mirror of https://gitee.com/openkylin/linux.git
65 lines
1.3 KiB
ReStructuredText
65 lines
1.3 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
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.. c:namespace:: DTV.dmx
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.. _DMX_GET_STC:
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===========
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DMX_GET_STC
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===========
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Name
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----
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DMX_GET_STC
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Synopsis
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--------
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.. c:macro:: DMX_GET_STC
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``int ioctl(int fd, DMX_GET_STC, struct dmx_stc *stc)``
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Arguments
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---------
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``fd``
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File descriptor returned by :c:func:`open()`.
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``stc``
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Pointer to :c:type:`dmx_stc` where the stc data is to be stored.
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Description
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-----------
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This ioctl call returns the current value of the system time counter
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(which is driven by a PES filter of type :c:type:`DMX_PES_PCR <dmx_ts_pes>`).
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Some hardware supports more than one STC, so you must specify which one by
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setting the :c:type:`num <dmx_stc>` field of stc before the ioctl (range 0...n).
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The result is returned in form of a ratio with a 64 bit numerator
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and a 32 bit denominator, so the real 90kHz STC value is
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``stc->stc / stc->base``.
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Return Value
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------------
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On success 0 is returned.
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On error -1 is returned, and the ``errno`` variable is set
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appropriately.
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.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 16
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- .. row 1
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- ``EINVAL``
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- Invalid stc number.
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The generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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