€•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]”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$]”h&]”Œ xml:space”Œpreserve”uh1h¡hhhžhhŸŒT/var/lib/git/docbuild/linux/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst”h KubhŒtarget”“”)”}”(hŒ.. _sliced:”h]”h}”(h]”h ]”h"]”h$]”h&]”Œrefid”Œsliced”uh1h´h KhhhžhhŸh³ubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒSliced VBI Data Interface”h]”hŒSliced VBI Data Interface”…””}”(hhÉhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÇhhÄhžhhŸh³h KubhŒ paragraph”“”)”}”(hŒüVBI stands for Vertical Blanking Interval, a gap in the sequence of lines of an analog video signal. During VBI no picture information is transmitted, allowing some time while the electron beam of a cathode ray tube TV returns to the top of the screen.”h]”hŒüVBI stands for Vertical Blanking Interval, a gap in the sequence of lines of an analog video signal. During VBI no picture information is transmitted, allowing some time while the electron beam of a cathode ray tube TV returns to the top of the screen.”…””}”(hhÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h×hŸh³h K hhÄhžhubhØ)”}”(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 ”…””}”(hhçhžhhŸNh NubhŒemphasis”“”)”}”(hŒ*not*”h]”hŒnot”…””}”(hhñhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hïhhçubhŒ# do this by software, see also the ”…””}”(hhçhžhhŸNh Nubh)”}”(hŒ":ref:`raw VBI interface `”h]”hŒinline”“”)”}”(hjh]”hŒraw VBI interface”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”Œ&userspace-api/media/v4l/dev-sliced-vbi”Œ refdomain”jŒreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆŒ reftarget”Œraw-vbi”uh1hhŸh³h KhhçubhŒ„. The data is passed as short packets of fixed size, covering one scan line each. The number of packets per video frame is variable.”…””}”(hhçhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h×hŸh³h KhhÄhžhubhØ)”}”(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 ”…””}”(hj2hžhhŸNh NubhŒliteral”“”)”}”(hŒ``/dev/vbi``”h]”hŒ/dev/vbi”…””}”(hj<hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j:hj2ubhŒ device is ”…””}”(hj2hžhhŸNh Nubhð)”}”(hŒ*raw*”h]”hŒraw”…””}”(hjNhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hïhj2ubhŒZ VBI capturing or output, and the sliced VBI function is only available after calling the ”…””}”(hj2hžhhŸNh Nubh)”}”(hŒ":ref:`VIDIOC_S_FMT `”h]”j)”}”(hjbh]”hŒVIDIOC_S_FMT”…””}”(hjdhžhhŸNh Nubah}”(h]”h ]”(jŒstd”Œstd-ref”eh"]”h$]”h&]”uh1jhj`ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”jnŒreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆj&Œvidioc_g_fmt”uh1hhŸh³h Khj2ubhŒ$ ioctl as defined below. Likewise a ”…””}”(hj2hžhhŸNh Nubj;)”}”(hŒ``/dev/video``”h]”hŒ /dev/video”…””}”(hj„hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j:hj2ubhŒã device may support the sliced VBI API, however the default function here is video capturing or output. Different file descriptors must be used to pass raw and sliced VBI data simultaneously, if this is supported by the driver.”…””}”(hj2hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h×hŸh³h KhhÄhžhubhÃ)”}”(hhh]”(hÈ)”}”(hŒQuerying Capabilities”h]”hŒQuerying Capabilities”…””}”(hjŸhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÇhjœhžhhŸh³h K ubhØ)”}”(hXDevices supporting the sliced VBI capturing or output API set the ``V4L2_CAP_SLICED_VBI_CAPTURE`` or ``V4L2_CAP_SLICED_VBI_OUTPUT`` flag respectively, in the ``capabilities`` field of struct :c:type:`v4l2_capability` returned by the :ref:`VIDIOC_QUERYCAP` ioctl. At least one of the read/write or streaming :ref:`I/O methods ` must be supported. Sliced VBI devices may have a tuner or modulator.”h]”(hŒBDevices supporting the sliced VBI capturing or output API set the ”…””}”(hjhžhhŸNh Nubj;)”}”(hŒ``V4L2_CAP_SLICED_VBI_CAPTURE``”h]”hŒV4L2_CAP_SLICED_VBI_CAPTURE”…””}”(hjµhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j:hjubhŒ or ”…””}”(hjhžhhŸNh Nubj;)”}”(hŒ``V4L2_CAP_SLICED_VBI_OUTPUT``”h]”hŒV4L2_CAP_SLICED_VBI_OUTPUT”…””}”(hjÇhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j:hjubhŒ flag respectively, in the ”…””}”(hjhžhhŸNh Nubj;)”}”(hŒ``capabilities``”h]”hŒcapabilities”…””}”(hjÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j:hjubhŒ field of struct ”…””}”(hjhžhhŸNh Nubh)”}”(hŒ:c:type:`v4l2_capability`”h]”j;)”}”(hjíh]”hŒv4l2_capability”…””}”(hjïhžhhŸNh Nubah}”(h]”h ]”(jŒc”Œc-type”eh"]”h$]”h&]”uh1j:hjëubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”jùŒreftype”Œtype”Œrefexplicit”‰Œrefwarn”‰Œc:parent_key”Œsphinx.domains.c”Œ LookupKey”“”)”}”Œdata”]”jŒ ASTIdentifier”“”)”}”Œ identifier”ŒV4L”sbN†”asbj&Œv4l2_capability”uh1hhŸh³h K"hjubhŒ returned by the ”…””}”(hjhžhhŸNh Nubh)”}”(hŒ:ref:`VIDIOC_QUERYCAP`”h]”j)”}”(hj h]”hŒVIDIOC_QUERYCAP”…””}”(hj"hžhhŸNh Nubah}”(h]”h ]”(jŒstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”j,Œreftype”Œref”Œrefexplicit”‰Œrefwarn”ˆj&Œvidioc_querycap”uh1hhŸh³h K"hjubhŒ4 ioctl. At least one of the read/write or streaming ”…””}”(hjhžhhŸNh Nubh)”}”(hŒ:ref:`I/O methods `”h]”j)”}”(hjDh]”hŒI/O methods”…””}”(hjFhžhhŸNh Nubah}”(h]”h ]”(jŒstd”Œstd-ref”eh"]”h$]”h&]”uh1jhjBubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”jPŒreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆj&Œio”uh1hhŸh³h K"hjubhŒE must be supported. Sliced VBI devices may have a tuner or modulator.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h×hŸh³h K"hjœhžhubeh}”(h]”Œquerying-capabilities”ah ]”h"]”Œquerying capabilities”ah$]”h&]”uh1hÂhhÄhžhhŸh³h K ubhÃ)”}”(hhh]”(hÈ)”}”(hŒSupplemental Functions”h]”hŒSupplemental Functions”…””}”(hjwhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÇhjthžhhŸh³h K+ubhØ)”}”(hXBSliced VBI devices shall support :ref:`video input or output