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media: fe_property_parameters.rst: better document bandwidth
Use a table to document the supported bandwidths. That makes it clearer to readers. Signed-off-by: Mauro Carvalho Chehab <[email protected]>
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Documentation/media/uapi/dvb/fe_property_parameters.rst

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@@ -116,29 +116,37 @@ Should be set only for terrestrial delivery systems.
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Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``,
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``8000000``, ``10000000``.
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.. note::
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======================= =======================================================
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Terrestrial Standard Possible values for bandwidth
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======================= =======================================================
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ATSC (version 1) No need to set. It is always 6MHz.
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DMTB No need to set. It is always 8MHz.
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DVB-T 6MHz, 7MHz and 8MHz.
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DVB-T2 1.172 MHz, 5MHz, 6MHz, 7MHz, 8MHz and 10MHz
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ISDB-T 5MHz, 6MHz, 7MHz and 8MHz, although most places
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use 6MHz.
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======================= =======================================================
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#. DVB-T supports 6, 7 and 8MHz.
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#. DVB-T2 supports 1.172, 5, 6, 7, 8 and 10MHz.
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.. note::
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#. ISDB-T supports 5MHz, 6MHz, 7MHz and 8MHz, although most
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places use 6MHz.
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#. On DVB-C and DVB-S/S2, the bandwidth depends on the symbol rate.
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So, the Kernel will silently ignore setting :ref:`DTV-BANDWIDTH-HZ`.
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#. For ISDB-Tsb, the bandwidth can vary depending on the number of
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connected segments.
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#. For DVB-C and DVB-S/S2, the Kernel will return an estimation of the
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bandwidth, calculated from :ref:`DTV-SYMBOL-RATE` and from
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the rolloff, with is fixed for DVB-C and DVB-S.
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It can be easily derived from other parameters
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(DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).
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#. For DVB-S2, the bandwidth estimation will use :ref:`DTV-ROLLOFF`.
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#. On Satellite and Cable delivery systems, the bandwidth depends on
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the symbol rate. So, the Kernel will silently ignore any setting
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:ref:`DTV-BANDWIDTH-HZ`. I will however fill it back with a
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bandwidth estimation.
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#. For ISDB-Tsb, it can vary depending on the number of connected
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segments.
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Such bandwidth estimation takes into account the symbol rate set with
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:ref:`DTV-SYMBOL-RATE`, and the rolloff factor, with is fixed for
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DVB-C and DVB-S.
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#. Bandwidth in ISDB-Tsb can be easily derived from other parameters
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(DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).
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For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`.
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.. _DTV-INVERSION:

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