.. _vvas_xfunnel:

vvas_xfunnel
=============

The ``vvas_xfunnel`` VVAS Gstreamer plug-in serializes data on its sink pads by iterating through all of them in a round-robin fashion. If a sink pad has a buffer available, it sends the data on the source pad. If a sink pad does not have data available, the plug-in will wait for a user-configurable amount of time before moving on to the next sink pad.

When a new sink pad is added or removed from the ``vvas_xfunnel`` plug-in, it sends custom events to notify the ``vvas_xdefunnel`` plug-in to create or destroy source pads. Each buffer includes metadata that enables the ``vvas_xdefunnel`` plug-in to determine which source pad the buffer should be sent to.

The vvas_xfunnel plug-in can support a maximum of 256 sink pads connected to it.

``vvas_xfunnel`` supports all caps.

Refer ``vvas_xdefunnel`` plug-in which de-serializes these serialized data and pushes them to the output pads.

For ``vvas_xfunnel`` implementation details, refer to `vvas_xfunnel source code <https://github.com/Xilinx/VVAS/tree/master/vvas-gst-plugins/gst/funnel>`_

This plug-in supports:

* Multiple sink pads, single source pad.

* Sink pads are request pads and they can be added or removed dynamically.

* Serialization of parallel data using round robin algorithm.

.. important:: Caps of all the sink pads must be same, this is to avoid caps renegotiation always when sending buffer from the sink pad which has different caps.
.. important:: There are several custom events sent from this plugin for ``vvas_xdefunnel`` plug-in, intermediate plug-ins must pass these events.

Control Parameters and Plug-in Properties
------------------------------------------------

The following table lists the GStreamer plug-in properties supported by the vvas_xfunnel plug-in.

Table 1: vvas_xfunnel Plug-in Properties

+--------------------+-------------+---------------+--------------+-------------------------+
|                    |             |               |              |                         |
|  **Property Name** |   **Type**  |  **Range**    | **Default**  |   **Description**       |
|                    |             |               |              |                         |
+====================+=============+===============+==============+=========================+
|    queue-size      |   unsigned  |    1 - 100    |     2        | Buffer queue size       |
|                    |   integer   |               |              | for each sink pad       |
+--------------------+-------------+---------------+--------------+-------------------------+
| sink-wait-timeout  |   unsigned  |  1 - 4294967  |   4294967    | Time to wait before     |
|                    |   integer   |               |              | switching to next       |
|                    |             |               |              | sink pad in milli       |
|                    |             |               |              | seconds, When pipeline  |
|                    |             |               |              | is running in live      |
|                    |             |               |              | mode, sink-wait-timeout |
|                    |             |               |              | will be calculated as   |
|                    |             |               |              | 1/FPS, otherwise it     |
|                    |             |               |              | would be 4294967 ms,    |
|                    |             |               |              | user can overwrite      |
|                    |             |               |              | sink-wait-timeout       |
|                    |             |               |              | value in both the cases |
+--------------------+-------------+---------------+--------------+-------------------------+

Example Pipelines
-------------------------

.. code-block::

	gst-launch-1.0 -v \
	videotestsrc num-buffers=50 pattern=0  ! video/x-raw,format=NV12,width=640,height=480 ! funnel.sink_0 \
	videotestsrc num-buffers=80 pattern=19 ! video/x-raw,format=NV12,width=640,height=480 ! funnel.sink_1 \
	vvas_xfunnel name=funnel ! identity ! vvas_xdefunnel name=defunnel \
	defunnel.src_0 ! queue ! filesink location=sink_0.yuv \
	defunnel.src_1 ! queue ! filesink location=sink_1.yuv

..
  ------------
  MIT License

  Copyright (c) 2023 Advanced Micro Devices, Inc.

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  The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software.

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