diff --git a/Documentation/media/uapi/dvb/fe_property_parameters.rst b/Documentation/media/uapi/dvb/fe_property_parameters.rst index e085e84fef38..49470f7dda02 100644 --- a/Documentation/media/uapi/dvb/fe_property_parameters.rst +++ b/Documentation/media/uapi/dvb/fe_property_parameters.rst @@ -116,30 +116,38 @@ Should be set only for terrestrial delivery systems. Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``, ``8000000``, ``10000000``. +======================= ======================================================= +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. +======================= ======================================================= + + .. note:: - #. DVB-T supports 6, 7 and 8MHz. - #. DVB-T2 supports 1.172, 5, 6, 7, 8 and 10MHz. + #. For ISDB-Tsb, the bandwidth can vary depending on the number of + connected segments. - #. 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 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. - - #. For DVB-S2, the bandwidth estimation will use :ref:`DTV-ROLLOFF`. - - #. For ISDB-Tsb, it can vary depending on the number of connected - segments. - - #. Bandwidth in ISDB-Tsb can be easily derived from other parameters + It can be easily derived from other parameters (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT). + #. 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. + + 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. + + For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`. + .. _DTV-INVERSION: