From 7d661edd0daf91cceafc72dc5b4fa0b20317239d Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 31 Aug 2017 07:17:21 -0400 Subject: [PATCH] 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 --- .../media/uapi/dvb/fe_property_parameters.rst | 38 +++++++++++-------- 1 file changed, 23 insertions(+), 15 deletions(-) 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 @@ -116,29 +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: -- 2.20.1