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diff --git a/Documentation/DocBook/dvb/isdbt.xml b/Documentation/DocBook/dvb/isdbt.xml new file mode 100644 index 0000000..39e4696 --- /dev/null +++ b/Documentation/DocBook/dvb/isdbt.xml @@ -0,0 +1,313 @@ +<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">ISDB-T only parameters + + <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> + + Possible values: 0, 1, -1 (AUTO) + </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> |
