ptp: Initial implementation of a PTP clock

GstPtpClock implements a PTP (IEEE1588:2008) ordinary clock in
slave-only mode, that allows a GStreamer pipeline to synchronize
to a PTP network clock in some specific domain.

The PTP subsystem can be initialized with gst_ptp_init(), which then
starts a helper process to do the actual communication via the PTP
ports. This is required as PTP listens on ports < 1024 and thus
requires special privileges. Once this helper process is started, the
main process will synchronize to all PTP domains that are detected on
the selected interfaces.

gst_ptp_clock_new() then allows to create a GstClock that provides the
PTP time from a master clock inside a specific PTP domain. This clock
will only return valid timestamps once the timestamps in the PTP domain
are known. To check this, the GstPtpClock::internal-clock property and
the related notify::clock signal can be used. Once the internal clock
is not NULL, the PTP domain's time is known. Alternatively you can wait
for this with gst_ptp_clock_wait_ready().

To gather statistics about the PTP clock synchronization,
gst_ptp_statistics_callback_add() can be used. This gives the
application the possibility to collect all kinds of statistics
from the clock synchronization.

https://bugzilla.gnome.org/show_bug.cgi?id=749391

2 files changed, 27 insertions, 0 deletions

diff --git a/docs/libs/gstreamer-libs-docs.sgml b/docs/libs/gstreamer-libs-docs.sgml
index 0070771da..406d6064e 100644
--- a/docs/libs/gstreamer-libs-docs.sgml
+++ b/docs/libs/gstreamer-libs-docs.sgml
@@ -76,6 +76,7 @@
       <xi:include href="xml/gstnetclientclock.xml" />
       <xi:include href="xml/gstnettimepacket.xml" />
       <xi:include href="xml/gstnettimeprovider.xml" />
+      <xi:include href="xml/gstptpclock.xml" />
     </chapter>
 
     <chapter id="gstreamer-check">
diff --git a/docs/libs/gstreamer-libs-sections.txt b/docs/libs/gstreamer-libs-sections.txt
index f1db3a097..1dfc53b44 100644
--- a/docs/libs/gstreamer-libs-sections.txt
+++ b/docs/libs/gstreamer-libs-sections.txt
@@ -942,6 +942,32 @@ gst_net_time_provider_get_type
 </SECTION>
 
 <SECTION>
+<FILE>gstptpclock</FILE>
+<TITLE>GstPtpClock</TITLE>
+<INCLUDE>gst/net/net.h</INCLUDE>
+gst_ptp_init
+gst_ptp_deinit
+gst_ptp_is_initialized
+gst_ptp_is_supported
+
+GstPtpClock
+gst_ptp_clock_new
+
+gst_ptp_statistics_callback_add
+gst_ptp_statistics_callback_remove
+<SUBSECTION Standard>
+GstPtpClockClass
+GstPtpClockPrivate
+GST_PTP_CLOCK
+GST_IS_PTP_CLOCK
+GST_TYPE_PTP_CLOCK
+GST_PTP_CLOCK_CLASS
+GST_IS_PTP_CLOCK_CLASS
+<SUBSECTION Private>
+gst_ptp_clock_get_type
+</SECTION>
+
+<SECTION>
 <FILE>gstcheck</FILE>
 <TITLE>GstCheck</TITLE>
 <INCLUDE>gst/check/gstcheck.h</INCLUDE>