Markus Heiser | 5377d91 | 2016-06-30 15:18:56 +0200 | [diff] [blame] | 1 | .. -*- coding: utf-8; mode: rst -*- |
| 2 | |
| 3 | .. _vidioc-g-sliced-vbi-cap: |
| 4 | |
| 5 | ***************************** |
| 6 | ioctl VIDIOC_G_SLICED_VBI_CAP |
| 7 | ***************************** |
| 8 | |
| 9 | *man VIDIOC_G_SLICED_VBI_CAP(2)* |
| 10 | |
| 11 | Query sliced VBI capabilities |
| 12 | |
| 13 | |
| 14 | Synopsis |
| 15 | ======== |
| 16 | |
| 17 | .. c:function:: int ioctl( int fd, int request, struct v4l2_sliced_vbi_cap *argp ) |
| 18 | |
| 19 | Arguments |
| 20 | ========= |
| 21 | |
| 22 | ``fd`` |
| 23 | File descriptor returned by :ref:`open() <func-open>`. |
| 24 | |
| 25 | ``request`` |
| 26 | VIDIOC_G_SLICED_VBI_CAP |
| 27 | |
| 28 | ``argp`` |
| 29 | |
| 30 | |
| 31 | Description |
| 32 | =========== |
| 33 | |
| 34 | To find out which data services are supported by a sliced VBI capture or |
| 35 | output device, applications initialize the ``type`` field of a struct |
| 36 | :ref:`v4l2_sliced_vbi_cap <v4l2-sliced-vbi-cap>`, clear the |
| 37 | ``reserved`` array and call the ``VIDIOC_G_SLICED_VBI_CAP`` ioctl. The |
| 38 | driver fills in the remaining fields or returns an EINVAL error code if |
| 39 | the sliced VBI API is unsupported or ``type`` is invalid. |
| 40 | |
| 41 | Note the ``type`` field was added, and the ioctl changed from read-only |
| 42 | to write-read, in Linux 2.6.19. |
| 43 | |
| 44 | |
| 45 | .. _v4l2-sliced-vbi-cap: |
| 46 | |
| 47 | .. flat-table:: struct v4l2_sliced_vbi_cap |
| 48 | :header-rows: 0 |
| 49 | :stub-columns: 0 |
| 50 | :widths: 3 3 2 2 2 |
| 51 | |
| 52 | |
| 53 | - .. row 1 |
| 54 | |
| 55 | - __u16 |
| 56 | |
| 57 | - ``service_set`` |
| 58 | |
| 59 | - :cspan:`2` A set of all data services supported by the driver. |
| 60 | Equal to the union of all elements of the ``service_lines`` array. |
| 61 | |
| 62 | - .. row 2 |
| 63 | |
| 64 | - __u16 |
| 65 | |
| 66 | - ``service_lines``\ [2][24] |
| 67 | |
| 68 | - :cspan:`2` Each element of this array contains a set of data |
| 69 | services the hardware can look for or insert into a particular |
| 70 | scan line. Data services are defined in :ref:`vbi-services`. |
| 71 | Array indices map to ITU-R line numbers (see also :ref:`vbi-525` |
| 72 | and :ref:`vbi-625`) as follows: |
| 73 | |
| 74 | - .. row 3 |
| 75 | |
| 76 | - |
| 77 | - |
| 78 | - Element |
| 79 | |
| 80 | - 525 line systems |
| 81 | |
| 82 | - 625 line systems |
| 83 | |
| 84 | - .. row 4 |
| 85 | |
| 86 | - |
| 87 | - |
| 88 | - ``service_lines``\ [0][1] |
| 89 | |
| 90 | - 1 |
| 91 | |
| 92 | - 1 |
| 93 | |
| 94 | - .. row 5 |
| 95 | |
| 96 | - |
| 97 | - |
| 98 | - ``service_lines``\ [0][23] |
| 99 | |
| 100 | - 23 |
| 101 | |
| 102 | - 23 |
| 103 | |
| 104 | - .. row 6 |
| 105 | |
| 106 | - |
| 107 | - |
| 108 | - ``service_lines``\ [1][1] |
| 109 | |
| 110 | - 264 |
| 111 | |
| 112 | - 314 |
| 113 | |
| 114 | - .. row 7 |
| 115 | |
| 116 | - |
| 117 | - |
| 118 | - ``service_lines``\ [1][23] |
| 119 | |
| 120 | - 286 |
| 121 | |
| 122 | - 336 |
| 123 | |
| 124 | - .. row 8 |
| 125 | |
| 126 | - |
| 127 | |
| 128 | - .. row 9 |
| 129 | |
| 130 | - |
| 131 | - |
| 132 | - :cspan:`2` The number of VBI lines the hardware can capture or |
| 133 | output per frame, or the number of services it can identify on a |
| 134 | given line may be limited. For example on PAL line 16 the hardware |
| 135 | may be able to look for a VPS or Teletext signal, but not both at |
| 136 | the same time. Applications can learn about these limits using the |
| 137 | :ref:`VIDIOC_S_FMT <vidioc-g-fmt>` ioctl as described in |
| 138 | :ref:`sliced`. |
| 139 | |
| 140 | - .. row 10 |
| 141 | |
| 142 | - |
| 143 | |
| 144 | - .. row 11 |
| 145 | |
| 146 | - |
| 147 | - |
| 148 | - :cspan:`2` Drivers must set ``service_lines`` [0][0] and |
| 149 | ``service_lines``\ [1][0] to zero. |
| 150 | |
| 151 | - .. row 12 |
| 152 | |
| 153 | - __u32 |
| 154 | |
| 155 | - ``type`` |
| 156 | |
| 157 | - Type of the data stream, see :ref:`v4l2-buf-type`. Should be |
| 158 | ``V4L2_BUF_TYPE_SLICED_VBI_CAPTURE`` or |
| 159 | ``V4L2_BUF_TYPE_SLICED_VBI_OUTPUT``. |
| 160 | |
| 161 | - .. row 13 |
| 162 | |
| 163 | - __u32 |
| 164 | |
| 165 | - ``reserved``\ [3] |
| 166 | |
| 167 | - :cspan:`2` This array is reserved for future extensions. |
| 168 | Applications and drivers must set it to zero. |
| 169 | |
| 170 | |
| 171 | |
| 172 | .. _vbi-services: |
| 173 | |
| 174 | .. flat-table:: Sliced VBI services |
| 175 | :header-rows: 1 |
| 176 | :stub-columns: 0 |
| 177 | :widths: 2 1 1 2 2 |
| 178 | |
| 179 | |
| 180 | - .. row 1 |
| 181 | |
| 182 | - Symbol |
| 183 | |
| 184 | - Value |
| 185 | |
| 186 | - Reference |
| 187 | |
| 188 | - Lines, usually |
| 189 | |
| 190 | - Payload |
| 191 | |
| 192 | - .. row 2 |
| 193 | |
| 194 | - ``V4L2_SLICED_TELETEXT_B`` (Teletext System B) |
| 195 | |
| 196 | - 0x0001 |
| 197 | |
| 198 | - :ref:`ets300706`, :ref:`itu653` |
| 199 | |
| 200 | - PAL/SECAM line 7-22, 320-335 (second field 7-22) |
| 201 | |
| 202 | - Last 42 of the 45 byte Teletext packet, that is without clock |
| 203 | run-in and framing code, lsb first transmitted. |
| 204 | |
| 205 | - .. row 3 |
| 206 | |
| 207 | - ``V4L2_SLICED_VPS`` |
| 208 | |
| 209 | - 0x0400 |
| 210 | |
| 211 | - :ref:`ets300231` |
| 212 | |
| 213 | - PAL line 16 |
| 214 | |
| 215 | - Byte number 3 to 15 according to Figure 9 of ETS 300 231, lsb |
| 216 | first transmitted. |
| 217 | |
| 218 | - .. row 4 |
| 219 | |
| 220 | - ``V4L2_SLICED_CAPTION_525`` |
| 221 | |
| 222 | - 0x1000 |
| 223 | |
| 224 | - :ref:`cea608` |
| 225 | |
| 226 | - NTSC line 21, 284 (second field 21) |
| 227 | |
| 228 | - Two bytes in transmission order, including parity bit, lsb first |
| 229 | transmitted. |
| 230 | |
| 231 | - .. row 5 |
| 232 | |
| 233 | - ``V4L2_SLICED_WSS_625`` |
| 234 | |
| 235 | - 0x4000 |
| 236 | |
| 237 | - :ref:`en300294`, :ref:`itu1119` |
| 238 | |
| 239 | - PAL/SECAM line 23 |
| 240 | |
| 241 | - |
| 242 | |
| 243 | :: |
| 244 | |
| 245 | Byte 0 1 |
| 246 | msb lsb msb lsb |
| 247 | Bit 7 6 5 4 3 2 1 0 x x 13 12 11 10 9 |
| 248 | |
| 249 | - .. row 6 |
| 250 | |
| 251 | - ``V4L2_SLICED_VBI_525`` |
| 252 | |
| 253 | - 0x1000 |
| 254 | |
| 255 | - :cspan:`2` Set of services applicable to 525 line systems. |
| 256 | |
| 257 | - .. row 7 |
| 258 | |
| 259 | - ``V4L2_SLICED_VBI_625`` |
| 260 | |
| 261 | - 0x4401 |
| 262 | |
| 263 | - :cspan:`2` Set of services applicable to 625 line systems. |
| 264 | |
| 265 | |
| 266 | |
| 267 | Return Value |
| 268 | ============ |
| 269 | |
| 270 | On success 0 is returned, on error -1 and the ``errno`` variable is set |
| 271 | appropriately. The generic error codes are described at the |
| 272 | :ref:`Generic Error Codes <gen-errors>` chapter. |
| 273 | |
| 274 | EINVAL |
| 275 | The value in the ``type`` field is wrong. |
| 276 | |
| 277 | |
| 278 | .. ------------------------------------------------------------------------------ |
| 279 | .. This file was automatically converted from DocBook-XML with the dbxml |
| 280 | .. library (https://github.com/return42/sphkerneldoc). The origin XML comes |
| 281 | .. from the linux kernel, refer to: |
| 282 | .. |
| 283 | .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook |
| 284 | .. ------------------------------------------------------------------------------ |