^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) .. c:namespace:: V4L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) .. _VIDIOC_ENUM_FREQ_BANDS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) ****************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) ioctl VIDIOC_ENUM_FREQ_BANDS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) ****************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) ====
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) VIDIOC_ENUM_FREQ_BANDS - Enumerate supported frequency bands
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Synopsis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) .. c:macro:: VIDIOC_ENUM_FREQ_BANDS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) ``int ioctl(int fd, VIDIOC_ENUM_FREQ_BANDS, struct v4l2_frequency_band *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) Arguments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) =========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) ``fd``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) File descriptor returned by :c:func:`open()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) ``argp``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) Pointer to struct :c:type:`v4l2_frequency_band`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Enumerates the frequency bands that a tuner or modulator supports. To do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) this applications initialize the ``tuner``, ``type`` and ``index``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) fields, and zero out the ``reserved`` array of a struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) :c:type:`v4l2_frequency_band` and call the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) :ref:`VIDIOC_ENUM_FREQ_BANDS` ioctl with a pointer to this structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) This ioctl is supported if the ``V4L2_TUNER_CAP_FREQ_BANDS`` capability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) of the corresponding tuner/modulator is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) .. tabularcolumns:: |p{2.9cm}|p{2.9cm}|p{5.8cm}|p{2.9cm}|p{3.0cm}|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) .. c:type:: v4l2_frequency_band
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) .. flat-table:: struct v4l2_frequency_band
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) :header-rows: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) :stub-columns: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) :widths: 1 1 2 1 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) - ``tuner``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) - The tuner or modulator index number. This is the same value as in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) the struct :c:type:`v4l2_input` ``tuner`` field and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) the struct :c:type:`v4l2_tuner` ``index`` field, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) the struct :c:type:`v4l2_output` ``modulator`` field
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) and the struct :c:type:`v4l2_modulator` ``index``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) - ``type``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) - The tuner type. This is the same value as in the struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) :c:type:`v4l2_tuner` ``type`` field. The type must be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) ``V4L2_TUNER_RADIO`` for modulators (currently only radio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) modulators are supported). See :c:type:`v4l2_tuner_type`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) - ``index``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) - Identifies the frequency band, set by the application.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) - ``capability``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) - :cspan:`2` The tuner/modulator capability flags for this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) frequency band, see :ref:`tuner-capability`. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) ``V4L2_TUNER_CAP_LOW`` or ``V4L2_TUNER_CAP_1HZ`` capability must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) be the same for all frequency bands of the selected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) tuner/modulator. So either all bands have that capability set, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) none of them have that capability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) - ``rangelow``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) - :cspan:`2` The lowest tunable frequency in units of 62.5 kHz, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) of 62.5 Hz, for this frequency band. A 1 Hz unit is used when the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) - ``rangehigh``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) - :cspan:`2` The highest tunable frequency in units of 62.5 kHz,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) or if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) units of 62.5 Hz, for this frequency band. A 1 Hz unit is used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) - ``modulation``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) - :cspan:`2` The supported modulation systems of this frequency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) band. See :ref:`band-modulation`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) .. note::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) Currently only one modulation system per frequency band
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) is supported. More work will need to be done if multiple
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) modulation systems are possible. Contact the linux-media
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) mailing list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) if you need such functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) - ``reserved``\ [9]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) - Reserved for future extensions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) Applications and drivers must set the array to zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) .. _band-modulation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) .. flat-table:: Band Modulation Systems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) :header-rows: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) :stub-columns: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) :widths: 3 1 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * - ``V4L2_BAND_MODULATION_VSB``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) - 0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) - Vestigial Sideband modulation, used for analog TV.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * - ``V4L2_BAND_MODULATION_FM``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) - 0x04
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) - Frequency Modulation, commonly used for analog radio.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * - ``V4L2_BAND_MODULATION_AM``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) - 0x08
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) - Amplitude Modulation, commonly used for analog radio.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) Return Value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) ============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) On success 0 is returned, on error -1 and the ``errno`` variable is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) appropriately. The generic error codes are described at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) :ref:`Generic Error Codes <gen-errors>` chapter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) EINVAL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) The ``tuner`` or ``index`` is out of bounds or the ``type`` field is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) wrong.
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Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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