From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../userspace-api/media/v4l/dev-sliced-vbi.rst     | 661 +++++++++++++++++++++
 1 file changed, 661 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst

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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _sliced:
+
+*************************
+Sliced VBI Data Interface
+*************************
+
+VBI stands for Vertical Blanking Interval, a gap in the sequence of
+lines of an analog video signal. During VBI no picture information is
+transmitted, allowing some time while the electron beam of a cathode ray
+tube TV returns to the top of the screen.
+
+Sliced VBI devices use hardware to demodulate data transmitted in the
+VBI. V4L2 drivers shall *not* do this by software, see also the
+:ref:`raw VBI interface <raw-vbi>`. The data is passed as short
+packets of fixed size, covering one scan line each. The number of
+packets per video frame is variable.
+
+Sliced VBI capture and output devices are accessed through the same
+character special files as raw VBI devices. When a driver supports both
+interfaces, the default function of a ``/dev/vbi`` device is *raw* VBI
+capturing or output, and the sliced VBI function is only available after
+calling the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl as defined
+below. Likewise a ``/dev/video`` device may support the sliced VBI API,
+however the default function here is video capturing or output.
+Different file descriptors must be used to pass raw and sliced VBI data
+simultaneously, if this is supported by the driver.
+
+Querying Capabilities
+=====================
+
+Devices supporting the sliced VBI capturing or output API set the
+``V4L2_CAP_SLICED_VBI_CAPTURE`` or ``V4L2_CAP_SLICED_VBI_OUTPUT`` flag
+respectively, in the ``capabilities`` field of struct
+:c:type:`v4l2_capability` returned by the
+:ref:`VIDIOC_QUERYCAP` ioctl. At least one of the
+read/write or streaming :ref:`I/O methods <io>` must be
+supported. Sliced VBI devices may have a tuner or modulator.
+
+Supplemental Functions
+======================
+
+Sliced VBI devices shall support :ref:`video input or output <video>`
+and :ref:`tuner or modulator <tuner>` ioctls if they have these
+capabilities, and they may support :ref:`control` ioctls.
+The :ref:`video standard <standard>` ioctls provide information vital
+to program a sliced VBI device, therefore must be supported.
+
+.. _sliced-vbi-format-negotitation:
+
+Sliced VBI Format Negotiation
+=============================
+
+To find out which data services are supported by the hardware
+applications can call the
+:ref:`VIDIOC_G_SLICED_VBI_CAP <VIDIOC_G_SLICED_VBI_CAP>` ioctl.
+All drivers implementing the sliced VBI interface must support this
+ioctl. The results may differ from those of the
+:ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl when the number of VBI
+lines the hardware can capture or output per frame, or the number of
+services it can identify on a given line are limited. For example on PAL
+line 16 the hardware may be able to look for a VPS or Teletext signal,
+but not both at the same time.
+
+To determine the currently selected services applications set the
+``type`` field of struct :c:type:`v4l2_format` to
+``V4L2_BUF_TYPE_SLICED_VBI_CAPTURE`` or
+``V4L2_BUF_TYPE_SLICED_VBI_OUTPUT``, and the
+:ref:`VIDIOC_G_FMT <VIDIOC_G_FMT>` ioctl fills the ``fmt.sliced``
+member, a struct
+:c:type:`v4l2_sliced_vbi_format`.
+
+Applications can request different parameters by initializing or
+modifying the ``fmt.sliced`` member and calling the
+:ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl with a pointer to the
+struct :c:type:`v4l2_format` structure.
+
+The sliced VBI API is more complicated than the raw VBI API because the
+hardware must be told which VBI service to expect on each scan line. Not
+all services may be supported by the hardware on all lines (this is
+especially true for VBI output where Teletext is often unsupported and
+other services can only be inserted in one specific line). In many
+cases, however, it is sufficient to just set the ``service_set`` field
+to the required services and let the driver fill the ``service_lines``
+array according to hardware capabilities. Only if more precise control
+is needed should the programmer set the ``service_lines`` array
+explicitly.
+
+The :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl modifies the parameters
+according to hardware capabilities. When the driver allocates resources
+at this point, it may return an ``EBUSY`` error code if the required
+resources are temporarily unavailable. Other resource allocation points
+which may return ``EBUSY`` can be the
+:ref:`VIDIOC_STREAMON` ioctl and the first
+:c:func:`read()`, :c:func:`write()` and
+:c:func:`select()` call.
+
+.. c:type:: v4l2_sliced_vbi_format
+
+struct v4l2_sliced_vbi_format
+-----------------------------
+
+.. raw:: latex
+
+    \begingroup
+    \scriptsize
+    \setlength{\tabcolsep}{2pt}
+
+.. tabularcolumns:: |p{.85cm}|p{3.3cm}|p{4.45cm}|p{4.45cm}|p{4.45cm}|
+
+.. cssclass:: longtable
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 3 2 2 2
+
+    * - __u16
+      - ``service_set``
+      - :cspan:`2`
+
+	If ``service_set`` is non-zero when passed with
+	:ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` or
+	:ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>`, the ``service_lines``
+	array will be filled by the driver according to the services
+	specified in this field. For example, if ``service_set`` is
+	initialized with ``V4L2_SLICED_TELETEXT_B | V4L2_SLICED_WSS_625``,
+	a driver for the cx25840 video decoder sets lines 7-22 of both
+	fields [#f1]_ to ``V4L2_SLICED_TELETEXT_B`` and line 23 of the first
+	field to ``V4L2_SLICED_WSS_625``. If ``service_set`` is set to
+	zero, then the values of ``service_lines`` will be used instead.
+
+	On return the driver sets this field to the union of all elements
+	of the returned ``service_lines`` array. It may contain less
+	services than requested, perhaps just one, if the hardware cannot
+	handle more services simultaneously. It may be empty (zero) if
+	none of the requested services are supported by the hardware.
+    * - __u16
+      - ``service_lines``\ [2][24]
+      - :cspan:`2`
+
+	Applications initialize this array with sets of data services the
+	driver shall look for or insert on the respective scan line.
+	Subject to hardware capabilities drivers return the requested set,
+	a subset, which may be just a single service, or an empty set.
+	When the hardware cannot handle multiple services on the same line
+	the driver shall choose one. No assumptions can be made on which
+	service the driver chooses.
+
+	Data services are defined in :ref:`vbi-services2`. Array indices
+	map to ITU-R line numbers\ [#f2]_ as follows:
+    * -
+      -
+      - Element
+      - 525 line systems
+      - 625 line systems
+    * -
+      -
+      - ``service_lines``\ [0][1]
+      - 1
+      - 1
+    * -
+      -
+      - ``service_lines``\ [0][23]
+      - 23
+      - 23
+    * -
+      -
+      - ``service_lines``\ [1][1]
+      - 264
+      - 314
+    * -
+      -
+      - ``service_lines``\ [1][23]
+      - 286
+      - 336
+    * -
+      -
+      - :cspan:`2` Drivers must set ``service_lines`` [0][0] and
+	``service_lines``\ [1][0] to zero. The
+	``V4L2_VBI_ITU_525_F1_START``, ``V4L2_VBI_ITU_525_F2_START``,
+	``V4L2_VBI_ITU_625_F1_START`` and ``V4L2_VBI_ITU_625_F2_START``
+	defines give the start line numbers for each field for each 525 or
+	625 line format as a convenience. Don't forget that ITU line
+	numbering starts at 1, not 0.
+    * - __u32
+      - ``io_size``
+      - :cspan:`2` Maximum number of bytes passed by one
+	:c:func:`read()` or :c:func:`write()` call,
+	and the buffer size in bytes for the
+	:ref:`VIDIOC_QBUF` and
+	:ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl. Drivers set this field
+	to the size of struct
+	:c:type:`v4l2_sliced_vbi_data` times the
+	number of non-zero elements in the returned ``service_lines``
+	array (that is the number of lines potentially carrying data).
+    * - __u32
+      - ``reserved``\ [2]
+      - :cspan:`2` This array is reserved for future extensions.
+
+	Applications and drivers must set it to zero.
+
+.. raw:: latex
+
+    \endgroup
+
+.. _vbi-services2:
+
+Sliced VBI services
+-------------------
+
+.. raw:: latex
+
+    \footnotesize
+
+.. tabularcolumns:: |p{4.2cm}|p{1.1cm}|p{2.1cm}|p{2.0cm}|p{6.5cm}|
+
+.. flat-table::
+    :header-rows:  1
+    :stub-columns: 0
+    :widths:       2 1 1 2 2
+
+    * - Symbol
+      - Value
+      - Reference
+      - Lines, usually
+      - Payload
+    * - ``V4L2_SLICED_TELETEXT_B`` (Teletext System B)
+      - 0x0001
+      - :ref:`ets300706`,
+
+	:ref:`itu653`
+      - PAL/SECAM line 7-22, 320-335 (second field 7-22)
+      - Last 42 of the 45 byte Teletext packet, that is without clock
+	run-in and framing code, lsb first transmitted.
+    * - ``V4L2_SLICED_VPS``
+      - 0x0400
+      - :ref:`ets300231`
+      - PAL line 16
+      - Byte number 3 to 15 according to Figure 9 of ETS 300 231, lsb
+	first transmitted.
+    * - ``V4L2_SLICED_CAPTION_525``
+      - 0x1000
+      - :ref:`cea608`
+      - NTSC line 21, 284 (second field 21)
+      - Two bytes in transmission order, including parity bit, lsb first
+	transmitted.
+    * - ``V4L2_SLICED_WSS_625``
+      - 0x4000
+      - :ref:`itu1119`,
+
+	:ref:`en300294`
+      - PAL/SECAM line 23
+      -  See :ref:`v4l2-sliced-wss-625-payload` below.
+    * - ``V4L2_SLICED_VBI_525``
+      - 0x1000
+      - :cspan:`2` Set of services applicable to 525 line systems.
+    * - ``V4L2_SLICED_VBI_625``
+      - 0x4401
+      - :cspan:`2` Set of services applicable to 625 line systems.
+
+.. raw:: latex
+
+    \normalsize
+
+Drivers may return an ``EINVAL`` error code when applications attempt to
+read or write data without prior format negotiation, after switching the
+video standard (which may invalidate the negotiated VBI parameters) and
+after switching the video input (which may change the video standard as
+a side effect). The :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl may
+return an ``EBUSY`` error code when applications attempt to change the
+format while i/o is in progress (between a
+:ref:`VIDIOC_STREAMON` and
+:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` call, and after the first
+:c:func:`read()` or :c:func:`write()` call).
+
+.. _v4l2-sliced-wss-625-payload:
+
+V4L2_SLICED_WSS_625 payload
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The payload for ``V4L2_SLICED_WSS_625`` is:
+
+           +-----+------------------+-----------------------+
+	   |Byte |        0         |           1           |
+           +-----+--------+---------+-----------+-----------+
+	   |     | msb    | lsb     | msb       | lsb       |
+           |     +-+-+-+--+--+-+-+--+--+-+--+---+---+--+-+--+
+	   | Bit |7|6|5|4 | 3|2|1|0 | x|x|13|12 | 11|10|9|8 |
+           +-----+-+-+-+--+--+-+-+--+--+-+--+---+---+--+-+--+
+
+Reading and writing sliced VBI data
+===================================
+
+A single :c:func:`read()` or :c:func:`write()`
+call must pass all data belonging to one video frame. That is an array
+of struct :c:type:`v4l2_sliced_vbi_data` structures with one or
+more elements and a total size not exceeding ``io_size`` bytes. Likewise
+in streaming I/O mode one buffer of ``io_size`` bytes must contain data
+of one video frame. The ``id`` of unused
+struct :c:type:`v4l2_sliced_vbi_data` elements must be zero.
+
+.. c:type:: v4l2_sliced_vbi_data
+
+struct v4l2_sliced_vbi_data
+---------------------------
+
+.. tabularcolumns:: |p{1.2cm}|p{2.2cm}|p{13.9cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 4
+
+    * - __u32
+      - ``id``
+      - A flag from :ref:`vbi-services` identifying the type of data in
+	this packet. Only a single bit must be set. When the ``id`` of a
+	captured packet is zero, the packet is empty and the contents of
+	other fields are undefined. Applications shall ignore empty
+	packets. When the ``id`` of a packet for output is zero the
+	contents of the ``data`` field are undefined and the driver must
+	no longer insert data on the requested ``field`` and ``line``.
+    * - __u32
+      - ``field``
+      - The video field number this data has been captured from, or shall
+	be inserted at. ``0`` for the first field, ``1`` for the second
+	field.
+    * - __u32
+      - ``line``
+      - The field (as opposed to frame) line number this data has been
+	captured from, or shall be inserted at. See :ref:`vbi-525` and
+	:ref:`vbi-625` for valid values. Sliced VBI capture devices can
+	set the line number of all packets to ``0`` if the hardware cannot
+	reliably identify scan lines. The field number must always be
+	valid.
+    * - __u32
+      - ``reserved``
+      - This field is reserved for future extensions. Applications and
+	drivers must set it to zero.
+    * - __u8
+      - ``data``\ [48]
+      - The packet payload. See :ref:`vbi-services` for the contents and
+	number of bytes passed for each data type. The contents of padding
+	bytes at the end of this array are undefined, drivers and
+	applications shall ignore them.
+
+Packets are always passed in ascending line number order, without
+duplicate line numbers. The :c:func:`write()` function and
+the :ref:`VIDIOC_QBUF` ioctl must return an ``EINVAL``
+error code when applications violate this rule. They must also return an
+EINVAL error code when applications pass an incorrect field or line
+number, or a combination of ``field``, ``line`` and ``id`` which has not
+been negotiated with the :ref:`VIDIOC_G_FMT <VIDIOC_G_FMT>` or
+:ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl. When the line numbers are
+unknown the driver must pass the packets in transmitted order. The
+driver can insert empty packets with ``id`` set to zero anywhere in the
+packet array.
+
+To assure synchronization and to distinguish from frame dropping, when a
+captured frame does not carry any of the requested data services drivers
+must pass one or more empty packets. When an application fails to pass
+VBI data in time for output, the driver must output the last VPS and WSS
+packet again, and disable the output of Closed Caption and Teletext
+data, or output data which is ignored by Closed Caption and Teletext
+decoders.
+
+A sliced VBI device may support :ref:`read/write <rw>` and/or
+streaming (:ref:`memory mapping <mmap>` and/or
+:ref:`user pointer <userp>`) I/O. The latter bears the possibility of
+synchronizing video and VBI data by using buffer timestamps.
+
+Sliced VBI Data in MPEG Streams
+===============================
+
+If a device can produce an MPEG output stream, it may be capable of
+providing
+:ref:`negotiated sliced VBI services <sliced-vbi-format-negotitation>`
+as data embedded in the MPEG stream. Users or applications control this
+sliced VBI data insertion with the
+:ref:`V4L2_CID_MPEG_STREAM_VBI_FMT <v4l2-mpeg-stream-vbi-fmt>`
+control.
+
+If the driver does not provide the
+:ref:`V4L2_CID_MPEG_STREAM_VBI_FMT <v4l2-mpeg-stream-vbi-fmt>`
+control, or only allows that control to be set to
+:ref:`V4L2_MPEG_STREAM_VBI_FMT_NONE <v4l2-mpeg-stream-vbi-fmt>`,
+then the device cannot embed sliced VBI data in the MPEG stream.
+
+The
+:ref:`V4L2_CID_MPEG_STREAM_VBI_FMT <v4l2-mpeg-stream-vbi-fmt>`
+control does not implicitly set the device driver to capture nor cease
+capturing sliced VBI data. The control only indicates to embed sliced
+VBI data in the MPEG stream, if an application has negotiated sliced VBI
+service be captured.
+
+It may also be the case that a device can embed sliced VBI data in only
+certain types of MPEG streams: for example in an MPEG-2 PS but not an
+MPEG-2 TS. In this situation, if sliced VBI data insertion is requested,
+the sliced VBI data will be embedded in MPEG stream types when
+supported, and silently omitted from MPEG stream types where sliced VBI
+data insertion is not supported by the device.
+
+The following subsections specify the format of the embedded sliced VBI
+data.
+
+MPEG Stream Embedded, Sliced VBI Data Format: NONE
+--------------------------------------------------
+
+The
+:ref:`V4L2_MPEG_STREAM_VBI_FMT_NONE <v4l2-mpeg-stream-vbi-fmt>`
+embedded sliced VBI format shall be interpreted by drivers as a control
+to cease embedding sliced VBI data in MPEG streams. Neither the device
+nor driver shall insert "empty" embedded sliced VBI data packets in the
+MPEG stream when this format is set. No MPEG stream data structures are
+specified for this format.
+
+MPEG Stream Embedded, Sliced VBI Data Format: IVTV
+--------------------------------------------------
+
+The
+:ref:`V4L2_MPEG_STREAM_VBI_FMT_IVTV <v4l2-mpeg-stream-vbi-fmt>`
+embedded sliced VBI format, when supported, indicates to the driver to
+embed up to 36 lines of sliced VBI data per frame in an MPEG-2 *Private
+Stream 1 PES* packet encapsulated in an MPEG-2 *Program Pack* in the
+MPEG stream.
+
+*Historical context*: This format specification originates from a
+custom, embedded, sliced VBI data format used by the ``ivtv`` driver.
+This format has already been informally specified in the kernel sources
+in the file ``Documentation/userspace-api/media/drivers/cx2341x-uapi.rst`` . The
+maximum size of the payload and other aspects of this format are driven
+by the CX23415 MPEG decoder's capabilities and limitations with respect
+to extracting, decoding, and displaying sliced VBI data embedded within
+an MPEG stream.
+
+This format's use is *not* exclusive to the ``ivtv`` driver *nor*
+exclusive to CX2341x devices, as the sliced VBI data packet insertion
+into the MPEG stream is implemented in driver software. At least the
+``cx18`` driver provides sliced VBI data insertion into an MPEG-2 PS in
+this format as well.
+
+The following definitions specify the payload of the MPEG-2 *Private
+Stream 1 PES* packets that contain sliced VBI data when
+:ref:`V4L2_MPEG_STREAM_VBI_FMT_IVTV <v4l2-mpeg-stream-vbi-fmt>`
+is set. (The MPEG-2 *Private Stream 1 PES* packet header and
+encapsulating MPEG-2 *Program Pack* header are not detailed here. Please
+refer to the MPEG-2 specifications for details on those packet headers.)
+
+The payload of the MPEG-2 *Private Stream 1 PES* packets that contain
+sliced VBI data is specified by struct
+:c:type:`v4l2_mpeg_vbi_fmt_ivtv`. The
+payload is variable length, depending on the actual number of lines of
+sliced VBI data present in a video frame. The payload may be padded at
+the end with unspecified fill bytes to align the end of the payload to a
+4-byte boundary. The payload shall never exceed 1552 bytes (2 fields
+with 18 lines/field with 43 bytes of data/line and a 4 byte magic
+number).
+
+.. c:type:: v4l2_mpeg_vbi_fmt_ivtv
+
+struct v4l2_mpeg_vbi_fmt_ivtv
+-----------------------------
+
+.. tabularcolumns:: |p{4.2cm}|p{2.0cm}|p{11.1cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u8
+      - ``magic``\ [4]
+      - A "magic" constant from :ref:`v4l2-mpeg-vbi-fmt-ivtv-magic` that
+	indicates this is a valid sliced VBI data payload and also
+	indicates which member of the anonymous union, ``itv0`` or
+	``ITV0``, to use for the payload data.
+    * - union {
+      - (anonymous)
+    * - struct :c:type:`v4l2_mpeg_vbi_itv0`
+      - ``itv0``
+      - The primary form of the sliced VBI data payload that contains
+	anywhere from 1 to 35 lines of sliced VBI data. Line masks are
+	provided in this form of the payload indicating which VBI lines
+	are provided.
+    * - struct :ref:`v4l2_mpeg_vbi_ITV0 <v4l2-mpeg-vbi-itv0-1>`
+      - ``ITV0``
+      - An alternate form of the sliced VBI data payload used when 36
+	lines of sliced VBI data are present. No line masks are provided
+	in this form of the payload; all valid line mask bits are
+	implcitly set.
+    * - }
+      -
+
+.. _v4l2-mpeg-vbi-fmt-ivtv-magic:
+
+Magic Constants for struct v4l2_mpeg_vbi_fmt_ivtv magic field
+-------------------------------------------------------------
+
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.5cm}|
+
+.. flat-table::
+    :header-rows:  1
+    :stub-columns: 0
+    :widths:       3 1 4
+
+    * - Defined Symbol
+      - Value
+      - Description
+    * - ``V4L2_MPEG_VBI_IVTV_MAGIC0``
+      - "itv0"
+      - Indicates the ``itv0`` member of the union in struct
+	:c:type:`v4l2_mpeg_vbi_fmt_ivtv` is
+	valid.
+    * - ``V4L2_MPEG_VBI_IVTV_MAGIC1``
+      - "ITV0"
+      - Indicates the ``ITV0`` member of the union in struct
+	:c:type:`v4l2_mpeg_vbi_fmt_ivtv` is
+	valid and that 36 lines of sliced VBI data are present.
+
+
+.. c:type:: v4l2_mpeg_vbi_itv0
+
+.. c:type:: v4l2_mpeg_vbi_ITV0
+
+structs v4l2_mpeg_vbi_itv0 and v4l2_mpeg_vbi_ITV0
+-------------------------------------------------
+
+.. raw:: latex
+
+   \footnotesize
+
+.. tabularcolumns:: |p{4.6cm}|p{2.0cm}|p{10.7cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __le32
+      - ``linemask``\ [2]
+      - Bitmasks indicating the VBI service lines present. These
+	``linemask`` values are stored in little endian byte order in the
+	MPEG stream. Some reference ``linemask`` bit positions with their
+	corresponding VBI line number and video field are given below.
+	b\ :sub:`0` indicates the least significant bit of a ``linemask``
+	value:
+
+
+	::
+
+	    linemask[0] b0:     line  6  first field
+	    linemask[0] b17:    line 23  first field
+	    linemask[0] b18:    line  6  second field
+	    linemask[0] b31:    line 19  second field
+	    linemask[1] b0:     line 20  second field
+	    linemask[1] b3:     line 23  second field
+	    linemask[1] b4-b31: unused and set to 0
+    * - struct
+	:c:type:`v4l2_mpeg_vbi_itv0_line`
+      - ``line``\ [35]
+      - This is a variable length array that holds from 1 to 35 lines of
+	sliced VBI data. The sliced VBI data lines present correspond to
+	the bits set in the ``linemask`` array, starting from b\ :sub:`0`
+	of ``linemask``\ [0] up through b\ :sub:`31` of ``linemask``\ [0],
+	and from b\ :sub:`0` of ``linemask``\ [1] up through b\ :sub:`3` of
+	``linemask``\ [1]. ``line``\ [0] corresponds to the first bit
+	found set in the ``linemask`` array, ``line``\ [1] corresponds to
+	the second bit found set in the ``linemask`` array, etc. If no
+	``linemask`` array bits are set, then ``line``\ [0] may contain
+	one line of unspecified data that should be ignored by
+	applications.
+
+.. raw:: latex
+
+   \normalsize
+
+.. _v4l2-mpeg-vbi-itv0-1:
+
+struct v4l2_mpeg_vbi_ITV0
+-------------------------
+
+.. tabularcolumns:: |p{5.2cm}|p{2.4cm}|p{9.7cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - struct
+	:c:type:`v4l2_mpeg_vbi_itv0_line`
+      - ``line``\ [36]
+      - A fixed length array of 36 lines of sliced VBI data. ``line``\ [0]
+	through ``line``\ [17] correspond to lines 6 through 23 of the
+	first field. ``line``\ [18] through ``line``\ [35] corresponds to
+	lines 6 through 23 of the second field.
+
+
+.. c:type:: v4l2_mpeg_vbi_itv0_line
+
+struct v4l2_mpeg_vbi_itv0_line
+------------------------------
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u8
+      - ``id``
+      - A line identifier value from
+	:ref:`ITV0-Line-Identifier-Constants` that indicates the type of
+	sliced VBI data stored on this line.
+    * - __u8
+      - ``data``\ [42]
+      - The sliced VBI data for the line.
+
+
+.. _ITV0-Line-Identifier-Constants:
+
+Line Identifiers for struct v4l2_mpeg_vbi_itv0_line id field
+------------------------------------------------------------
+
+.. tabularcolumns:: |p{7.0cm}|p{1.8cm}|p{8.5cm}|
+
+.. flat-table::
+    :header-rows:  1
+    :stub-columns: 0
+    :widths:       3 1 4
+
+    * - Defined Symbol
+      - Value
+      - Description
+    * - ``V4L2_MPEG_VBI_IVTV_TELETEXT_B``
+      - 1
+      - Refer to :ref:`Sliced VBI services <vbi-services2>` for a
+	description of the line payload.
+    * - ``V4L2_MPEG_VBI_IVTV_CAPTION_525``
+      - 4
+      - Refer to :ref:`Sliced VBI services <vbi-services2>` for a
+	description of the line payload.
+    * - ``V4L2_MPEG_VBI_IVTV_WSS_625``
+      - 5
+      - Refer to :ref:`Sliced VBI services <vbi-services2>` for a
+	description of the line payload.
+    * - ``V4L2_MPEG_VBI_IVTV_VPS``
+      - 7
+      - Refer to :ref:`Sliced VBI services <vbi-services2>` for a
+	description of the line payload.
+
+
+.. [#f1]
+   According to :ref:`ETS 300 706 <ets300706>` lines 6-22 of the first
+   field and lines 5-22 of the second field may carry Teletext data.
+
+.. [#f2]
+   See also :ref:`vbi-525` and :ref:`vbi-625`.
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