tegrakernel/kernel/kernel-4.9/Documentation/media/uapi/dvb/dmx-fopen.rst

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.. -*- 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
------------
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- ``ENODEV``
- Device driver not loaded/available.
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- ``EINVAL``
- Invalid argument.
- .. row 3
- ``EMFILE``
- “Too many open files”, i.e. no more filters available.
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- ``ENOMEM``
- The driver failed to allocate enough memory.