0001 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
0002 .. c:namespace:: DTV.dmx
0003
0004 .. _dmx_fwrite:
0005
0006 ========================
0007 Digital TV demux write()
0008 ========================
0009
0010 Name
0011 ----
0012
0013 Digital TV demux write()
0014
0015 Synopsis
0016 --------
0017
0018 .. c:function:: ssize_t write(int fd, const void *buf, size_t count)
0019
0020 Arguments
0021 ---------
0022
0023 ``fd``
0024 File descriptor returned by a previous call to :c:func:`open()`.
0025
0026 ``buf``
0027 Buffer with data to be written
0028
0029 ``count``
0030 Number of bytes at the buffer
0031
0032 Description
0033 -----------
0034
0035 This system call is only provided by the logical device
0036 ``/dev/dvb/adapter?/dvr?``, associated with the physical demux device that
0037 provides the actual DVR functionality. It is used for replay of a
0038 digitally recorded Transport Stream. Matching filters have to be defined
0039 in the corresponding physical demux device, ``/dev/dvb/adapter?/demux?``.
0040 The amount of data to be transferred is implied by count.
0041
0042 Return Value
0043 ------------
0044
0045 On success 0 is returned.
0046
0047 On error -1 is returned, and the ``errno`` variable is set
0048 appropriately.
0049
0050 .. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
0051
0052 .. flat-table::
0053 :header-rows: 0
0054 :stub-columns: 0
0055 :widths: 1 16
0056
0057 - - ``EWOULDBLOCK``
0058 - No data was written. This might happen if ``O_NONBLOCK`` was
0059 specified and there is no more buffer space available (if
0060 ``O_NONBLOCK`` is not specified the function will block until buffer
0061 space is available).
0062
0063 - - ``EBUSY``
0064 - This error code indicates that there are conflicting requests. The
0065 corresponding demux device is setup to receive data from the
0066 front- end. Make sure that these filters are stopped and that the
0067 filters with input set to ``DMX_IN_DVR`` are started.
0068
0069 The generic error codes are described at the
0070 :ref:`Generic Error Codes <gen-errors>` chapter.
