| <section id="FE_GET_PROPERTY"> |
| <title>FE_GET_PROPERTY/FE_SET_PROPERTY</title> |
| |
| <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-parms"> |
| <title>Parameters that are common with DVB-T and ATSC</title> |
| |
| <section id="isdbt-freq"> |
| <title><constant>DTV_FREQUENCY</constant></title> |
| |
| <para>Central frequency of the channel.</para> |
| |
| <para>For ISDB-T the channels are usally 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>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="isdbt-bw"> |
| <title><constant>DTV_BANDWIDTH_HZ</constant> (optional)</title> |
| |
| <para>Possible values:</para> |
| |
| <para>For ISDB-T it should be always 6000000Hz (6MHz)</para> |
| <para>For ISDB-Tsb it can vary depending on the number of connected segments</para> |
| |
| <para>Note: Hardware specific values might be given here, but standard |
| applications should not bother to set a value to this field as |
| standard demods are ignoring it anyway.</para> |
| |
| <para>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> |
| </section> |
| |
| <section id="isdbt-delivery-sys"> |
| <title><constant>DTV_DELIVERY_SYSTEM</constant></title> |
| |
| <para>Possible values: <constant>SYS_ISDBT</constant></para> |
| </section> |
| |
| <section id="isdbt-tx-mode"> |
| <title><constant>DTV_TRANSMISSION_MODE</constant></title> |
| |
| <para>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>Possible values: <constant>TRANSMISSION_MODE_2K</constant>, <constant>TRANSMISSION_MODE_8K</constant>, |
| <constant>TRANSMISSION_MODE_AUTO</constant>, <constant>TRANSMISSION_MODE_4K</constant></para> |
| |
| <para>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><constant>TRANSMISSION_MODE_4K</constant> is added at the same time as the other new parameters.</para> |
| </section> |
| |
| <section id="isdbt-guard-interval"> |
| <title><constant>DTV_GUARD_INTERVAL</constant></title> |
| |
| <para>Possible values: <constant>GUARD_INTERVAL_1_32</constant>, <constant>GUARD_INTERVAL_1_16</constant>, <constant>GUARD_INTERVAL_1_8</constant>, |
| <constant>GUARD_INTERVAL_1_4</constant>, <constant>GUARD_INTERVAL_AUTO</constant></para> |
| |
| <para>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> |
| </section> |
| </section> |
| <section id="isdbt-new-parms"> |
| <title>ISDB-T only parameters</title> |
| |
| <section id="isdbt-part-rec"> |
| <title><constant>DTV_ISDBT_PARTIAL_RECEPTION</constant></title> |
| |
| <para><constant>If 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="isdbt-sound-bcast"> |
| <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="isdbt-sb-ch-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="isdbt-sb-seg-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="isdbt-sb-seg-cnt"> |
| <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="isdbt-layer-ena"> |
| <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="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="isdbt-layer-mod"> |
| <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="isdbt-layer-seg-cnt"> |
| <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="isdbt_layer_t_interl"> |
| <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> |
| </section> |