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diff --git a/Documentation/media/uapi/v4l/vidioc-g-sliced-vbi-cap.rst b/Documentation/media/uapi/v4l/vidioc-g-sliced-vbi-cap.rst new file mode 100644 index 000000000..f1f661d02 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-g-sliced-vbi-cap.rst @@ -0,0 +1,276 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_G_SLICED_VBI_CAP: + +***************************** +ioctl VIDIOC_G_SLICED_VBI_CAP +***************************** + +Name +==== + +VIDIOC_G_SLICED_VBI_CAP - Query sliced VBI capabilities + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, struct v4l2_sliced_vbi_cap *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_G_SLICED_VBI_CAP + +``argp`` + + +Description +=========== + +To find out which data services are supported by a sliced VBI capture or +output device, applications initialize the ``type`` field of a struct +:ref:`v4l2_sliced_vbi_cap <v4l2-sliced-vbi-cap>`, clear the +``reserved`` array and call the :ref:`VIDIOC_G_SLICED_VBI_CAP <VIDIOC_G_SLICED_VBI_CAP>` ioctl. The +driver fills in the remaining fields or returns an ``EINVAL`` error code if +the sliced VBI API is unsupported or ``type`` is invalid. + +.. note:: The ``type`` field was added, and the ioctl changed from read-only + to write-read, in Linux 2.6.19. + + +.. _v4l2-sliced-vbi-cap: + +.. flat-table:: struct v4l2_sliced_vbi_cap + :header-rows: 0 + :stub-columns: 0 + :widths: 3 3 2 2 2 + + + - .. row 1 + + - __u16 + + - ``service_set`` + + - :cspan:`2` A set of all data services supported by the driver. + Equal to the union of all elements of the ``service_lines`` array. + + - .. row 2 + + - __u16 + + - ``service_lines``\ [2][24] + + - :cspan:`2` Each element of this array contains a set of data + services the hardware can look for or insert into a particular + scan line. Data services are defined in :ref:`vbi-services`. + Array indices map to ITU-R line numbers (see also :ref:`vbi-525` + and :ref:`vbi-625`) as follows: + + - .. row 3 + + - + - + - Element + + - 525 line systems + + - 625 line systems + + - .. row 4 + + - + - + - ``service_lines``\ [0][1] + + - 1 + + - 1 + + - .. row 5 + + - + - + - ``service_lines``\ [0][23] + + - 23 + + - 23 + + - .. row 6 + + - + - + - ``service_lines``\ [1][1] + + - 264 + + - 314 + + - .. row 7 + + - + - + - ``service_lines``\ [1][23] + + - 286 + + - 336 + + - .. row 8 + + - + + - .. row 9 + + - + - + - :cspan:`2` 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 may be 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. Applications can learn about these limits using the + :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl as described in + :ref:`sliced`. + + - .. row 10 + + - + + - .. row 11 + + - + - + - :cspan:`2` Drivers must set ``service_lines`` [0][0] and + ``service_lines``\ [1][0] to zero. + + - .. row 12 + + - __u32 + + - ``type`` + + - Type of the data stream, see :ref:`v4l2-buf-type`. Should be + ``V4L2_BUF_TYPE_SLICED_VBI_CAPTURE`` or + ``V4L2_BUF_TYPE_SLICED_VBI_OUTPUT``. + + - .. row 13 + + - __u32 + + - ``reserved``\ [3] + + - :cspan:`2` This array is reserved for future extensions. + Applications and drivers must set it to zero. + + + +.. _vbi-services: + +.. flat-table:: Sliced VBI services + :header-rows: 1 + :stub-columns: 0 + :widths: 2 1 1 2 2 + + + - .. row 1 + + - Symbol + + - Value + + - Reference + + - Lines, usually + + - Payload + + - .. row 2 + + - ``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. + + - .. row 3 + + - ``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. + + - .. row 4 + + - ``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. + + - .. row 5 + + - ``V4L2_SLICED_WSS_625`` + + - 0x4000 + + - :ref:`en300294`, :ref:`itu1119` + + - PAL/SECAM line 23 + + - + + :: + + Byte 0 1 + msb lsb msb lsb + Bit 7 6 5 4 3 2 1 0 x x 13 12 11 10 9 + + - .. row 6 + + - ``V4L2_SLICED_VBI_525`` + + - 0x1000 + + - :cspan:`2` Set of services applicable to 525 line systems. + + - .. row 7 + + - ``V4L2_SLICED_VBI_625`` + + - 0x4401 + + - :cspan:`2` Set of services applicable to 625 line systems. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + The value in the ``type`` field is wrong. |