203 lines · plain
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later2.. c:namespace:: V4L3 4.. _VIDIOC_G_SLICED_VBI_CAP:5 6*****************************7ioctl VIDIOC_G_SLICED_VBI_CAP8*****************************9 10Name11====12 13VIDIOC_G_SLICED_VBI_CAP - Query sliced VBI capabilities14 15Synopsis16========17 18.. c:macro:: VIDIOC_G_SLICED_VBI_CAP19 20``int ioctl(int fd, VIDIOC_G_SLICED_VBI_CAP, struct v4l2_sliced_vbi_cap *argp)``21 22Arguments23=========24 25``fd``26 File descriptor returned by :c:func:`open()`.27 28``argp``29 Pointer to struct :c:type:`v4l2_sliced_vbi_cap`.30 31Description32===========33 34To find out which data services are supported by a sliced VBI capture or35output device, applications initialize the ``type`` field of a struct36:c:type:`v4l2_sliced_vbi_cap`, clear the37``reserved`` array and call the :ref:`VIDIOC_G_SLICED_VBI_CAP <VIDIOC_G_SLICED_VBI_CAP>` ioctl. The38driver fills in the remaining fields or returns an ``EINVAL`` error code if39the sliced VBI API is unsupported or ``type`` is invalid.40 41.. note::42 43 The ``type`` field was added, and the ioctl changed from read-only44 to write-read, in Linux 2.6.19.45 46.. c:type:: v4l2_sliced_vbi_cap47 48.. tabularcolumns:: |p{1.4cm}|p{4.4cm}|p{4.5cm}|p{3.6cm}|p{3.6cm}|49 50.. flat-table:: struct v4l2_sliced_vbi_cap51 :header-rows: 052 :stub-columns: 053 :widths: 3 3 2 2 254 55 * - __u1656 - ``service_set``57 - :cspan:`2` A set of all data services supported by the driver.58 59 Equal to the union of all elements of the ``service_lines`` array.60 * - __u1661 - ``service_lines``\ [2][24]62 - :cspan:`2` Each element of this array contains a set of data63 services the hardware can look for or insert into a particular64 scan line. Data services are defined in :ref:`vbi-services`.65 Array indices map to ITU-R line numbers\ [#f1]_ as follows:66 * -67 -68 - Element69 - 525 line systems70 - 625 line systems71 * -72 -73 - ``service_lines``\ [0][1]74 - 175 - 176 * -77 -78 - ``service_lines``\ [0][23]79 - 2380 - 2381 * -82 -83 - ``service_lines``\ [1][1]84 - 26485 - 31486 * -87 -88 - ``service_lines``\ [1][23]89 - 28690 - 33691 * -92 * -93 -94 - :cspan:`2` The number of VBI lines the hardware can capture or95 output per frame, or the number of services it can identify on a96 given line may be limited. For example on PAL line 16 the hardware97 may be able to look for a VPS or Teletext signal, but not both at98 the same time. Applications can learn about these limits using the99 :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl as described in100 :ref:`sliced`.101 * -102 * -103 -104 - :cspan:`2` Drivers must set ``service_lines`` [0][0] and105 ``service_lines``\ [1][0] to zero.106 * - __u32107 - ``type``108 - Type of the data stream, see :c:type:`v4l2_buf_type`. Should be109 ``V4L2_BUF_TYPE_SLICED_VBI_CAPTURE`` or110 ``V4L2_BUF_TYPE_SLICED_VBI_OUTPUT``.111 * - __u32112 - ``reserved``\ [3]113 - :cspan:`2` This array is reserved for future extensions.114 115 Applications and drivers must set it to zero.116 117.. [#f1]118 119 See also :ref:`vbi-525` and :ref:`vbi-625`.120 121.. raw:: latex122 123 \scriptsize124 125.. tabularcolumns:: |p{3.9cm}|p{1.0cm}|p{2.0cm}|p{3.0cm}|p{7.0cm}|126 127.. _vbi-services:128 129.. flat-table:: Sliced VBI services130 :header-rows: 1131 :stub-columns: 0132 :widths: 2 1 1 2 2133 134 * - Symbol135 - Value136 - Reference137 - Lines, usually138 - Payload139 * - ``V4L2_SLICED_TELETEXT_B`` (Teletext System B)140 - 0x0001141 - :ref:`ets300706`,142 143 :ref:`itu653`144 - PAL/SECAM line 7-22, 320-335 (second field 7-22)145 - Last 42 of the 45 byte Teletext packet, that is without clock146 run-in and framing code, lsb first transmitted.147 * - ``V4L2_SLICED_VPS``148 - 0x0400149 - :ref:`ets300231`150 - PAL line 16151 - Byte number 3 to 15 according to Figure 9 of ETS 300 231, lsb152 first transmitted.153 * - ``V4L2_SLICED_CAPTION_525``154 - 0x1000155 - :ref:`cea608`156 - NTSC line 21, 284 (second field 21)157 - Two bytes in transmission order, including parity bit, lsb first158 transmitted.159 * - ``V4L2_SLICED_WSS_625``160 - 0x4000161 - :ref:`en300294`,162 163 :ref:`itu1119`164 - PAL/SECAM line 23165 - See :ref:`v4l2-sliced-vbi-cap-wss-625-payload` below.166 * - ``V4L2_SLICED_VBI_525``167 - 0x1000168 - :cspan:`2` Set of services applicable to 525 line systems.169 * - ``V4L2_SLICED_VBI_625``170 - 0x4401171 - :cspan:`2` Set of services applicable to 625 line systems.172 173 174.. raw:: latex175 176 \normalsize177 178.. _v4l2-sliced-vbi-cap-wss-625-payload:179 180V4L2_SLICED_VBI_CAP WSS_625 payload181~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~182 183The payload for ``V4L2_SLICED_WSS_625`` is:184 185 +-----+------------------+-----------------------+186 |Byte | 0 | 1 |187 +-----+--------+---------+-----------+-----------+188 | | msb | lsb | msb | lsb |189 | +-+-+-+--+--+-+-+--+--+-+--+---+---+--+-+--+190 | Bit |7|6|5|4 | 3|2|1|0 | x|x|13|12 | 11|10|9|8 |191 +-----+-+-+-+--+--+-+-+--+--+-+--+---+---+--+-+--+192 193 194Return Value195============196 197On success 0 is returned, on error -1 and the ``errno`` variable is set198appropriately. The generic error codes are described at the199:ref:`Generic Error Codes <gen-errors>` chapter.200 201EINVAL202 The value in the ``type`` field is wrong.203