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Object Hierarchy
GObject ╰── GInitiallyUnowned ╰── GstObject ╰── GstClock ╰── GstSystemClock ╰── GstNetClientClock ╰── GstNtpClock
Description
GstNetClientClock implements a custom GstClock that synchronizes its time to a remote time provider such as GstNetTimeProvider. GstNtpClock implements a GstClock that synchronizes its time to a remote NTPv4 server.
A new clock is created with gst_net_client_clock_new() or
gst_ntp_clock_new(), which takes the address and port of the remote time
provider along with a name and an initial time.
This clock will poll the time provider and will update its calibration parameters based on the local and remote observations.
The "round-trip" property limits the maximum round trip packets can take.
Various parameters of the clock can be configured with the parent GstClock "timeout", "window-size" and "window-threshold" object properties.
A GstNetClientClock and GstNtpClock is typically set on a GstPipeline with
gst_pipeline_use_clock().
If you set a GstBus on the clock via the "bus" object property, it will
send GST_MESSAGE_ELEMENT
messages with an attached GstStructure containing
statistics about clock accuracy and network traffic.
Functions
gst_net_client_clock_new ()
GstClock * gst_net_client_clock_new (const gchar *name,const gchar *remote_address,gint remote_port,GstClockTime base_time);
Create a new GstNetClientInternalClock that will report the time
provided by the GstNetTimeProvider on remote_address
and
remote_port
.
gst_ntp_clock_new ()
GstClock * gst_ntp_clock_new (const gchar *name,const gchar *remote_address,gint remote_port,GstClockTime base_time);
Create a new GstNtpClock that will report the time provided by
the NTPv4 server on remote_address
and remote_port
.
Parameters
name |
a name for the clock |
|
remote_address |
the address or hostname of the remote clock provider |
|
remote_port |
the port of the remote clock provider |
|
base_time |
initial time of the clock |
Since: 1.6
Property Details
The “address” property
“address” gchar *
The IP address of the machine providing a time server.
Flags: Read / Write / Construct
Default value: "127.0.0.1"
The “base-time” property
“base-time” guint64
Initial time that is reported before synchronization.
Flags: Read / Write / Construct Only
Default value: 0
The “bus” property
“bus” GstBus *
A GstBus on which to send clock status information.
Flags: Read / Write
The “internal-clock” property
“internal-clock” GstClock *
Internal clock that directly slaved to the remote clock.
Flags: Read
The “minimum-update-interval” property
“minimum-update-interval” guint64
Minimum polling interval for packets, in nanoseconds(0 = no limit).
Flags: Read / Write
Default value: 50000000
The “port” property
“port” gint
The port on which the remote server is listening.
Flags: Read / Write / Construct
Allowed values: [0,65535]
Default value: 5637
The “qos-dscp” property
“qos-dscp” gint
Quality of Service, differentiated services code point (-1 default).
Flags: Read / Write
Allowed values: [-1,63]
Default value: -1
The “round-trip-limit” property
“round-trip-limit” guint64
Maximum tolerable round-trip interval for packets, in nanoseconds (0 = no limit).
Flags: Read / Write
Default value: 1000000000