.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/userspace-api/media/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

.. _DMX_START:

=========
DMX_START
=========

Name
----

DMX_START


Synopsis
--------

.. c:function:: int ioctl( int fd, DMX_START)
    :name: DMX_START


Arguments
---------

``fd``
    File descriptor returned by :c:func:`open() <dvb-dmx-open>`.

Description
-----------

This ioctl call is used to start the actual filtering operation defined
via the ioctl calls :ref:`DMX_SET_FILTER` or :ref:`DMX_SET_PES_FILTER`.


Return Value
------------

On success 0 is returned.

On error -1 is returned, and the ``errno`` variable is set
appropriately.

.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|

.. flat-table::
    :header-rows:  0
    :stub-columns: 0


    -  .. row 1

       -  ``EINVAL``

       -  Invalid argument, i.e. no filtering parameters provided via the
	  :ref:`DMX_SET_FILTER` or :ref:`DMX_SET_PES_FILTER` ioctls.

    -  .. row 2

       -  ``EBUSY``

       -  This error code indicates that there are conflicting requests.
	  There are active filters filtering data from another input source.
	  Make sure that these filters are stopped before starting this
	  filter.


The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.