€•>ùŒsphinx.addnodes”Œdocument”“”)�”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)�”}”(hhh]”(hŒ pending_xref”“”)�”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…”�”}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ7/translations/zh_CN/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)�”}”(hhh]”hŒChinese (Traditional)”…”�”}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/zh_TW/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)�”}”(hhh]”hŒItalian”…”�”}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/it_IT/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)�”}”(hhh]”hŒJapanese”…”�”}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/ja_JP/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)�”}”(hhh]”hŒKorean”…”�”}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/ko_KR/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)�”}”(hhh]”hŒPortuguese (Brazilian)”…”�”}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/pt_BR/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)�”}”(hhh]”hŒSpanish”…”�”}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ7/translations/sp_SP/userspace-api/media/v4l/dev-raw-vbi”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(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”uh1hµhhh²hh³ŒQ/var/lib/git/docbuild/linux/Documentation/userspace-api/media/v4l/dev-raw-vbi.rst”h´KubhŒtarget”“”)�”}”(hŒ .. _raw-vbi:”h]”h}”(h]”h ]”h"]”h$]”h&]”Œrefid”Œraw-vbi”uh1hÈh´Khhh²hh³hÇubhŒsection”“”)�”}”(hhh]”(hŒtitle”“”)�”}”(hŒRaw VBI Data Interface”h]”hŒRaw VBI Data Interface”…”�”}”(hhÝh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhhØh²hh³hÇh´KubhŒ paragraph”“”)�”}”(hXàVBI is an abbreviation of 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. Using an oscilloscope you will find here the vertical synchronization pulses and short data packages ASK modulated [#f1]_ onto the video signal. These are transmissions of services such as Teletext or Closed Caption.”h]”(hX{VBI is an abbreviation of 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. Using an oscilloscope you will find here the vertical synchronization pulses and short data packages ASK modulated ”…”�”}”(hhíh²hh³Nh´NubhŒfootnote_reference”“”)�”}”(hŒ[#f1]_”h]”hŒ1”…”�”}”(hh÷h²hh³Nh´Nubah}”(h]”Œid1”ah ]”h"]”h$]”h&]”Œauto”KhÔŒf1”Œdocname”Œ#userspace-api/media/v4l/dev-raw-vbi”uh1hõhhíŒresolved”KubhŒ_ onto the video signal. These are transmissions of services such as Teletext or Closed Caption.”…”�”}”(hhíh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´K hhØh²hubhì)�”}”(hŒþSubject of this interface type is raw VBI data, as sampled off a video signal, or to be added to a signal for output. The data format is similar to uncompressed video images, a number of lines times a number of samples per line, we call this a VBI image.”h]”hŒþSubject of this interface type is raw VBI data, as sampled off a video signal, or to be added to a signal for output. The data format is similar to uncompressed video images, a number of lines times a number of samples per line, we call this a VBI image.”…”�”}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´KhhØh²hubhì)�”}”(hX>Conventionally V4L2 VBI devices are accessed through character device special files named ``/dev/vbi`` and ``/dev/vbi0`` to ``/dev/vbi31`` with major number 81 and minor numbers 224 to 255. ``/dev/vbi`` is typically a symbolic link to the preferred VBI device. This convention applies to both input and output devices.”h]”(hŒZConventionally V4L2 VBI devices are accessed through character device special files named ”…”�”}”(hj#h²hh³Nh´NubhŒliteral”“”)�”}”(hŒ ``/dev/vbi``”h]”hŒ/dev/vbi”…”�”}”(hj-h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj#ubhŒ and ”…”�”}”(hj#h²hh³Nh´Nubj,)�”}”(hŒ ``/dev/vbi0``”h]”hŒ /dev/vbi0”…”�”}”(hj?h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj#ubhŒ to ”…”�”}”(hj#h²hh³Nh´Nubj,)�”}”(hŒ``/dev/vbi31``”h]”hŒ /dev/vbi31”…”�”}”(hjQh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj#ubhŒ4 with major number 81 and minor numbers 224 to 255. ”…”�”}”(hj#h²hh³Nh´Nubj,)�”}”(hŒ ``/dev/vbi``”h]”hŒ/dev/vbi”…”�”}”(hjch²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj#ubhŒt is typically a symbolic link to the preferred VBI device. This convention applies to both input and output devices.”…”�”}”(hj#h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´KhhØh²hubhì)�”}”(hXdTo address the problems of finding related video and VBI devices VBI capturing and output is also available as device function under ``/dev/video``. To capture or output raw VBI data with these devices applications must call the :ref:`VIDIOC_S_FMT ` ioctl. Accessed as ``/dev/vbi``, raw VBI capturing or output is the default device function.”h]”(hŒ…To address the problems of finding related video and VBI devices VBI capturing and output is also available as device function under ”…”�”}”(hj{h²hh³Nh´Nubj,)�”}”(hŒ``/dev/video``”h]”hŒ /dev/video”…”�”}”(hjƒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj{ubhŒR. To capture or output raw VBI data with these devices applications must call the ”…”�”}”(hj{h²hh³Nh´Nubh)�”}”(hŒ":ref:`VIDIOC_S_FMT `”h]”hŒinline”“”)�”}”(hj—h]”hŒ VIDIOC_S_FMT”…”�”}”(hj›h²hh³Nh´Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-ref”eh"]”h$]”h&]”uh1j™hj•ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”j¦Œreftype”Œref”Œ refexplicit”ˆŒrefwarn”ˆŒ reftarget”Œ vidioc_g_fmt”uh1hh³hÇh´Khj{ubhŒ ioctl. Accessed as ”…”�”}”(hj{h²hh³Nh´Nubj,)�”}”(hŒ ``/dev/vbi``”h]”hŒ/dev/vbi”…”�”}”(hj½h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hj{ubhŒ=, raw VBI capturing or output is the default device function.”…”�”}”(hj{h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´KhhØh²hubh×)�”}”(hhh]”(hÜ)�”}”(hŒQuerying Capabilities”h]”hŒQuerying Capabilities”…”�”}”(hjØh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhjÕh²hh³hÇh´K%ubhì)�”}”(hXxDevices supporting the raw VBI capturing or output API set the ``V4L2_CAP_VBI_CAPTURE`` or ``V4L2_CAP_VBI_OUTPUT`` flags, 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 I/O methods must be supported. VBI devices may or may not have a tuner or modulator.”h]”(hŒ?Devices supporting the raw VBI capturing or output API set the ”…”�”}”(hjæh²hh³Nh´Nubj,)�”}”(hŒ``V4L2_CAP_VBI_CAPTURE``”h]”hŒV4L2_CAP_VBI_CAPTURE”…”�”}”(hjîh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hjæubhŒ or ”…”�”}”(hjæh²hh³Nh´Nubj,)�”}”(hŒ``V4L2_CAP_VBI_OUTPUT``”h]”hŒV4L2_CAP_VBI_OUTPUT”…”�”}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hjæubhŒ flags, respectively, in the ”…”�”}”(hjæh²hh³Nh´Nubj,)�”}”(hŒ``capabilities``”h]”hŒ capabilities”…”�”}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j+hjæubhŒ field of struct ”…”�”}”(hjæh²hh³Nh´Nubh)�”}”(hŒ:c:type:`v4l2_capability`”h]”j,)�”}”(hj&h]”hŒv4l2_capability”…”�”}”(hj(h²hh³Nh´Nubah}”(h]”h ]”(j¥Œc”Œc-type”eh"]”h$]”h&]”uh1j+hj$ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”j2Œreftype”Œtype”Œ refexplicit”‰Œrefwarn”‰Œ c:parent_key”Œsphinx.domains.c”Œ LookupKey”“”)�”}”Œdata”]”jDŒ ASTIdentifier”“”)�”}”Œ identifier”ŒV4L”sbN†”asbj·Œv4l2_capability”uh1hh³hÇh´K'hjæubhŒ returned by the ”…”�”}”(hjæh²hh³Nh´Nubh)�”}”(hŒ:ref:`VIDIOC_QUERYCAP`”h]”jš)�”}”(hjYh]”hŒVIDIOC_QUERYCAP”…”�”}”(hj[h²hh³Nh´Nubah}”(h]”h ]”(j¥Œstd”Œstd-ref”eh"]”h$]”h&]”uh1j™hjWubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j Œ refdomain”jeŒreftype”Œref”Œ refexplicit”‰Œrefwarn”ˆj·Œvidioc_querycap”uh1hh³hÇh´K'hjæubhŒˆ ioctl. At least one of the read/write or streaming I/O methods must be supported. VBI devices may or may not have a tuner or modulator.”…”�”}”(hjæh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hëh³hÇh´K'hjÕh²hubeh}”(h]”Œquerying-capabilities”ah ]”h"]”Œquerying capabilities”ah$]”h&]”uh1hÖhhØh²hh³hÇh´K%ubh×)�”}”(hhh]”(hÜ)�”}”(hŒSupplemental Functions”h]”hŒSupplemental Functions”…”�”}”(hjŒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÛhj‰h²hh³hÇh´K0ubhì)�”}”(hXVBI devices shall support :ref:`video input or output