54f38fcae5
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
74 lines
1.7 KiB
ReStructuredText
74 lines
1.7 KiB
ReStructuredText
.. 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_GET_STC:
|
|
|
|
===========
|
|
DMX_GET_STC
|
|
===========
|
|
|
|
Name
|
|
----
|
|
|
|
DMX_GET_STC
|
|
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
.. c:function:: int ioctl( int fd, DMX_GET_STC, struct dmx_stc *stc)
|
|
:name: DMX_GET_STC
|
|
|
|
Arguments
|
|
---------
|
|
|
|
``fd``
|
|
File descriptor returned by :c:func:`open() <dvb-dmx-open>`.
|
|
|
|
``stc``
|
|
Pointer to :c:type:`dmx_stc` where the stc data is to be stored.
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
This ioctl call returns the current value of the system time counter
|
|
(which is driven by a PES filter of type :c:type:`DMX_PES_PCR <dmx_ts_pes>`).
|
|
Some hardware supports more than one STC, so you must specify which one by
|
|
setting the :c:type:`num <dmx_stc>` field of stc before the ioctl (range 0...n).
|
|
The result is returned in form of a ratio with a 64 bit numerator
|
|
and a 32 bit denominator, so the real 90kHz STC value is
|
|
``stc->stc / stc->base``.
|
|
|
|
|
|
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
|
|
:widths: 1 16
|
|
|
|
- .. row 1
|
|
|
|
- ``EINVAL``
|
|
|
|
- Invalid stc number.
|
|
|
|
|
|
The generic error codes are described at the
|
|
:ref:`Generic Error Codes <gen-errors>` chapter.
|