.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
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*************
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Frontend type
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*************
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For historical reasons, frontend types are named by the type of
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modulation used in transmission. The fontend types are given by
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fe_type_t type, defined as:
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.. c:type:: fe_type
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.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
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.. flat-table:: Frontend types
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:header-rows: 1
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:stub-columns: 0
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:widths: 3 1 4
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- .. row 1
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- fe_type
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- Description
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- :ref:`DTV_DELIVERY_SYSTEM <DTV-DELIVERY-SYSTEM>` equivalent
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type
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- .. row 2
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- .. _FE-QPSK:
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``FE_QPSK``
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- For DVB-S standard
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- ``SYS_DVBS``
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- .. row 3
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- .. _FE-QAM:
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``FE_QAM``
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- For DVB-C annex A standard
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- ``SYS_DVBC_ANNEX_A``
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- .. row 4
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- .. _FE-OFDM:
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``FE_OFDM``
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- For DVB-T standard
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- ``SYS_DVBT``
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- .. row 5
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- .. _FE-ATSC:
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``FE_ATSC``
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- For ATSC standard (terrestrial) or for DVB-C Annex B (cable) used
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in US.
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- ``SYS_ATSC`` (terrestrial) or ``SYS_DVBC_ANNEX_B`` (cable)
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Newer formats like DVB-S2, ISDB-T, ISDB-S and DVB-T2 are not described
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at the above, as they're supported via the new
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:ref:`FE_GET_PROPERTY/FE_GET_SET_PROPERTY <FE_GET_PROPERTY>`
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ioctl's, using the :ref:`DTV_DELIVERY_SYSTEM <DTV-DELIVERY-SYSTEM>`
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parameter.
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In the old days, struct :c:type:`dvb_frontend_info`
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used to contain ``fe_type_t`` field to indicate the delivery systems,
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filled with either ``FE_QPSK, FE_QAM, FE_OFDM`` or ``FE_ATSC``. While this
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is still filled to keep backward compatibility, the usage of this field
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is deprecated, as it can report just one delivery system, but some
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devices support multiple delivery systems. Please use
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:ref:`DTV_ENUM_DELSYS <DTV-ENUM-DELSYS>` instead.
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On devices that support multiple delivery systems, struct
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:c:type:`dvb_frontend_info`::``fe_type_t`` is
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filled with the currently standard, as selected by the last call to
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:ref:`FE_SET_PROPERTY <FE_GET_PROPERTY>` using the
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:ref:`DTV_DELIVERY_SYSTEM <DTV-DELIVERY-SYSTEM>` property.
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