path: root/Documentation/DocBook/media/dvb/dvbproperty.xml

<section id="FE_GET_SET_PROPERTY">
<title>FE_GET_PROPERTY/FE_SET_PROPERTY</title>

<programlisting>
/* Reserved fields should be set to 0 */
struct dtv_property {
	__u32 cmd;
	union {
		__u32 data;
		struct {
			__u8 data[32];
			__u32 len;
			__u32 reserved1[3];
			void *reserved2;
		} buffer;
	} u;
	int result;
} __attribute__ ((packed));

/* num of properties cannot exceed DTV_IOCTL_MAX_MSGS per ioctl */
#define DTV_IOCTL_MAX_MSGS 64

struct dtv_properties {
	__u32 num;
	struct dtv_property *props;
};
</programlisting>

<section id="FE_GET_PROPERTY">
<title>FE_GET_PROPERTY</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call returns one or more frontend properties. This call only
 requires read-only access to the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link>,
 dtv_properties &#x22C6;props);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int num</para>
</entry><entry
 align="char">
<para>Equals <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link> for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct dtv_property *props</para>
</entry><entry
 align="char">
<para>Points to the location where the front-end property commands are stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>ERRORS</para>
<informaltable><tgroup cols="2"><tbody><row>
  <entry align="char"><para>EINVAL</para></entry>
  <entry align="char"><para>Invalid parameter(s) received or number of parameters out of the range.</para></entry>
 </row><row>
  <entry align="char"><para>ENOMEM</para></entry>
  <entry align="char"><para>Out of memory.</para></entry>
 </row><row>
  <entry align="char"><para>EFAULT</para></entry>
  <entry align="char"><para>Failure while copying data from/to userspace.</para></entry>
 </row><row>
  <entry align="char"><para>EOPNOTSUPP</para></entry>
  <entry align="char"><para>Property type not supported.</para></entry>
 </row></tbody></tgroup></informaltable>
</section>

<section id="FE_SET_PROPERTY">
<title>FE_SET_PROPERTY</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call sets one or more frontend properties. This call only
 requires read-only access to the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = <link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link>,
 dtv_properties &#x22C6;props);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int num</para>
</entry><entry
 align="char">
<para>Equals <link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link> for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct dtv_property *props</para>
</entry><entry
 align="char">
<para>Points to the location where the front-end property commands are stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row>
  <entry align="char"><para>EINVAL</para></entry>
  <entry align="char"><para>Invalid parameter(s) received or number of parameters out of the range.</para></entry>
 </row><row>
  <entry align="char"><para>ENOMEM</para></entry>
  <entry align="char"><para>Out of memory.</para></entry>
 </row><row>
  <entry align="char"><para>EFAULT</para></entry>
  <entry align="char"><para>Failure while copying data from/to userspace.</para></entry>
 </row><row>
  <entry align="char"><para>EOPNOTSUPP</para></entry>
  <entry align="char"><para>Property type not supported.</para></entry>
 </row></tbody></tgroup></informaltable>
</section>

<section>
	<title>Property types</title>
<para>
On <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link>/<link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link>,
the actual action is determined by the dtv_property cmd/data pairs. With one single ioctl, is possible to
get/set up to 64 properties. The actual meaning of each property is described on the next sections.
</para>

<para>The available frontend property types are:</para>

<para><link linkend="DTV-UNDEFINED">DTV_UNDEFINED</link></para>
<para><link linkend="DTV-TUNE">DTV_TUNE</link></para>
<para><link linkend="DTV-CLEAR">DTV_CLEAR</link></para>
<para><link linkend="DTV-FREQUENCY">DTV_FREQUENCY</link></para>
<para><link linkend="DTV-MODULATION">DTV_MODULATION</link></para>
<para><link linkend="DTV-BANDWIDTH-HZ">DTV_BANDWIDTH_HZ</link></para>
<para><link linkend="DTV-INVERSION">DTV_INVERSION</link></para>
<para><link linkend="DTV-DISEQC-MASTER">DTV_DISEQC_MASTER</link></para>
<para><link linkend="DTV-SYMBOL-RATE">DTV_SYMBOL_RATE</link></para>
<para><link linkend="DTV-INNER-FEC">DTV_INNER_FEC</link></para>
<para><link linkend="DTV-VOLTAGE">DTV_VOLTAGE</link></para>
<para><link linkend="DTV-TONE">DTV_TONE</link></para>
<para><link linkend="DTV-PILOT">DTV_PILOT</link></para>
<para><link linkend="DTV-ROLLOFF">DTV_ROLLOFF</link></para>
<para><link linkend="DTV-DISEQC-SLAVE-REPLY">DTV_DISEQC_SLAVE_REPLY</link></para>
<para><link linkend="DTV-FE-CAPABILITY-COUNT">DTV_FE_CAPABILITY_COUNT</link></para>
<para><link linkend="DTV-FE-CAPABILITY">DTV_FE_CAPABILITY</link></para>
<para><link linkend="DTV-DELIVERY-SYSTEM">DTV_DELIVERY_SYSTEM</link></para>
<para><link linkend="DTV-ISDBT-PARTIAL-RECEPTION">DTV_ISDBT_PARTIAL_RECEPTION</link></para>
<para><link linkend="DTV-ISDBT-SOUND-BROADCASTING">DTV_ISDBT_SOUND_BROADCASTING</link></para>
<para><link linkend="DTV-ISDBT-SB-SUBCHANNEL-ID">DTV_ISDBT_SB_SUBCHANNEL_ID</link></para>
<para><link linkend="DTV-ISDBT-SB-SEGMENT-IDX">DTV_ISDBT_SB_SEGMENT_IDX</link></para>
<para><link linkend="DTV-ISDBT-SB-SEGMENT-COUNT">DTV_ISDBT_SB_SEGMENT_COUNT</link></para>
<para><link linkend="DTV-ISDBT-LAYER-FEC">DTV_ISDBT_LAYERA_FEC</link></para>
<para><link linkend="DTV-ISDBT-LAYER-MODULATION">DTV_ISDBT_LAYERA_MODULATION</link></para>
<para><link linkend="DTV-ISDBT-LAYER-SEGMENT-COUNT">DTV_ISDBT_LAYERA_SEGMENT_COUNT</link></para>
<para><link linkend="DTV-ISDBT-LAYER-TIME-INTERLEAVING">DTV_ISDBT_LAYERA_TIME_INTERLEAVING</link></para>
<para><link linkend="DTV-ISDBT-LAYER-FEC">DTV_ISDBT_LAYERB_FEC</link></para>
<para><link linkend="DTV-ISDBT-LAYER-MODULATION">DTV_ISDBT_LAYERB_MODULATION</link></para>
<para><link linkend="DTV-ISDBT-LAYER-SEGMENT-COUNT">DTV_ISDBT_LAYERB_SEGMENT_COUNT</link></para>
<para><link linkend="DTV-ISDBT-LAYER-TIME-INTERLEAVING">DTV_ISDBT_LAYERB_TIME_INTERLEAVING</link></para>
<para><link linkend="DTV-ISDBT-LAYER-FEC">DTV_ISDBT_LAYERC_FEC</link></para>
<para><link linkend="DTV-ISDBT-LAYER-MODULATION">DTV_ISDBT_LAYERC_MODULATION</link></para>
<para><link linkend="DTV-ISDBT-LAYER-SEGMENT-COUNT">DTV_ISDBT_LAYERC_SEGMENT_COUNT</link></para>
<para><link linkend="DTV-ISDBT-LAYER-TIME-INTERLEAVING">DTV_ISDBT_LAYERC_TIME_INTERLEAVING</link></para>
<para><link linkend="DTV-API-VERSION">DTV_API_VERSION</link></para>
<para><link linkend="DTV-CODE-RATE-HP">DTV_CODE_RATE_HP</link></para>
<para><link linkend="DTV-CODE-RATE-LP">DTV_CODE_RATE_LP</link></para>
<para><link linkend="DTV-GUARD-INTERVAL">DTV_GUARD_INTERVAL</link></para>
<para><link linkend="DTV-TRANSMISSION-MODE">DTV_TRANSMISSION_MODE</link></para>
<para><link linkend="DTV-HIERARCHY">DTV_HIERARCHY</link></para>
<para><link linkend="DTV-ISDBT-LAYER-ENABLED">DTV_ISDBT_LAYER_ENABLED</link></para>
<para><link linkend="DTV-ISDBS-TS-ID">DTV_ISDBS_TS_ID</link></para>
<para><link linkend="DTV-DVBT2-PLP-ID">DTV_DVBT2_PLP_ID</link></para>
</section>

<section id="fe_property_common">
	<title>Parameters that are common to all Digital TV standards</title>
	<section id="DTV-UNDEFINED">
	<title><constant>DTV_UNDEFINED</constant></title>
	<para>Used internally. A GET/SET operation for it won't change or return anything.</para>
	</section>
	<section id="DTV-TUNE">
	<title><constant>DTV_TUNE</constant></title>
	<para>Interpret the cache of data, build either a traditional frontend tunerequest so we can pass validation in the <constant>FE_SET_FRONTEND</constant> ioctl.</para>
	</section>
	<section id="DTV-CLEAR">
	<title><constant>DTV_CLEAR</constant></title>
	<para>Reset a cache of data specific to the frontend here. This does not effect hardware.</para>
	</section>
	<section id="DTV-MODULATION">
	<title><constant>DTV_MODULATION</constant></title>
<para>Specifies the frontend modulation type for cable and satellite types. The modulation can be one of the types bellow:</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 id="DTV-INVERSION">
	<title><constant>DTV_INVERSION</constant></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="DTV-DISEQC-MASTER">
	<title><constant>DTV_DISEQC_MASTER</constant></title>
	<para>Currently not implemented.</para>
	</section>
	<section id="DTV-SYMBOL-RATE">
	<title><constant>DTV_SYMBOL_RATE</constant></title>
	<para>Digital TV symbol rate, in bauds (symbols/second). Used on cable standards.</para>
	</section>
	<section id="DTV-INNER-FEC">
	<title><constant>DTV_INNER_FEC</constant></title>
	<para>Used cable/satellite transmissions. The acceptable values 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="DTV-VOLTAGE">
	<title><constant>DTV_VOLTAGE</constant></title>
	<para>The voltage is usually used with non-DiSEqC capable LNBs to switch
	the polarzation (horizontal/vertical). When using DiSEqC epuipment this
	voltage has to be switched consistently to the DiSEqC commands as
	described in the DiSEqC spec.</para>
	<programlisting>
		typedef enum fe_sec_voltage {
		SEC_VOLTAGE_13,
		SEC_VOLTAGE_18
		} fe_sec_voltage_t;
	</programlisting>
	</section>
	<section id="DTV-TONE">
	<title><constant>DTV_TONE</constant></title>
	<para>Currently not used.</para>
	</section>
	<section id="DTV-PILOT">
	<title><constant>DTV_PILOT</constant></title>
	<para>Sets DVB-S2 pilot</para>
	<section id="fe-pilot-t">
		<title>fe_pilot type</title>
		<programlisting>
typedef enum fe_pilot {
	PILOT_ON,
	PILOT_OFF,
	PILOT_AUTO,
} fe_pilot_t;
		</programlisting>
		</section>
	</section>
	<section id="DTV-ROLLOFF">
	<title><constant>DTV_ROLLOFF</constant></title>
		<para>Sets DVB-S2 rolloff</para>

	<section id="fe-rolloff-t">
		<title>fe_rolloff type</title>
		<programlisting>
typedef enum fe_rolloff {
	ROLLOFF_35, /* Implied value in DVB-S, default for DVB-S2 */
	ROLLOFF_20,
	ROLLOFF_25,
	ROLLOFF_AUTO,
} fe_rolloff_t;
		</programlisting>
		</section>
	</section>
	<section id="DTV-DISEQC-SLAVE-REPLY">
	<title><constant>DTV_DISEQC_SLAVE_REPLY</constant></title>
	<para>Currently not implemented.</para>
	</section>
	<section id="DTV-FE-CAPABILITY-COUNT">
	<title><constant>DTV_FE_CAPABILITY_COUNT</constant></title>
	<para>Currently not implemented.</para>
	</section>
	<section id="DTV-FE-CAPABILITY">
	<title><constant>DTV_FE_CAPABILITY</constant></title>
	<para>Currently not implemented.</para>
	</section>
	<section id="DTV-API-VERSION">
	<title><constant>DTV_API_VERSION</constant></title>
	<para>Returns the major/minor version of the DVB API</para>
	</section>
	<section id="DTV-CODE-RATE-HP">
	<title><constant>DTV_CODE_RATE_HP</constant></title>
	<para>Used on terrestrial transmissions. The acceptable values 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>
	</section>
	<section id="DTV-CODE-RATE-LP">
	<title><constant>DTV_CODE_RATE_LP</constant></title>
	<para>Used on terrestrial transmissions. The acceptable values 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>
	</section>
	<section id="DTV-HIERARCHY">
	<title><constant>DTV_HIERARCHY</constant></title>
	<para>Frontend hierarchy</para>
	<programlisting>
typedef enum fe_hierarchy {
	 HIERARCHY_NONE,
	 HIERARCHY_1,
	 HIERARCHY_2,
	 HIERARCHY_4,
	 HIERARCHY_AUTO
 } fe_hierarchy_t;
	</programlisting>
	</section>
	<section id="DTV-ISDBS-TS-ID">
	<title><constant>DTV_ISDBS_TS_ID</constant></title>
	<para>Currently unused.</para>
	</section>
	<section id="DTV-FREQUENCY">
		<title><constant>DTV_FREQUENCY</constant></title>

		<para>Central frequency of the channel, in HZ.</para>

		<para>Notes:</para>
		<para>1)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
			frequency step is 429kHz, 3*429 respectively. As for ISDB-T the
			central frequency of the channel is expected.</para>
	</section>

	<section id="DTV-BANDWIDTH-HZ">
		<title><constant>DTV_BANDWIDTH_HZ</constant></title>

		<para>Bandwidth for the channel, in HZ.</para>

		<para>Possible values:
			<constant>1712000</constant>,
			<constant>5000000</constant>,
			<constant>6000000</constant>,
			<constant>7000000</constant>,
			<constant>8000000</constant>,
			<constant>10000000</constant>.
		</para>

		<para>Notes:</para>

		<para>1) For ISDB-T it should be always 6000000Hz (6MHz)</para>
		<para>2) For ISDB-Tsb it can vary depending on the number of connected segments</para>
		<para>3) Bandwidth doesn't apply for DVB-C transmissions, as the bandwidth
			 for DVB-C depends on the symbol rate</para>
		<para>4) Bandwidth in ISDB-T is fixed (6MHz) or can be easily derived from
			other parameters (DTV_ISDBT_SB_SEGMENT_IDX,
			DTV_ISDBT_SB_SEGMENT_COUNT).</para>
		<para>5) DVB-T supports 6, 7 and 8MHz.</para>
		<para>6) In addition, DVB-T2 supports 1.172, 5 and 10MHz.</para>
	</section>

	<section id="DTV-DELIVERY-SYSTEM">
		<title><constant>DTV_DELIVERY_SYSTEM</constant></title>

		<para>Specifies the type of Delivery system</para>

		<para>Possible values: </para>
<programlisting>
typedef enum fe_delivery_system {
	SYS_UNDEFINED,
	SYS_DVBC_ANNEX_AC,
	SYS_DVBC_ANNEX_B,
	SYS_DVBT,
	SYS_DSS,
	SYS_DVBS,
	SYS_DVBS2,
	SYS_DVBH,
	SYS_ISDBT,
	SYS_ISDBS,
	SYS_ISDBC,
	SYS_ATSC,
	SYS_ATSCMH,
	SYS_DMBTH,
	SYS_CMMB,
	SYS_DAB,
	SYS_DVBT2,
} fe_delivery_system_t;
</programlisting>

	</section>

	<section id="DTV-TRANSMISSION-MODE">
		<title><constant>DTV_TRANSMISSION_MODE</constant></title>

		<para>Specifies the number of carriers used by the standard</para>

		<para>Possible values are:</para>
<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>

		<para>Notes:</para>
		<para>1) ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
			'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K</para>

		<para>2) If <constant>DTV_TRANSMISSION_MODE</constant> is set the <constant>TRANSMISSION_MODE_AUTO</constant> the
			hardware will try to find the correct FFT-size (if capable) and will
			use TMCC to fill in the missing parameters.</para>
		<para>3) DVB-T specifies 2K and 8K as valid sizes.</para>
		<para>4) DVB-T2 specifies 1K, 2K, 4K, 8K, 16K and 32K.</para>
	</section>

	<section id="DTV-GUARD-INTERVAL">
		<title><constant>DTV_GUARD_INTERVAL</constant></title>

		<para>Possible values are:</para>
<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>

		<para>Notes:</para>
		<para>1) If <constant>DTV_GUARD_INTERVAL</constant> is set the <constant>GUARD_INTERVAL_AUTO</constant> the hardware will
			try to find the correct guard interval (if capable) and will use TMCC to fill
			in the missing parameters.</para>
		<para>2) Intervals 1/128, 19/128 and 19/256 are used only for DVB-T2 at present</para>
	</section>
</section>

<section id="isdbt">
	<title>ISDB-T frontend</title>
	<para>This section describes shortly what are the possible parameters in the Linux
		DVB-API called "S2API" and now DVB API 5 in order to tune an ISDB-T/ISDB-Tsb
		demodulator:</para>

	<para>This ISDB-T/ISDB-Tsb API extension should reflect all information
		needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible
		that some very sophisticated devices won't need certain parameters to
		tune.</para>

	<para>The information given here should help application writers to know how
		to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.</para>

	<para>The details given here about ISDB-T and ISDB-Tsb are just enough to
		basically show the dependencies between the needed parameter values,
		but surely some information is left out. For more detailed information
		see the following documents:</para>

	<para>ARIB STD-B31 - "Transmission System for Digital Terrestrial
		Television Broadcasting" and</para>
	<para>ARIB TR-B14 - "Operational Guidelines for Digital Terrestrial
		Television Broadcasting".</para>

	<para>In order to read this document one has to have some knowledge the
		channel structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to
		the reader that an ISDB-T channel consists of 13 segments, that it can
		have up to 3 layer sharing those segments, and things like that.</para>

	<para>Parameters used by ISDB-T and ISDB-Tsb.</para>

	<section id="isdbt-new-parms">
		<title>ISDB-T only parameters</title>

		<section id="DTV-ISDBT-PARTIAL-RECEPTION">
			<title><constant>DTV_ISDBT_PARTIAL_RECEPTION</constant></title>

			<para>If <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '0' this bit-field represents whether
				the channel is in partial reception mode or not.</para>

			<para>If '1' <constant>DTV_ISDBT_LAYERA_*</constant> values are assigned to the center segment and
				<constant>DTV_ISDBT_LAYERA_SEGMENT_COUNT</constant> has to be '1'.</para>

			<para>If in addition <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'
				<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> represents whether this ISDB-Tsb channel
				is consisting of one segment and layer or three segments and two layers.</para>

			<para>Possible values: 0, 1, -1 (AUTO)</para>
		</section>

		<section id="DTV-ISDBT-SOUND-BROADCASTING">
			<title><constant>DTV_ISDBT_SOUND_BROADCASTING</constant></title>

			<para>This field represents whether the other DTV_ISDBT_*-parameters are
				referring to an ISDB-T and an ISDB-Tsb channel. (See also
				<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>).</para>

			<para>Possible values: 0, 1, -1 (AUTO)</para>
		</section>

		<section id="DTV-ISDBT-SB-SUBCHANNEL-ID">
			<title><constant>DTV_ISDBT_SB_SUBCHANNEL_ID</constant></title>

			<para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>

			<para>(Note of the author: This might not be the correct description of the
				<constant>SUBCHANNEL-ID</constant> in all details, but it is my understanding of the technical
				background needed to program a device)</para>

			<para>An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
				set of connected ISDB-Tsb channels. In this set of channels every
				channel can be received independently. The number of connected
				ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum
				bandwidth available.</para>

			<para>Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
				broadcaster has several possibilities to put those channels in the
				air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8
				segments from position 1-8 to 5-13 or anything in between.</para>

			<para>The underlying layer of segments are subchannels: each segment is
				consisting of several subchannels with a predefined IDs. A sub-channel
				is used to help the demodulator to synchronize on the channel.</para>

			<para>An ISDB-T channel is always centered over all sub-channels. As for
				the example above, in ISDB-Tsb it is no longer as simple as that.</para>

			<para><constant>The DTV_ISDBT_SB_SUBCHANNEL_ID</constant> parameter is used to give the
				sub-channel ID of the segment to be demodulated.</para>

			<para>Possible values: 0 .. 41, -1 (AUTO)</para>
		</section>

		<section id="DTV-ISDBT-SB-SEGMENT-IDX">

			<title><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant></title>

			<para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>

			<para><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant> gives the index of the segment to be
				demodulated for an ISDB-Tsb channel where several of them are
				transmitted in the connected manner.</para>

			<para>Possible values: 0 .. <constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> - 1</para>

			<para>Note: This value cannot be determined by an automatic channel search.</para>
		</section>

		<section id="DTV-ISDBT-SB-SEGMENT-COUNT">
			<title><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant></title>

			<para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para>

			<para><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> gives the total count of connected ISDB-Tsb
				channels.</para>

			<para>Possible values: 1 .. 13</para>

			<para>Note: This value cannot be determined by an automatic channel search.</para>
		</section>

		<section id="isdb-hierq-layers">
			<title>Hierarchical layers</title>

			<para>ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
				ISDB-T hierarchical layers can be decoded simultaneously. For that
				reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.</para>

			<para>ISDB-T has 3 hierarchical layers which each can use a part of the
				available segments. The total number of segments over all layers has
				to 13 in ISDB-T.</para>

			<section id="DTV-ISDBT-LAYER-ENABLED">
				<title><constant>DTV_ISDBT_LAYER_ENABLED</constant></title>

				<para>Hierarchical reception in ISDB-T is achieved by enabling or disabling
					layers in the decoding process. Setting all bits of
					<constant>DTV_ISDBT_LAYER_ENABLED</constant> to '1' forces all layers (if applicable) to be
					demodulated. This is the default.</para>

				<para>If the channel is in the partial reception mode
					(<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> = 1) the central segment can be decoded
					independently of the other 12 segments. In that mode layer A has to
					have a <constant>SEGMENT_COUNT</constant> of 1.</para>

				<para>In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb
					according to <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>. <constant>SEGMENT_COUNT</constant> must be filled
					accordingly.</para>

				<para>Possible values: 0x1, 0x2, 0x4 (|-able)</para>

				<para><constant>DTV_ISDBT_LAYER_ENABLED[0:0]</constant> - layer A</para>
				<para><constant>DTV_ISDBT_LAYER_ENABLED[1:1]</constant> - layer B</para>
				<para><constant>DTV_ISDBT_LAYER_ENABLED[2:2]</constant> - layer C</para>
				<para><constant>DTV_ISDBT_LAYER_ENABLED[31:3]</constant> unused</para>
			</section>

			<section id="DTV-ISDBT-LAYER-FEC">
				<title><constant>DTV_ISDBT_LAYER*_FEC</constant></title>

				<para>Possible values: <constant>FEC_AUTO</constant>, <constant>FEC_1_2</constant>, <constant>FEC_2_3</constant>, <constant>FEC_3_4</constant>, <constant>FEC_5_6</constant>, <constant>FEC_7_8</constant></para>
			</section>

			<section id="DTV-ISDBT-LAYER-MODULATION">
				<title><constant>DTV_ISDBT_LAYER*_MODULATION</constant></title>

				<para>Possible values: <constant>QAM_AUTO</constant>, QP<constant>SK, QAM_16</constant>, <constant>QAM_64</constant>, <constant>DQPSK</constant></para>

				<para>Note: If layer C is <constant>DQPSK</constant> layer B has to be <constant>DQPSK</constant>. If layer B is <constant>DQPSK</constant>
					and <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>=0 layer has to be <constant>DQPSK</constant>.</para>
			</section>

			<section id="DTV-ISDBT-LAYER-SEGMENT-COUNT">
				<title><constant>DTV_ISDBT_LAYER*_SEGMENT_COUNT</constant></title>

				<para>Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)</para>

				<para>Note: Truth table for <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> and
					<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> and <constant>LAYER</constant>*_SEGMENT_COUNT</para>

				<informaltable id="isdbt-layer_seg-cnt-table">
					<tgroup cols="6">

						<tbody>
							<row>
								<entry>PR</entry>
								<entry>SB</entry>
								<entry>Layer A width</entry>
								<entry>Layer B width</entry>
								<entry>Layer C width</entry>
								<entry>total width</entry>
							</row>

							<row>
								<entry>0</entry>
								<entry>0</entry>
								<entry>1 .. 13</entry>
								<entry>1 .. 13</entry>
								<entry>1 .. 13</entry>
								<entry>13</entry>
							</row>

							<row>
								<entry>1</entry>
								<entry>0</entry>
								<entry>1</entry>
								<entry>1 .. 13</entry>
								<entry>1 .. 13</entry>
								<entry>13</entry>
							</row>

							<row>
								<entry>0</entry>
								<entry>1</entry>
								<entry>1</entry>
								<entry>0</entry>
								<entry>0</entry>
								<entry>1</entry>
							</row>

							<row>
								<entry>1</entry>
								<entry>1</entry>
								<entry>1</entry>
								<entry>2</entry>
								<entry>0</entry>
								<entry>13</entry>
							</row>
						</tbody>

					</tgroup>
				</informaltable>

			</section>

			<section id="DTV-ISDBT-LAYER-TIME-INTERLEAVING">
				<title><constant>DTV_ISDBT_LAYER*_TIME_INTERLEAVING</constant></title>

				<para>Possible values: 0, 1, 2, 3, -1 (AUTO)</para>

				<para>Note: The real inter-leaver depth-names depend on the mode (fft-size); the values
					here are referring to what can be found in the TMCC-structure -
					independent of the mode.</para>
			</section>
		</section>
	</section>
	<section id="dvbt2-params">
		<title>DVB-T2 parameters</title>

		<para>This section covers parameters that apply only to the DVB-T2 delivery method. DVB-T2
			support is currently in the early stages development so expect this section to grow
			and become more detailed with time.</para>

		<section id="DTV-DVBT2-PLP-ID">
			<title><constant>DTV_DVBT2_PLP_ID</constant></title>

			<para>DVB-T2 supports Physical Layer Pipes (PLP) to allow transmission of
				many data types via a single multiplex. The API will soon support this
				at which point this section will be expanded.</para>
		</section>
	</section>
</section>
</section>