust to any value
570 * without worrying about worrying about MAX() issues with the clock's
574 /* update our internal time so get_time() give something around base_time.
575 assume that the rate is 1 in the beginning. */
576 internal = gst_clock_get_internal_time (GST_CLOCK (ret));
577 gst_clock_set_calibration (GST_CLOCK (ret), internal, base_time, 1, 1);
580 GstClockTime now = gst_clock_get_time (GST_CLOCK (ret));
582 if (GST_CLOCK_DIFF (now, base_time) > 0 ||
583 GST_CLOCK_DIFF (now, base_time + GST_SECOND) < 0) {
584 g_warning ("unable to set the base time, expect sync problems!");
588 if (!gst_net_client_clock_start (ret))
591 /* all systems go, cap'n */
592 return (GstClock *) ret;
596 /* already printed a nice error */
597 gst_object_unref (ret);