€•Œsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œtranslations”Œ LanguagesNode”“”)”}”(hhh]”(hŒpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ:/translations/zh_CN/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/zh_TW/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/it_IT/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/ja_JP/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/ko_KR/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/pt_BR/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ:/translations/sp_SP/userspace-api/media/v4l/dev-sliced-vbi”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ8SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later”h]”hŒ8SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later”…””}”hh·sbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1hµhhh²hh³ŒT/var/lib/git/docbuild/linux/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst”h´KubhŒtarget”“”)”}”(hŒ.. _sliced:”h]”h}”(h]”h ]”h"]”h$]”h&]”Œrefid”Œsliced”uh1hÈh´Khhh²hh³hÇubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒSliced VBI Data Interface”h]”hŒSliced VBI Data Interface”…””}”(hhÝh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhhØh²hh³hÇh´KubhŒ paragraph”“”)”}”(hŒüVBI 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.”h]”hŒüVBI 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.”…””}”(hhíh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´K hhØh²hubhì)”}”(hX,Sliced VBI devices use hardware to demodulate data transmitted in the VBI. V4L2 drivers shall *not* do this by software, see also the :ref:`raw VBI interface `. The data is passed as short packets of fixed size, covering one scan line each. The number of packets per video frame is variable.”h]”(hŒ^Sliced VBI devices use hardware to demodulate data transmitted in the VBI. V4L2 drivers shall ”…””}”(hhûh²hh³Nh´NubhŒemphasis”“”)”}”(hŒ*not*”h]”hŒnot”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhhûubhŒ# do this by software, see also the ”…””}”(hhûh²hh³Nh´Nubh)”}”(hŒ":ref:`raw VBI interface `”h]”hŒinline”“”)”}”(hjh]”hŒraw VBI interface”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”Œ&userspace-api/media/v4l/dev-sliced-vbi”Œ refdomain”j(Œreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆŒ reftarget”Œraw-vbi”uh1hh³hÇh´KhhûubhŒ„. The data is passed as short packets of fixed size, covering one scan line each. The number of packets per video frame is variable.”…””}”(hhûh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´KhhØh²hubhì)”}”(hX_Sliced VBI capture and output devices are accessed through the same character special files as raw VBI devices. When a driver supports both interfaces, the default function of a ``/dev/vbi`` device is *raw* VBI capturing or output, and the sliced VBI function is only available after calling the :ref:`VIDIOC_S_FMT ` ioctl as defined below. Likewise a ``/dev/video`` device may support the sliced VBI API, however the default function here is video capturing or output. Different file descriptors must be used to pass raw and sliced VBI data simultaneously, if this is supported by the driver.”h]”(hŒ²Sliced VBI capture and output devices are accessed through the same character special files as raw VBI devices. When a driver supports both interfaces, the default function of a ”…””}”(hjFh²hh³Nh´NubhŒliteral”“”)”}”(hŒ``/dev/vbi``”h]”hŒ/dev/vbi”…””}”(hjPh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jNhjFubhŒ device is ”…””}”(hjFh²hh³Nh´Nubj)”}”(hŒ*raw*”h]”hŒraw”…””}”(hjbh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjFubhŒZ VBI capturing or output, and the sliced VBI function is only available after calling the ”…””}”(hjFh²hh³Nh´Nubh)”}”(hŒ":ref:`VIDIOC_S_FMT `”h]”j)”}”(hjvh]”hŒVIDIOC_S_FMT”…””}”(hjxh²hh³Nh´Nubah}”(h]”h ]”(j'Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjtubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j4Œ refdomain”j‚Œreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆj:Œvidioc_g_fmt”uh1hh³hÇh´KhjFubhŒ$ ioctl as defined below. Likewise a ”…””}”(hjFh²hh³Nh´NubjO)”}”(hŒ``/dev/video``”h]”hŒ /dev/video”…””}”(hj˜h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jNhjFubhŒã device may support the sliced VBI API, however the default function here is video capturing or output. Different file descriptors must be used to pass raw and sliced VBI data simultaneously, if this is supported by the driver.”…””}”(hjFh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´KhhØh²hubh×)”}”(hhh]”(hÜ)”}”(hŒQuerying Capabilities”h]”hŒQuerying Capabilities”…””}”(hj³h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhj°h²hh³hÇh´K ubhì)”}”(hXDevices supporting the sliced VBI capturing or output API set the ``V4L2_CAP_SLICED_VBI_CAPTURE`` or ``V4L2_CAP_SLICED_VBI_OUTPUT`` flag respectively, in the ``capabilities`` field of struct :c:type:`v4l2_capability` returned by the :ref:`VIDIOC_QUERYCAP` ioctl. At least one of the read/write or streaming :ref:`I/O methods ` must be supported. Sliced VBI devices may have a tuner or modulator.”h]”(hŒBDevices supporting the sliced VBI capturing or output API set the ”…””}”(hjÁh²hh³Nh´NubjO)”}”(hŒ``V4L2_CAP_SLICED_VBI_CAPTURE``”h]”hŒV4L2_CAP_SLICED_VBI_CAPTURE”…””}”(hjÉh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jNhjÁubhŒ or ”…””}”(hjÁh²hh³Nh´NubjO)”}”(hŒ``V4L2_CAP_SLICED_VBI_OUTPUT``”h]”hŒV4L2_CAP_SLICED_VBI_OUTPUT”…””}”(hjÛh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jNhjÁubhŒ flag respectively, in the ”…””}”(hjÁh²hh³Nh´NubjO)”}”(hŒ``capabilities``”h]”hŒcapabilities”…””}”(hjíh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jNhjÁubhŒ field of struct ”…””}”(hjÁh²hh³Nh´Nubh)”}”(hŒ:c:type:`v4l2_capability`”h]”jO)”}”(hjh]”hŒv4l2_capability”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”(j'Œc”Œc-type”eh"]”h$]”h&]”uh1jNhjÿubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j4Œ refdomain”j Œreftype”Œtype”Œrefexplicit”‰Œrefwarn”‰Œc:parent_key”Œsphinx.domains.c”Œ LookupKey”“”)”}”Œdata”]”jŒ ASTIdentifier”“”)”}”Œ identifier”ŒV4L”sbN†”asbj:Œv4l2_capability”uh1hh³hÇh´K"hjÁubhŒ returned by the ”…””}”(hjÁh²hh³Nh´Nubh)”}”(hŒ:ref:`VIDIOC_QUERYCAP`”h]”j)”}”(hj4h]”hŒVIDIOC_QUERYCAP”…””}”(hj6h²hh³Nh´Nubah}”(h]”h ]”(j'Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jhj2ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j4Œ refdomain”j@Œreftype”Œref”Œrefexplicit”‰Œrefwarn”ˆj:Œvidioc_querycap”uh1hh³hÇh´K"hjÁubhŒ4 ioctl. At least one of the read/write or streaming ”…””}”(hjÁh²hh³Nh´Nubh)”}”(hŒ:ref:`I/O methods `”h]”j)”}”(hjXh]”hŒI/O methods”…””}”(hjZh²hh³Nh´Nubah}”(h]”h ]”(j'Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjVubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j4Œ refdomain”jdŒreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆj:Œio”uh1hh³hÇh´K"hjÁubhŒE must be supported. Sliced VBI devices may have a tuner or modulator.”…””}”(hjÁh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´K"hj°h²hubeh}”(h]”Œquerying-capabilities”ah ]”h"]”Œquerying capabilities”ah$]”h&]”uh1hÖhhØh²hh³hÇh´K ubh×)”}”(hhh]”(hÜ)”}”(hŒSupplemental Functions”h]”hŒSupplemental Functions”…””}”(hj‹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhjˆh²hh³hÇh´K+ubhì)”}”(hXBSliced VBI devices shall support :ref:`video input or output