<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 ⋆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 ⋆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>
