From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- .../DocBook/v4l/vidioc-g-sliced-vbi-cap.xml | 264 +++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml (limited to 'Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml') diff --git a/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml b/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml new file mode 100644 index 00000000..10e721b1 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-g-sliced-vbi-cap.xml @@ -0,0 +1,264 @@ + + + ioctl VIDIOC_G_SLICED_VBI_CAP + &manvol; + + + + VIDIOC_G_SLICED_VBI_CAP + Query sliced VBI capabilities + + + + + + int ioctl + int fd + int request + struct v4l2_sliced_vbi_cap *argp + + + + + + Arguments + + + + fd + + &fd; + + + + 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 &v4l2-sliced-vbi-cap;, +clear the reserved array and +call the VIDIOC_G_SLICED_VBI_CAP ioctl. The +driver fills in the remaining fields or returns an &EINVAL; 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. + + + struct <structname>v4l2_sliced_vbi_cap</structname> + + + + + + + + + + __u16 + service_set + A set of all data services +supported by the driver. Equal to the union of all elements of the +service_lines array. + + + __u16 + service_lines[2][24] + 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 . Array indices map to ITU-R +line numbers (see also and ) 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 + + + + + + + + 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 &VIDIOC-S-FMT; ioctl as described in . + + + + + + + + Drivers must set +service_lines[0][0] and +service_lines[1][0] to zero. + + + &v4l2-buf-type; + type + Type of the data stream, see . Should be +V4L2_BUF_TYPE_SLICED_VBI_CAPTURE or +V4L2_BUF_TYPE_SLICED_VBI_OUTPUT. + + + __u32 + reserved[3] + This array is reserved for future +extensions. Applications and drivers must set it to zero. + + + +
+ + + + Sliced VBI services + + + + + + + + + + Symbol + Value + Reference + Lines, usually + Payload + + + + + V4L2_SLICED_TELETEXT_B (Teletext +System B) + 0x0001 + , + 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 + + PAL line 16 + Byte number 3 to 15 according to Figure 9 of +ETS 300 231, lsb first transmitted. + + + V4L2_SLICED_CAPTION_525 + 0x1000 + + NTSC line 21, 284 (second field 21) + Two bytes in transmission order, including parity +bit, lsb first transmitted. + + + V4L2_SLICED_WSS_625 + 0x4000 + , + 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 + + + + V4L2_SLICED_VBI_525 + 0x1000 + Set of services applicable to 525 +line systems. + + + V4L2_SLICED_VBI_625 + 0x4401 + Set of services applicable to 625 +line systems. + + + +
+ + + + + &return-value; + + + + EINVAL + + The device does not support sliced VBI capturing or +output, or the value in the type field is +wrong. + + + + + + + -- cgit v1.2.3