forked from mirrors/gstreamer-rs
140 lines
5 KiB
Markdown
140 lines
5 KiB
Markdown
<!-- file * -->
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<!-- struct NetClientClock -->
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`NetClientClock` implements a custom `gst::Clock` that synchronizes its time
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to a remote time provider such as `NetTimeProvider`. `NtpClock`
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implements a `gst::Clock` that synchronizes its time to a remote NTPv4 server.
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A new clock is created with `NetClientClock::new` or
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`NtpClock::new`, which takes the address and port of the remote time
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provider along with a name and an initial time.
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This clock will poll the time provider and will update its calibration
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parameters based on the local and remote observations.
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The "round-trip" property limits the maximum round trip packets can take.
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Various parameters of the clock can be configured with the parent `gst::Clock`
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"timeout", "window-size" and "window-threshold" object properties.
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A `NetClientClock` and `NtpClock` is typically set on a `gst::Pipeline` with
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`gst::Pipeline::use_clock`.
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If you set a `gst::Bus` on the clock via the "bus" object property, it will
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send [`crate::gst::MessageType::Element`] (XXX: @-reference does not belong to NetClientClock!) messages with an attached `gst::Structure` containing
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statistics about clock accuracy and network traffic.
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# Implements
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[`trait@gst::ClockExt`], [`trait@gst::ObjectExt`], [`trait@glib::object::ObjectExt`]
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<!-- impl NetClientClock::fn new -->
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Create a new `NetClientClock` that will report the time
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provided by the `NetTimeProvider` on `remote_address` and
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`remote_port`.
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## `name`
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a name for the clock
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## `remote_address`
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the address or hostname of the remote clock provider
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## `remote_port`
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the port of the remote clock provider
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## `base_time`
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initial time of the clock
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# Returns
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a new `gst::Clock` that receives a time from the remote
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clock.
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<!-- struct NetTimeProvider -->
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This object exposes the time of a `gst::Clock` on the network.
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A `NetTimeProvider` is created with `NetTimeProvider::new` which
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takes a `gst::Clock`, an address and a port number as arguments.
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After creating the object, a client clock such as `NetClientClock` can
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query the exposed clock over the network for its values.
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The `NetTimeProvider` typically wraps the clock used by a `gst::Pipeline`.
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# Implements
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[`trait@gst::ObjectExt`], [`trait@glib::object::ObjectExt`]
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<!-- impl NetTimeProvider::fn new -->
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Allows network clients to get the current time of `clock`.
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## `clock`
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a `gst::Clock` to export over the network
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## `address`
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an address to bind on as a dotted quad
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(xxx.xxx.xxx.xxx), IPv6 address, or NULL to bind to all addresses
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## `port`
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a port to bind on, or 0 to let the kernel choose
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# Returns
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the new `NetTimeProvider`, or NULL on error
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<!-- struct NtpClock -->
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# Implements
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[`NetClientClockExt`](trait@crate::NetClientClockExt), [`trait@gst::ClockExt`], [`trait@gst::ObjectExt`], [`trait@glib::object::ObjectExt`]
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<!-- impl NtpClock::fn new -->
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Create a new `NtpClock` that will report the time provided by
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the NTPv4 server on `remote_address` and `remote_port`.
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## `name`
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a name for the clock
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## `remote_address`
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the address or hostname of the remote clock provider
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## `remote_port`
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the port of the remote clock provider
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## `base_time`
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initial time of the clock
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# Returns
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a new `gst::Clock` that receives a time from the remote
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clock.
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<!-- struct PtpClock -->
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GstPtpClock implements a PTP (IEEE1588:2008) ordinary clock in slave-only
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mode, that allows a GStreamer pipeline to synchronize to a PTP network
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clock in some specific domain.
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The PTP subsystem can be initialized with `gst_ptp_init`, which then starts
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a helper process to do the actual communication via the PTP ports. This is
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required as PTP listens on ports < 1024 and thus requires special
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privileges. Once this helper process is started, the main process will
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synchronize to all PTP domains that are detected on the selected
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interfaces.
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`PtpClock::new` then allows to create a GstClock that provides the PTP
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time from a master clock inside a specific PTP domain. This clock will only
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return valid timestamps once the timestamps in the PTP domain are known. To
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check this, you can use `gst::ClockExt::wait_for_sync`, the GstClock::synced
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signal and `gst::ClockExt::is_synced`.
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To gather statistics about the PTP clock synchronization,
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`gst_ptp_statistics_callback_add` can be used. This gives the application
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the possibility to collect all kinds of statistics from the clock
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synchronization.
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# Implements
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[`trait@gst::ClockExt`], [`trait@gst::ObjectExt`], [`trait@glib::object::ObjectExt`]
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<!-- impl PtpClock::fn new -->
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Creates a new PTP clock instance that exports the PTP time of the master
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clock in `domain`. This clock can be slaved to other clocks as needed.
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If `gst_ptp_init` was not called before, this will call `gst_ptp_init` with
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default parameters.
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This clock only returns valid timestamps after it received the first
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times from the PTP master clock on the network. Once this happens the
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GstPtpClock::internal-clock property will become non-NULL. You can
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check this with `gst::ClockExt::wait_for_sync`, the GstClock::synced signal and
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`gst::ClockExt::is_synced`.
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## `name`
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Name of the clock
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## `domain`
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PTP domain
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# Returns
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A new `gst::Clock`
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