media: fe_property_parameters.rst: better document bandwidth

Use a table to document the supported bandwidths. That makes it clearer to readers.

Mauro Carvalho Chehab committed 9 years ago

Commit 7d661ed1 parent 11814151 file · +23 −15Browse files

Unified · Split

Documentation/media/uapi/dvb/fe_property_parameters.rst+23−15

@@ -116,29 +116,37 @@ Should be set only for terrestrial delivery systems. · 115 unmodified lines
116	116	Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``,
117	117	``8000000``, ``10000000``.
118	118
119		−.. note::
	119	+======================= =======================================================
	120	+Terrestrial Standard Possible values for bandwidth
	121	+======================= =======================================================
	122	+ATSC (version 1) No need to set. It is always 6MHz.
	123	+DMTB No need to set. It is always 8MHz.
	124	+DVB-T 6MHz, 7MHz and 8MHz.
	125	+DVB-T2 1.172 MHz, 5MHz, 6MHz, 7MHz, 8MHz and 10MHz
	126	+ISDB-T 5MHz, 6MHz, 7MHz and 8MHz, although most places
	127	+ use 6MHz.
	128	+======================= =======================================================
120	129
121		− #. DVB-T supports 6, 7 and 8MHz.
122	130
123		− #. DVB-T2 supports 1.172, 5, 6, 7, 8 and 10MHz.
	131	+.. note::
124	132
125		− #. ISDB-T supports 5MHz, 6MHz, 7MHz and 8MHz, although most
126		− places use 6MHz.
127	133
128		− #. On DVB-C and DVB-S/S2, the bandwidth depends on the symbol rate.
129		− So, the Kernel will silently ignore setting :ref:`DTV-BANDWIDTH-HZ`.
	134	+ #. For ISDB-Tsb, the bandwidth can vary depending on the number of
	135	+ connected segments.
130	136
131		− #. For DVB-C and DVB-S/S2, the Kernel will return an estimation of the
132		− bandwidth, calculated from :ref:`DTV-SYMBOL-RATE` and from
133		− the rolloff, with is fixed for DVB-C and DVB-S.
	137	+ It can be easily derived from other parameters
	138	+ (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).
134	139
135		− #. For DVB-S2, the bandwidth estimation will use :ref:`DTV-ROLLOFF`.
	140	+ #. On Satellite and Cable delivery systems, the bandwidth depends on
	141	+ the symbol rate. So, the Kernel will silently ignore any setting
	142	+ :ref:`DTV-BANDWIDTH-HZ`. I will however fill it back with a
	143	+ bandwidth estimation.
136	144
137		− #. For ISDB-Tsb, it can vary depending on the number of connected
138		− segments.
	145	+ Such bandwidth estimation takes into account the symbol rate set with
	146	+ :ref:`DTV-SYMBOL-RATE`, and the rolloff factor, with is fixed for
	147	+ DVB-C and DVB-S.
139	148
140		− #. Bandwidth in ISDB-Tsb can be easily derived from other parameters
141		− (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).
	149	+ For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`.
142	150
143	151
144	152	.. _DTV-INVERSION: