Documentation/userspace-api/media/dvb/dmx-fopen.rst
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: DTV.dmx
.. _dmx_fopen:
Digital TV demux open()
.. c:function:: int open(const char *deviceName, int flags)
name
Name of specific Digital TV demux device.
flags
A bit-wise OR of the following flags:
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-
- ``O_RDONLY``
- read-only access
-
- ``O_RDWR``
- read/write access
-
- ``O_NONBLOCK``
- open in non-blocking mode
(blocking mode is the default)
This system call, used with a device name of /dev/dvb/adapter?/demux?,
allocates a new filter and returns a handle which can be used for
subsequent control of that filter. This call has to be made for each
filter to be used, i.e. every returned file descriptor is a reference to
a single filter. /dev/dvb/adapter?/dvr? is a logical device to be used
for retrieving Transport Streams for digital video recording. When
reading from this device a transport stream containing the packets from
all PES filters set in the corresponding demux device
(/dev/dvb/adapter?/demux?) having the output set to DMX_OUT_TS_TAP.
A recorded Transport Stream is replayed by writing to this device.
The significance of blocking or non-blocking mode is described in the
documentation for functions where there is a difference. It does not
affect the semantics of the open() call itself. A device opened
in blocking mode can later be put into non-blocking mode (and vice versa)
using the F_SETFL command of the fcntl system call.
On success 0 is returned.
On error -1 is returned, and the errno variable is set
appropriately.
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- - ``EMFILE``
- "Too many open files", i.e. no more filters available.
The generic error codes are described at the
:ref:Generic Error Codes <gen-errors> chapter.