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media: dvb uAPI docs: minor editorial changes
Do minor editorial changes to improve documentation readability: - mark literals as such; - add table markups to hint sizes; - define what PES means; - instead of hardcoding devnode numbers to zero (like adapter0/) use a question mark, to indicate that multiple devnodes may exist; - add cross-references where useful. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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@ -28,20 +28,20 @@ Arguments
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``flags``
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A bit-wise OR of the following flags:
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.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 16
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-
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- O_RDONLY
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- - ``O_RDONLY``
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- read-only access
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-
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- O_RDWR
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- - ``O_RDWR``
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- read/write access
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-
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- O_NONBLOCK
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- - ``O_NONBLOCK``
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- open in non-blocking mode
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(blocking mode is the default)
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@ -52,15 +52,16 @@ Description
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This system call opens a named ca device (e.g. ``/dev/dvb/adapter?/ca?``)
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for subsequent use.
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When an open() call has succeeded, the device will be ready for use. The
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When an ``open()`` call has succeeded, the device will be ready for use. The
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significance of blocking or non-blocking mode is described in the
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documentation for functions where there is a difference. It does not
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affect the semantics of the open() call itself. A device opened in
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affect the semantics of the ``open()`` call itself. A device opened in
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blocking mode can later be put into non-blocking mode (and vice versa)
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using the F_SETFL command of the fcntl system call. This is a standard
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system call, documented in the Linux manual page for fcntl. Only one
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user can open the CA Device in O_RDWR mode. All other attempts to open
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the device in this mode will fail, and an error code will be returned.
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using the ``F_SETFL`` command of the ``fcntl`` system call. This is a
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standard system call, documented in the Linux manual page for fcntl.
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Only one user can open the CA Device in ``O_RDWR`` mode. All other
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attempts to open the device in this mode will fail, and an error code
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will be returned.
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Return Value
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@ -33,8 +33,8 @@ Description
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-----------
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This ioctl call allows to add multiple PIDs to a transport stream filter
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previously set up with DMX_SET_PES_FILTER and output equal to
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DMX_OUT_TSDEMUX_TAP.
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previously set up with :ref:`DMX_SET_PES_FILTER` and output equal to
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:c:type:`DMX_OUT_TSDEMUX_TAP <dmx_output>`.
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Return Value
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@ -23,13 +23,14 @@ Arguments
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---------
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``fd``
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File descriptor returned by a previous call to :c:func:`open() <dvb-ca-open>`.
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File descriptor returned by a previous call to
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:c:func:`open() <dvb-dmx-open>`.
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Description
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-----------
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This system call deactivates and deallocates a filter that was
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previously allocated via the open() call.
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previously allocated via the :c:func:`open() <dvb-dmx-open>` call.
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Return Value
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@ -27,20 +27,23 @@ Arguments
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``flags``
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A bit-wise OR of the following flags:
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.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 16
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-
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- O_RDONLY
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- ``O_RDONLY``
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- read-only access
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-
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- O_RDWR
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- ``O_RDWR``
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- read/write access
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-
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- O_NONBLOCK
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- ``O_NONBLOCK``
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- open in non-blocking mode
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(blocking mode is the default)
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@ -48,22 +51,22 @@ Arguments
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Description
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-----------
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This system call, used with a device name of /dev/dvb/adapter0/demux0,
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This system call, used with a device name of ``/dev/dvb/adapter?/demux?``,
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allocates a new filter and returns a handle which can be used for
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subsequent control of that filter. This call has to be made for each
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filter to be used, i.e. every returned file descriptor is a reference to
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a single filter. /dev/dvb/adapter0/dvr0 is a logical device to be used
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a single filter. ``/dev/dvb/adapter?/dvr?`` is a logical device to be used
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for retrieving Transport Streams for digital video recording. When
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reading from this device a transport stream containing the packets from
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all PES filters set in the corresponding demux device
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(/dev/dvb/adapter0/demux0) having the output set to DMX_OUT_TS_TAP. A
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recorded Transport Stream is replayed by writing to this device.
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(``/dev/dvb/adapter?/demux?``) having the output set to ``DMX_OUT_TS_TAP``.
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A recorded Transport Stream is replayed by writing to this device.
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The significance of blocking or non-blocking mode is described in the
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documentation for functions where there is a difference. It does not
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affect the semantics of the open() call itself. A device opened in
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blocking mode can later be put into non-blocking mode (and vice versa)
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using the F_SETFL command of the fcntl system call.
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affect the semantics of the ``open()`` call itself. A device opened
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in blocking mode can later be put into non-blocking mode (and vice versa)
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using the ``F_SETFL`` command of the fcntl system call.
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Return Value
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@ -33,10 +33,10 @@ Arguments
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Description
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-----------
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This system call returns filtered data, which might be section or PES
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data. The filtered data is transferred from the driver’s internal
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circular buffer to buf. The maximum amount of data to be transferred is
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implied by count.
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This system call returns filtered data, which might be section or Packetized
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Elementary Stream (PES) data. The filtered data is transferred from
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the driver’s internal circular buffer to ``buf``. The maximum amount of data
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to be transferred is implied by count.
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.. note::
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@ -34,10 +34,10 @@ Description
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-----------
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This system call is only provided by the logical device
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/dev/dvb/adapter0/dvr0, associated with the physical demux device that
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``/dev/dvb/adapter?/dvr?``, associated with the physical demux device that
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provides the actual DVR functionality. It is used for replay of a
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digitally recorded Transport Stream. Matching filters have to be defined
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in the corresponding physical demux device, /dev/dvb/adapter0/demux0.
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in the corresponding physical demux device, ``/dev/dvb/adapter?/demux?``.
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The amount of data to be transferred is implied by count.
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@ -25,18 +25,19 @@ Arguments
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File descriptor returned by :c:func:`open() <dvb-dmx-open>`.
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``stc``
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Pointer to the location where the stc is to be stored.
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Pointer to :c:type:`dmx_stc` where the stc data is to be stored.
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Description
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-----------
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This ioctl call returns the current value of the system time counter
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(which is driven by a PES filter of type DMX_PES_PCR). Some hardware
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supports more than one STC, so you must specify which one by setting the
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num field of stc before the ioctl (range 0...n). The result is returned
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in form of a ratio with a 64 bit numerator and a 32 bit denominator, so
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the real 90kHz STC value is stc->stc / stc->base .
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(which is driven by a PES filter of type :c:type:`DMX_PES_PCR <dmx_ts_pes>`).
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Some hardware supports more than one STC, so you must specify which one by
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setting the :c:type:`num <dmx_stc>` field of stc before the ioctl (range 0...n).
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The result is returned in form of a ratio with a 64 bit numerator
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and a 32 bit denominator, so the real 90kHz STC value is
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``stc->stc / stc->base``.
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Return Value
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@ -34,8 +34,8 @@ Description
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This ioctl call allows to remove a PID when multiple PIDs are set on a
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transport stream filter, e. g. a filter previously set up with output
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equal to DMX_OUT_TSDEMUX_TAP, created via either
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DMX_SET_PES_FILTER or DMX_ADD_PID.
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equal to :c:type:`DMX_OUT_TSDEMUX_TAP <dmx_output>`, created via either
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:ref:`DMX_SET_PES_FILTER` or :ref:`DMX_ADD_PID`.
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Return Value
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@ -33,7 +33,7 @@ Description
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This ioctl call is used to set the size of the circular buffer used for
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filtered data. The default size is two maximum sized sections, i.e. if
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this function is not called a buffer size of 2 \* 4096 bytes will be
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this function is not called a buffer size of ``2 * 4096`` bytes will be
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used.
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@ -40,8 +40,8 @@ state whether a section should be CRC-checked, whether the filter should
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be a ”one-shot” filter, i.e. if the filtering operation should be
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stopped after the first section is received, and whether the filtering
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operation should be started immediately (without waiting for a
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DMX_START ioctl call). If a filter was previously set-up, this filter
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will be canceled, and the receive buffer will be flushed.
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:ref:`DMX_START` ioctl call). If a filter was previously set-up, this
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filter will be canceled, and the receive buffer will be flushed.
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Return Value
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@ -29,8 +29,8 @@ Description
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-----------
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This ioctl call is used to stop the actual filtering operation defined
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via the ioctl calls DMX_SET_FILTER or DMX_SET_PES_FILTER and
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started via the DMX_START command.
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via the ioctl calls :ref:`DMX_SET_FILTER` or :ref:`DMX_SET_PES_FILTER` and
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started via the :ref:`DMX_START` command.
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Return Value
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@ -20,6 +20,6 @@ Signal statistics are provided via
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.. note::
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Most statistics require the demodulator to be fully locked
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(e. g. with FE_HAS_LOCK bit set). See
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(e. g. with :c:type:`FE_HAS_LOCK <fe_status>` bit set). See
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:ref:`Frontend statistics indicators <frontend-stat-properties>` for
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more details.
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@ -33,7 +33,8 @@ Arguments
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Description
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===========
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Sends the DiSEqC command pointed by ``argp`` to the antenna subsystem.
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Sends the DiSEqC command pointed by :c:type:`dvb_diseqc_master_cmd`
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to the antenna subsystem.
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Return Value
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============
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Description
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===========
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All Digital TV frontend devices support the ``FE_GET_INFO`` ioctl. It is used
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to identify kernel devices compatible with this specification and to
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All Digital TV frontend devices support the :ref:`FE_GET_INFO` ioctl. It is
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used to identify kernel devices compatible with this specification and to
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obtain information about driver and hardware capabilities. The ioctl
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takes a pointer to dvb_frontend_info which is filled by the driver.
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When the driver is not compatible with this specification the ioctl
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@ -30,7 +30,7 @@ Arguments
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- 0 - normal tune mode
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- FE_TUNE_MODE_ONESHOT - When set, this flag will disable any
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- ``FE_TUNE_MODE_ONESHOT`` - When set, this flag will disable any
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zigzagging or other "normal" tuning behaviour. Additionally,
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there will be no automatic monitoring of the lock status, and
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hence no frontend events will be generated. If a frontend device
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@ -42,7 +42,7 @@ Description
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===========
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Allow setting tuner mode flags to the frontend, between 0 (normal) or
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FE_TUNE_MODE_ONESHOT mode
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``FE_TUNE_MODE_ONESHOT`` mode
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Return Value
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@ -78,7 +78,7 @@ parameter.
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In the old days, struct :c:type:`dvb_frontend_info`
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used to contain ``fe_type_t`` field to indicate the delivery systems,
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filled with either FE_QPSK, FE_QAM, FE_OFDM or FE_ATSC. While this
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filled with either ``FE_QPSK, FE_QAM, FE_OFDM`` or ``FE_ATSC``. While this
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is still filled to keep backward compatibility, the usage of this field
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is deprecated, as it can report just one delivery system, but some
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devices support multiple delivery systems. Please use
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