1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2.. c:namespace:: DTV.dmx 3 4.. _DMX_GET_STC: 5 6=========== 7DMX_GET_STC 8=========== 9 10Name 11---- 12 13DMX_GET_STC 14 15Synopsis 16-------- 17 18.. c:macro:: DMX_GET_STC 19 20``int ioctl(int fd, DMX_GET_STC, struct dmx_stc *stc)`` 21 22Arguments 23--------- 24 25``fd`` 26 File descriptor returned by :c:func:`open()`. 27 28``stc`` 29 Pointer to :c:type:`dmx_stc` where the stc data is to be stored. 30 31Description 32----------- 33 34This ioctl call returns the current value of the system time counter 35(which is driven by a PES filter of type :c:type:`DMX_PES_PCR <dmx_ts_pes>`). 36Some hardware supports more than one STC, so you must specify which one by 37setting the :c:type:`num <dmx_stc>` field of stc before the ioctl (range 0...n). 38The result is returned in form of a ratio with a 64 bit numerator 39and a 32 bit denominator, so the real 90kHz STC value is 40``stc->stc / stc->base``. 41 42Return Value 43------------ 44 45On success 0 is returned. 46 47On error -1 is returned, and the ``errno`` variable is set 48appropriately. 49 50.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| 51 52.. flat-table:: 53 :header-rows: 0 54 :stub-columns: 0 55 :widths: 1 16 56 57 - .. row 1 58 59 - ``EINVAL`` 60 61 - Invalid stc number. 62 63The generic error codes are described at the 64:ref:`Generic Error Codes <gen-errors>` chapter. 65