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The extended-controls.rst file had become too big. Split it up: each control class reference gets its own rst file, and this file just describes the Extended Control API. Each control class reference is also moved up one level into the table of contents to make it easier to find e.g. the codec control reference. Finally I rearranged the order so that all camera-related control classes are grouped together, ditto for codec/jpeg and fm-rx/tx. The ext-ctrls-codec.rst is still pretty big and it is a candidate to split up further in the future, possibly per codec. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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3.7 KiB
ReStructuredText
96 lines
3.7 KiB
ReStructuredText
.. Permission is granted to copy, distribute and/or modify this
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.. document under the terms of the GNU Free Documentation License,
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.. Version 1.1 or any later version published by the Free Software
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.. Foundation, with no Invariant Sections, no Front-Cover Texts
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.. and no Back-Cover Texts. A copy of the license is included at
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.. Documentation/media/uapi/fdl-appendix.rst.
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..
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.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
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.. _fm-rx-controls:
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*****************************
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FM Receiver Control Reference
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*****************************
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The FM Receiver (FM_RX) class includes controls for common features of
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FM Reception capable devices.
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.. _fm-rx-control-id:
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FM_RX Control IDs
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=================
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``V4L2_CID_FM_RX_CLASS (class)``
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The FM_RX class descriptor. Calling
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:ref:`VIDIOC_QUERYCTRL` for this control will
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return a description of this control class.
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``V4L2_CID_RDS_RECEPTION (boolean)``
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Enables/disables RDS reception by the radio tuner
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``V4L2_CID_RDS_RX_PTY (integer)``
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Gets RDS Programme Type field. This encodes up to 31 pre-defined
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programme types.
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``V4L2_CID_RDS_RX_PS_NAME (string)``
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Gets the Programme Service name (PS_NAME). It is intended for
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static display on a receiver. It is the primary aid to listeners in
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programme service identification and selection. In Annex E of
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:ref:`iec62106`, the RDS specification, there is a full
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description of the correct character encoding for Programme Service
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name strings. Also from RDS specification, PS is usually a single
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eight character text. However, it is also possible to find receivers
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which can scroll strings sized as 8 x N characters. So, this control
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must be configured with steps of 8 characters. The result is it must
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always contain a string with size multiple of 8.
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``V4L2_CID_RDS_RX_RADIO_TEXT (string)``
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Gets the Radio Text info. It is a textual description of what is
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being broadcasted. RDS Radio Text can be applied when broadcaster
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wishes to transmit longer PS names, programme-related information or
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any other text. In these cases, RadioText can be used in addition to
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``V4L2_CID_RDS_RX_PS_NAME``. The encoding for Radio Text strings is
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also fully described in Annex E of :ref:`iec62106`. The length of
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Radio Text strings depends on which RDS Block is being used to
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transmit it, either 32 (2A block) or 64 (2B block). However, it is
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also possible to find receivers which can scroll strings sized as 32
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x N or 64 x N characters. So, this control must be configured with
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steps of 32 or 64 characters. The result is it must always contain a
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string with size multiple of 32 or 64.
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``V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT (boolean)``
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If set, then a traffic announcement is in progress.
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``V4L2_CID_RDS_RX_TRAFFIC_PROGRAM (boolean)``
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If set, then the tuned programme carries traffic announcements.
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``V4L2_CID_RDS_RX_MUSIC_SPEECH (boolean)``
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If set, then this channel broadcasts music. If cleared, then it
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broadcasts speech. If the transmitter doesn't make this distinction,
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then it will be set.
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``V4L2_CID_TUNE_DEEMPHASIS``
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(enum)
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enum v4l2_deemphasis -
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Configures the de-emphasis value for reception. A de-emphasis filter
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is applied to the broadcast to accentuate the high audio
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frequencies. Depending on the region, a time constant of either 50
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or 75 useconds is used. The enum v4l2_deemphasis defines possible
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values for de-emphasis. Here they are:
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.. flat-table::
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:header-rows: 0
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:stub-columns: 0
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* - ``V4L2_DEEMPHASIS_DISABLED``
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- No de-emphasis is applied.
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* - ``V4L2_DEEMPHASIS_50_uS``
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- A de-emphasis of 50 uS is used.
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* - ``V4L2_DEEMPHASIS_75_uS``
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- A de-emphasis of 75 uS is used.
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