specification is available at
<ulink url="http://www.eutelsat.com/satellites/4_5_5.html">Eutelsat</ulink>.</para>
-
<section id="query-dvb-frontend-info">
<title>Querying frontend information</title>
-<para>Information about the frontend can be queried with
- <link linkend="FE_GET_INFO">FE_GET_INFO</link>.</para>
+<para>Usually, the first thing to do when the frontend is opened is to
+ check the frontend capabilities. This is done using <link linkend="FE_GET_INFO">FE_GET_INFO</link>. This ioctl will enumerate
+ the DVB API version and other characteristics about the frontend, and
+ can be opened either in read only or read/write mode.</para>
</section>
-&sub-fe-get-info;
-
<section id="dvb-fe-read-status">
-<title>Querying frontend status</title>
-
-<para>Information about the frontend tuner locking status can be queried with
- <link linkend="FE_READ_STATUS">FE_READ_STATUS</link>.</para>
+<title>Querying frontend status and statistics</title>
+
+<para>Once <link linkend="FE_GET_PROPERTY"><constant>FE_SET_PROPERTY</constant></link>
+ is called, the frontend will run a kernel thread that will periodically
+ check for the tuner lock status and provide statistics about the quality
+ of the signal.</para>
+<para>The information about the frontend tuner locking status can be queried
+ using <link linkend="FE_READ_STATUS">FE_READ_STATUS</link>.</para>
+<para>Signal statistics are provided via <link linkend="FE_GET_PROPERTY"><constant>FE_GET_PROPERTY</constant></link>.
+ Please notice that several statistics require the demodulator to be fully
+ locked (e. g. with FE_HAS_LOCK bit set). See
+ <xref linkend="frontend-stat-properties">Frontend statistics indicators</xref>
+ for more details.</para>
</section>
-&sub-fe-read-status;
-
&sub-dvbproperty;
-<section id="fe-spectral-inversion-t">
-<title>frontend spectral inversion</title>
-<para>The Inversion field can take one of these values:
-</para>
-<programlisting>
-typedef enum fe_spectral_inversion {
- INVERSION_OFF,
- INVERSION_ON,
- INVERSION_AUTO
-} fe_spectral_inversion_t;
-</programlisting>
-<para>It indicates if spectral inversion should be presumed or not. In the automatic setting
-(<constant>INVERSION_AUTO</constant>) the hardware will try to figure out the correct setting by
-itself.
-</para>
-</section>
-
-<section id="fe-code-rate-t">
-<title>frontend code rate</title>
-<para>The possible values for the <constant>fec_inner</constant> field used on
-<link linkend="dvb-qpsk-parameters"><constant>struct dvb_qpsk_parameters</constant></link> and
-<link linkend="dvb-qam-parameters"><constant>struct dvb_qam_parameters</constant></link> are:
-</para>
-<programlisting>
-typedef enum fe_code_rate {
- FEC_NONE = 0,
- FEC_1_2,
- FEC_2_3,
- FEC_3_4,
- FEC_4_5,
- FEC_5_6,
- FEC_6_7,
- FEC_7_8,
- FEC_8_9,
- FEC_AUTO,
- FEC_3_5,
- FEC_9_10,
-} fe_code_rate_t;
-</programlisting>
-<para>which correspond to error correction rates of 1/2, 2/3, etc., no error correction or auto
-detection.
-</para>
-</section>
-
-<section id="fe-modulation-t">
-<title>frontend modulation type for QAM, OFDM and VSB</title>
-<para>For cable and terrestrial frontends, e. g. for
-<link linkend="dvb-qam-parameters"><constant>struct dvb_qpsk_parameters</constant></link>,
-<link linkend="dvb-ofdm-parameters"><constant>struct dvb_qam_parameters</constant></link> and
-<link linkend="dvb-vsb-parameters"><constant>struct dvb_qam_parameters</constant></link>,
-it needs to specify the quadrature modulation mode which can be one of the following:
-</para>
-<programlisting>
- typedef enum fe_modulation {
- QPSK,
- QAM_16,
- QAM_32,
- QAM_64,
- QAM_128,
- QAM_256,
- QAM_AUTO,
- VSB_8,
- VSB_16,
- PSK_8,
- APSK_16,
- APSK_32,
- DQPSK,
- } fe_modulation_t;
-</programlisting>
-</section>
-
<section>
<title>More OFDM parameters</title>
-<section id="fe-transmit-mode-t">
-<title>Number of carriers per channel</title>
-<programlisting>
-typedef enum fe_transmit_mode {
- TRANSMISSION_MODE_2K,
- TRANSMISSION_MODE_8K,
- TRANSMISSION_MODE_AUTO,
- TRANSMISSION_MODE_4K,
- TRANSMISSION_MODE_1K,
- TRANSMISSION_MODE_16K,
- TRANSMISSION_MODE_32K,
- } fe_transmit_mode_t;
-</programlisting>
-</section>
-
-<section id="fe-bandwidth-t">
-<title>frontend bandwidth</title>
-<programlisting>
-typedef enum fe_bandwidth {
- BANDWIDTH_8_MHZ,
- BANDWIDTH_7_MHZ,
- BANDWIDTH_6_MHZ,
- BANDWIDTH_AUTO,
- BANDWIDTH_5_MHZ,
- BANDWIDTH_10_MHZ,
- BANDWIDTH_1_712_MHZ,
-} fe_bandwidth_t;
-</programlisting>
-</section>
-
-<section id="fe-guard-interval-t">
-<title>frontend guard inverval</title>
-<programlisting>
-typedef enum fe_guard_interval {
- GUARD_INTERVAL_1_32,
- GUARD_INTERVAL_1_16,
- GUARD_INTERVAL_1_8,
- GUARD_INTERVAL_1_4,
- GUARD_INTERVAL_AUTO,
- GUARD_INTERVAL_1_128,
- GUARD_INTERVAL_19_128,
- GUARD_INTERVAL_19_256,
-} fe_guard_interval_t;
-</programlisting>
-</section>
-
<section id="fe-hierarchy-t">
<title>frontend hierarchy</title>
<programlisting>
</row></tbody></tgroup></informaltable>
</section>
+&sub-fe-get-info;
+&sub-fe-read-status;
+&sub-fe-get-property;
&sub-fe-diseqc-reset-overload;
&sub-fe-diseqc-send-master-cmd;
&sub-fe-diseqc-recv-slave-reply;
projects / cascardo / linux.git / blobdiff