Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7d661edd authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

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: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 1181415d

Documentation/media/uapi/dvb/fe_property_parameters.rst

+23 −15
Original line number Diff line number Diff line
@@ -116,29 +116,37 @@ Should be set only for terrestrial delivery systems. 
Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``,

``8000000``, ``10000000``.



.. note::

======================= =======================================================

Terrestrial Standard	Possible values for bandwidth

======================= =======================================================

ATSC (version 1)	No need to set. It is always 6MHz.

DMTB			No need to set. It is always 8MHz.

DVB-T			6MHz, 7MHz and 8MHz.

DVB-T2			1.172 MHz, 5MHz, 6MHz, 7MHz, 8MHz and 10MHz

ISDB-T			5MHz, 6MHz, 7MHz and 8MHz, although most places

			use 6MHz.

======================= =======================================================



  #. DVB-T supports 6, 7 and 8MHz.



  #. DVB-T2 supports 1.172, 5, 6, 7, 8 and 10MHz.

.. note::



  #. ISDB-T supports 5MHz, 6MHz, 7MHz and 8MHz, although most

     places use 6MHz.



  #. On DVB-C and DVB-S/S2, the bandwidth depends on the symbol rate.

     So, the Kernel will silently ignore setting :ref:`DTV-BANDWIDTH-HZ`.

  #. For ISDB-Tsb, the bandwidth can vary depending on the number of

     connected segments.



  #. For DVB-C and DVB-S/S2, the Kernel will return an estimation of the

     bandwidth, calculated from :ref:`DTV-SYMBOL-RATE` and from

     the rolloff, with is fixed for DVB-C and DVB-S.

     It can be easily derived from other parameters

     (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).



  #. For DVB-S2, the bandwidth estimation will use :ref:`DTV-ROLLOFF`.

  #. On Satellite and Cable delivery systems, the bandwidth depends on

     the symbol rate. So, the Kernel will silently ignore any setting

     :ref:`DTV-BANDWIDTH-HZ`. I will however fill it back with a

     bandwidth estimation.



  #. For ISDB-Tsb, it can vary depending on the number of connected

     segments.

     Such bandwidth estimation takes into account the symbol rate set with

     :ref:`DTV-SYMBOL-RATE`, and the rolloff factor, with is fixed for

     DVB-C and DVB-S.



  #. Bandwidth in ISDB-Tsb can be easily derived from other parameters

     (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).

     For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`.





.. _DTV-INVERSION: