.. -*- coding: utf-8; mode: rst -*-

.. _dmx_fopen:

================
DVB demux open()
================

Name
----

DVB demux open()


Synopsis
--------

.. c:function:: int open(const char *deviceName, int flags)
    :name: dvb-dmx-open

Arguments
---------

``name``
  Name of specific DVB 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)


Description
-----------

This system call, used with a device name of /dev/dvb/adapter0/demux0,
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/adapter0/dvr0 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/adapter0/demux0) 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.


Return Value
------------

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.