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[media] DocBook: Improve DVB frontend description

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The DVB frontend API got bitrotten. Update it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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Mauro Carvalho Chehab 2015-05-25 14:24:38 -03:00
parent 0b0f1a0056
commit ee072ed7e3
1 changed files with 28 additions and 16 deletions
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44
Documentation/DocBook/media/dvb/frontend.xml
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@ -1,30 +1,42 @@
<title>DVB Frontend API</title>
<para>The DVB frontend device controls the tuner and DVB demodulator
hardware. It can be accessed through <emphasis
role="bold">/dev/dvb/adapter0/frontend0</emphasis>. Data types and and
ioctl definitions can be accessed by including <emphasis
role="bold">linux/dvb/frontend.h</emphasis> in your application.</para>
<para>The DVB frontend API was designed to support three types of delivery systems:</para>
<itemizedlist>
<listitem>Terrestrial systems: DVB-T, DVB-T2, ATSC, ATSC M/H, ISDB-T, DVB-H, DTMB, CMMB</listitem>
<listitem>Cable systems: DVB-C Annex A/C, ClearQAM (DVB-C Annex B), ISDB-C</listitem>
<listitem>Satellital systems: DVB-S, DVB-S2, DVB Turbo, ISDB-S, DSS</listitem>
</itemizedlist>
<para>The DVB frontend controls several sub-devices including:</para>
<itemizedlist>
<listitem>Tuner</listitem>,
<listitem>Digital TV demodulator</listitem>
<listitem>Low noise amplifier (LNA)</listitem>
<listitem>Satellite Equipment Control (SEC) hardware (only for Satellite).</listitem>
</itemizedlist>
<para>The frontend can be accessed through
<emphasis role="bold">/dev/dvb/adapter?/frontend?</emphasis>. Data types and
ioctl definitions can be accessed by including
<emphasis role="bold">linux/dvb/frontend.h</emphasis> in your application.
</para>
<para>DVB frontends come in three varieties: DVB-S (satellite), DVB-C
(cable) and DVB-T (terrestrial). Transmission via the internet (DVB-IP)
is not yet handled by this API but a future extension is possible. For
DVB-S the frontend device also supports satellite equipment control
(SEC) via DiSEqC and V-SEC protocols. The DiSEqC (digital SEC)
specification is available from
<para>NOTE: Transmission via the internet (DVB-IP)
is not yet handled by this API but a future extension is possible.</para>
<para>On Satellital systems, the API support for the Satellite Equipment Control
(SEC) allows to power control and to send/receive signals to control the
antenna subsystem, selecting the polarization and choosing the Intermediate
Frequency IF) of the Low Noise Block Converter Feed Horn (LNBf). It
supports the DiSEqC and V-SEC protocols. The DiSEqC (digital SEC)
specification is available at
<ulink url="http://www.eutelsat.com/satellites/4_5_5.html">Eutelsat</ulink>.</para>
<para>Note that the DVB API may also be used for MPEG decoder-only PCI
cards, in which case there exists no frontend device.</para>
<section id="frontend_types">
<title>Frontend Data Types</title>
<section id="fe-type-t">
<title>Frontend type</title>
<para>For historical reasons, frontend types are named by the type of modulation used in
transmission. The fontend types are given by fe_type_t type, defined as:</para>
<para>For historical reasons, frontend types are named by the type of modulation
used in transmission. The fontend types are given by fe_type_t type, defined as:</para>
<table pgwide="1" frame="none" id="fe-type">
<title>Frontend types</title>