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/*
* GStreamer AVTP Plugin
* Copyright (C) 2019 Intel Corporation
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later
* version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
/**
* plugin-avtp:
*
* ## Audio Video Transport Protocol (AVTP) Plugin
*
* The AVTP plugin implements typical Talker and Listener functionalities that
* can be leveraged by GStreamer-based applications in order to implement TSN
* audio/video applications.
*
* ### Dependencies
*
* The plugin uses libavtp to handle AVTP packetization. Libavtp source code can
* be found in https://github.com/AVnu/libavtp as well as instructions to build
* and install it.
*
* If libavtp isn't detected by configure, the plugin isn't built.
*
* ### The application/x-avtp mime type
*
* For valid AVTPDUs encapsulated in GstBuffers, we use the caps with mime type
* application/x-avtp.
*
* AVTP mime type is pretty simple and has no fields.
*
* ### PTP Clock
*
* The AVTP plugin elements require that GStreamer pipeline clock be in sync
* with the network generalized PTP clock (gPTP). Applications using the AVTP
* plugin elements can achieve that by using GstPtpClock as the pipeline clock.
*
* Note that GstPtpClock is a UDP slave only clock, meaning that some other
* endpoint needs to provide the gPTP master clock.
*
* One can use, on another endpoint on the network, Linuxptp project ptp4l
* daemon to provide a gPTP master clock on the network over UDP:
*
* $ ptp4l -i $IFNAME
*
* For further information check ptp4l(8).
*
* ### FQTSS Setup
*
* FQTSS (Forwarding and Queuing Enhancements for Time-Sensitive Streams) can be
* enabled on Linux with the help of the mqprio and cbs qdiscs provided by the
* Linux Traffic Control. Below we provide an example to configure those qdiscs
* in order to transmit a CVF H.264 stream 1280x720@30fps. For further
* information on how to configure these qdiscs check tc-mqprio(8) and
* tc-cbs(8) man pages.
*
* On the host that will run as AVTP Talker (pipeline that generates the video
* stream), run the following commands:
*
* Configure mpqrio qdisc (replace $HANDLE_ID by an unused handle ID):
*
* $ tc qdisc add dev $IFNAME parent root handle $HANDLE_ID mqprio \
* num_tc 3 map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
* queues 1@0 1@1 2@2 hw 0
*
* Configure cbs qdisc:
*
* $ tc qdisc replace dev $IFNAME parent $HANDLE_ID:1 cbs idleslope 27756 \
* sendslope -972244 hicredit 42 locredit -1499 offload 1
*
* No FQTSS configuration is required at the host running as AVTP Listener.
*
* ### Capabilities
*
* The `avtpsink` and `avtpsrc` elements open `AF_PACKET` sockets, which require
* `CAP_NET_RAW` capability. Therefore, applications must have that capability
* in order to successfully use this element. For instance, one can use:
*
* $ sudo setcap cap_net_raw+ep <application>
*
* Applications can drop this capability after the sockets are open, after
* `avtpsrc` or `avtpsink` elements transition to PAUSED state. See setcap(8)
* man page for more information.
*
* ### Elements configuration
*
* Each element has its own configuration properties, with some being common
* to several elements. Basic properties are:
*
* * streamid (avtpaafpay, avtpcvfpay, avtpaafdepay, avtpcvfdepay): Stream ID
* associated with the stream.
*
* * ifname (avtpsink, avtpsrc): Network interface used to send/receive
* AVTP packets.
*
* * dst-macaddr (avtpsink, avtpsrc): Destination MAC address for the stream.
*
* * priority (avtpsink): Priority used by the plugin to transmit AVTP
* traffic.
*
* * mtt (avtpaafpay, avtpcvfpay): Maximum Transit Time, in nanoseconds, as
* defined in AVTP spec.
*
* * tu (avtpaafpay, avtpcvfpay): Maximum Time Uncertainty, in nanoseconds, as
* defined in AVTP spec.
*
* * processing-deadline (avtpaafpay, avtpcvfpay, avtpsink): Maximum amount of
* time, in nanoseconds, that the pipeline is expected to process any
* buffer. This value should be in sync between the one used on the
* payloader and the sink, as this time is also taken into consideration to
* define the correct presentation time of the packets on the AVTP listener
* side. It should be as low as possible (zero if possible).
*
* * tstamp-mode (avtpaafpay): AAF timestamping mode, as defined in AVTP spec.
*
* * mtu (avtpcvfpay): Maximum Transmit Unit of the underlying network, used
* to determine when to fragment a CVF packet and how big it should be.
*
* Check each element documentation for more details.
*
*
* ### Running a sample pipeline
*
* The following pipelines assume a hypothetical `-k ptp` flag that forces the
* pipeline clock to be GstPtpClock. A real application would programmatically
* define GstPtpClock as the pipeline clock (see next section). It is also
* assumed that `gst-launch-1.0` has CAP_NET_RAW capability.
*
* On the AVTP talker, the following pipeline can be used to generate an H.264
* stream to be sent via network using AVTP:
*
* $ gst-launch-1.0 -k ptp videotestsrc is-live=true ! clockoverlay ! \
* x264enc ! avtpcvfpay processing-deadline=20000000 ! \
* avtpsink ifname=$IFNAME
*
* On the AVTP listener host, the following pipeline can be used to get the
* AVTP stream, depacketize it and show it on the screen:
*
* $ gst-launch-1.0 -k ptp avtpsrc ifname=$IFNAME ! avtpcvfdepay ! \
* vaapih264dec ! videoconvert ! clockoverlay halignment=right ! \
* queue ! autovideosink
*
* ### Pipeline clock
*
* The AVTP plugin elements require that the pipeline clock is in sync with
* the network PTP clock. As GStreamer has a GstPtpClock, using it should be
* the simplest way of achieving that.
*
* However, as there's no way of forcing a clock to a pipeline using
* gst-launch-1.0 application, even for quick tests, it's necessary to have
* an application. One can refer to GStreamer "hello world" application,
* remembering to set the pipeline clock to GstPtpClock before putting the
* pipeline on "PLAYING" state. Some code like:
*
* GstClock *clk = gst_ptp_clock_new("ptp-clock", 0);
* gst_clock_wait_for_sync(clk, GST_CLOCK_TIME_NONE);
* gst_pipeline_use_clock (GST_PIPELINE (pipeline), clk);
*
* Would do the trick.
*
* ### Disclaimer
*
* It's out of scope for the AVTP plugin to verify how it is invoked, should
* a malicious software do it for Denial of Service attempts, or other
* compromises attempts.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <gst/gst.h>
#include "gstavtpaafdepay.h"
#include "gstavtpaafpay.h"
#include "gstavtpcvfdepay.h"
#include "gstavtpcvfpay.h"
#include "gstavtpsink.h"
#include "gstavtpsrc.h"
static gboolean
plugin_init (GstPlugin * plugin)
{
if (!gst_avtp_aaf_pay_plugin_init (plugin))
return FALSE;
if (!gst_avtp_aaf_depay_plugin_init (plugin))
return FALSE;
if (!gst_avtp_sink_plugin_init (plugin))
return FALSE;
if (!gst_avtp_src_plugin_init (plugin))
return FALSE;
if (!gst_avtp_cvf_pay_plugin_init (plugin))
return FALSE;
if (!gst_avtp_cvf_depay_plugin_init (plugin))
return FALSE;
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR,
avtp, "Audio/Video Transport Protocol (AVTP) plugin",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
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