path: root/Documentation/DocBook/media/dvb/dvbproperty.xml
diff options
Diffstat (limited to 'Documentation/DocBook/media/dvb/dvbproperty.xml')
1 files changed, 22 insertions, 9 deletions
diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml
index 3bc8a61efe3..c7a4ca51785 100644
--- a/Documentation/DocBook/media/dvb/dvbproperty.xml
+++ b/Documentation/DocBook/media/dvb/dvbproperty.xml
@@ -163,14 +163,16 @@ get/set up to 64 properties. The actual meaning of each property is described on
<section id="DTV-FREQUENCY">
- <para>Central frequency of the channel, in HZ.</para>
+ <para>Central frequency of the channel.</para>
- <para>1)For ISDB-T, the channels are usually transmitted with an offset of 143kHz.
+ <para>1)For satellital delivery systems, it is measured in kHz.
+ For the other ones, it is measured in Hz.</para>
+ <para>2)For ISDB-T, the channels are usually transmitted with an offset of 143kHz.
E.g. a valid frequncy could be 474143 kHz. The stepping is bound to the bandwidth of
the channel which is 6MHz.</para>
- <para>2)As in ISDB-Tsb the channel consists of only one or three segments the
+ <para>3)As in ISDB-Tsb the channel consists of only one or three segments the
frequency step is 429kHz, 3*429 respectively. As for ISDB-T the
central frequency of the channel is expected.</para>
@@ -334,9 +336,10 @@ typedef enum fe_rolloff {
<title>fe_delivery_system type</title>
<para>Possible values: </para>
typedef enum fe_delivery_system {
@@ -353,6 +356,7 @@ typedef enum fe_delivery_system {
} fe_delivery_system_t;
@@ -647,6 +651,18 @@ typedef enum fe_hierarchy {
many data types via a single multiplex. The API will soon support this
at which point this section will be expanded.</para>
+ <section id="DTV_ENUM_DELSYS">
+ <title><constant>DTV_ENUM_DELSYS</constant></title>
+ <para>A Multi standard frontend needs to advertise the delivery systems provided.
+ Applications need to enumerate the provided delivery systems, before using
+ any other operation with the frontend. Prior to it's introduction,
+ FE_GET_INFO was used to determine a frontend type. A frontend which
+ provides more than a single delivery system, FE_GET_INFO doesn't help much.
+ Applications which intends to use a multistandard frontend must enumerate
+ the delivery systems associated with it, rather than trying to use
+ FE_GET_INFO. In the case of a legacy frontend, the result is just the same
+ as with FE_GET_INFO, but in a more structured format </para>
+ </section>
<section id="frontend-property-terrestrial-systems">
<title>Properties used on terrestrial delivery systems</title>
@@ -721,14 +737,10 @@ typedef enum fe_hierarchy {
<listitem><para><link linkend="DTV-TUNE"><constant>DTV_TUNE</constant></link></para></listitem>
<listitem><para><link linkend="DTV-CLEAR"><constant>DTV_CLEAR</constant></link></para></listitem>
<listitem><para><link linkend="DTV-FREQUENCY"><constant>DTV_FREQUENCY</constant></link></para></listitem>
- <listitem><para><link linkend="DTV-MODULATION"><constant>DTV_MODULATION</constant></link></para></listitem>
<listitem><para><link linkend="DTV-BANDWIDTH-HZ"><constant>DTV_BANDWIDTH_HZ</constant></link></para></listitem>
<listitem><para><link linkend="DTV-INVERSION"><constant>DTV_INVERSION</constant></link></para></listitem>
- <listitem><para><link linkend="DTV-CODE-RATE-HP"><constant>DTV_CODE_RATE_HP</constant></link></para></listitem>
- <listitem><para><link linkend="DTV-CODE-RATE-LP"><constant>DTV_CODE_RATE_LP</constant></link></para></listitem>
<listitem><para><link linkend="DTV-GUARD-INTERVAL"><constant>DTV_GUARD_INTERVAL</constant></link></para></listitem>
<listitem><para><link linkend="DTV-TRANSMISSION-MODE"><constant>DTV_TRANSMISSION_MODE</constant></link></para></listitem>
- <listitem><para><link linkend="DTV-HIERARCHY"><constant>DTV_HIERARCHY</constant></link></para></listitem>
<listitem><para><link linkend="DTV-ISDBT-LAYER-ENABLED"><constant>DTV_ISDBT_LAYER_ENABLED</constant></link></para></listitem>
<listitem><para><link linkend="DTV-ISDBT-PARTIAL-RECEPTION"><constant>DTV_ISDBT_PARTIAL_RECEPTION</constant></link></para></listitem>
<listitem><para><link linkend="DTV-ISDBT-SOUND-BROADCASTING"><constant>DTV_ISDBT_SOUND_BROADCASTING</constant></link></para></listitem>
@@ -767,7 +779,8 @@ typedef enum fe_hierarchy {
<title>Properties used on cable delivery systems</title>
<section id="dvbc-params">
<title>DVB-C delivery system</title>
- <para>The DVB-C Annex-A/C is the widely used cable standard. Transmission uses QAM modulation.</para>
+ <para>The DVB-C Annex-A is the widely used cable standard. Transmission uses QAM modulation.</para>
+ <para>The DVB-C Annex-C is optimized for 6MHz, and is used in Japan. It supports a subset of the Annex A modulation types, and a roll-off of 0.13, instead of 0.15</para>
<para>The following parameters are valid for DVB-C Annex A/C:</para>
<itemizedlist mark='opencircle'>
<listitem><para><link linkend="DTV-API-VERSION"><constant>DTV_API_VERSION</constant></link></para></listitem>