1<section id="FE_GET_PROPERTY"> 2<title>FE_GET_PROPERTY/FE_SET_PROPERTY</title> 3 4<section id="isdbt"> 5 <title>ISDB-T frontend</title> 6 <para>This section describes shortly what are the possible parameters in the Linux 7 DVB-API called "S2API" and now DVB API 5 in order to tune an ISDB-T/ISDB-Tsb 8 demodulator:</para> 9 10 <para>This ISDB-T/ISDB-Tsb API extension should reflect all information 11 needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible 12 that some very sophisticated devices won't need certain parameters to 13 tune.</para> 14 15 <para>The information given here should help application writers to know how 16 to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.</para> 17 18 <para>The details given here about ISDB-T and ISDB-Tsb are just enough to 19 basically show the dependencies between the needed parameter values, 20 but surely some information is left out. For more detailed information 21 see the following documents:</para> 22 23 <para>ARIB STD-B31 - "Transmission System for Digital Terrestrial 24 Television Broadcasting" and</para> 25 <para>ARIB TR-B14 - "Operational Guidelines for Digital Terrestrial 26 Television Broadcasting".</para> 27 28 <para>In order to read this document one has to have some knowledge the 29 channel structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to 30 the reader that an ISDB-T channel consists of 13 segments, that it can 31 have up to 3 layer sharing those segments, and things like that.</para> 32 33 <para>Parameters used by ISDB-T and ISDB-Tsb.</para> 34 35 <section id="isdbt-parms"> 36 <title>Parameters that are common with DVB-T and ATSC</title> 37 38 <section id="isdbt-freq"> 39 <title><constant>DTV_FREQUENCY</constant></title> 40 41 <para>Central frequency of the channel.</para> 42 43 <para>For ISDB-T the channels are usally transmitted with an offset of 143kHz. E.g. a 44 valid frequncy could be 474143 kHz. The stepping is bound to the bandwidth of 45 the channel which is 6MHz.</para> 46 47 <para>As in ISDB-Tsb the channel consists of only one or three segments the 48 frequency step is 429kHz, 3*429 respectively. As for ISDB-T the 49 central frequency of the channel is expected.</para> 50 </section> 51 52 <section id="isdbt-bw"> 53 <title><constant>DTV_BANDWIDTH_HZ</constant> (optional)</title> 54 55 <para>Possible values:</para> 56 57 <para>For ISDB-T it should be always 6000000Hz (6MHz)</para> 58 <para>For ISDB-Tsb it can vary depending on the number of connected segments</para> 59 60 <para>Note: Hardware specific values might be given here, but standard 61 applications should not bother to set a value to this field as 62 standard demods are ignoring it anyway.</para> 63 64 <para>Bandwidth in ISDB-T is fixed (6MHz) or can be easily derived from 65 other parameters (DTV_ISDBT_SB_SEGMENT_IDX, 66 DTV_ISDBT_SB_SEGMENT_COUNT).</para> 67 </section> 68 69 <section id="isdbt-delivery-sys"> 70 <title><constant>DTV_DELIVERY_SYSTEM</constant></title> 71 72 <para>Possible values: <constant>SYS_ISDBT</constant></para> 73 </section> 74 75 <section id="isdbt-tx-mode"> 76 <title><constant>DTV_TRANSMISSION_MODE</constant></title> 77 78 <para>ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called 79 'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K</para> 80 81 <para>Possible values: <constant>TRANSMISSION_MODE_2K</constant>, <constant>TRANSMISSION_MODE_8K</constant>, 82 <constant>TRANSMISSION_MODE_AUTO</constant>, <constant>TRANSMISSION_MODE_4K</constant></para> 83 84 <para>If <constant>DTV_TRANSMISSION_MODE</constant> is set the <constant>TRANSMISSION_MODE_AUTO</constant> the 85 hardware will try to find the correct FFT-size (if capable) and will 86 use TMCC to fill in the missing parameters.</para> 87 88 <para><constant>TRANSMISSION_MODE_4K</constant> is added at the same time as the other new parameters.</para> 89 </section> 90 91 <section id="isdbt-guard-interval"> 92 <title><constant>DTV_GUARD_INTERVAL</constant></title> 93 94 <para>Possible values: <constant>GUARD_INTERVAL_1_32</constant>, <constant>GUARD_INTERVAL_1_16</constant>, <constant>GUARD_INTERVAL_1_8</constant>, 95 <constant>GUARD_INTERVAL_1_4</constant>, <constant>GUARD_INTERVAL_AUTO</constant></para> 96 97 <para>If <constant>DTV_GUARD_INTERVAL</constant> is set the <constant>GUARD_INTERVAL_AUTO</constant> the hardware will 98 try to find the correct guard interval (if capable) and will use TMCC to fill 99 in the missing parameters.</para> 100 </section> 101 </section> 102 <section id="isdbt-new-parms"> 103 <title>ISDB-T only parameters</title> 104 105 <section id="isdbt-part-rec"> 106 <title><constant>DTV_ISDBT_PARTIAL_RECEPTION</constant></title> 107 108 <para><constant>If DTV_ISDBT_SOUND_BROADCASTING</constant> is '0' this bit-field represents whether 109 the channel is in partial reception mode or not.</para> 110 111 <para>If '1' <constant>DTV_ISDBT_LAYERA_*</constant> values are assigned to the center segment and 112 <constant>DTV_ISDBT_LAYERA_SEGMENT_COUNT</constant> has to be '1'.</para> 113 114 <para>If in addition <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1' 115 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> represents whether this ISDB-Tsb channel 116 is consisting of one segment and layer or three segments and two layers.</para> 117 118 <para>Possible values: 0, 1, -1 (AUTO)</para> 119 </section> 120 121 <section id="isdbt-sound-bcast"> 122 <title><constant>DTV_ISDBT_SOUND_BROADCASTING</constant></title> 123 124 <para>This field represents whether the other DTV_ISDBT_*-parameters are 125 referring to an ISDB-T and an ISDB-Tsb channel. (See also 126 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>).</para> 127 128 <para>Possible values: 0, 1, -1 (AUTO)</para> 129 </section> 130 131 <section id="isdbt-sb-ch-id"> 132 <title><constant>DTV_ISDBT_SB_SUBCHANNEL_ID</constant></title> 133 134 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para> 135 136 <para>(Note of the author: This might not be the correct description of the 137 <constant>SUBCHANNEL-ID</constant> in all details, but it is my understanding of the technical 138 background needed to program a device)</para> 139 140 <para>An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a 141 set of connected ISDB-Tsb channels. In this set of channels every 142 channel can be received independently. The number of connected 143 ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum 144 bandwidth available.</para> 145 146 <para>Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The 147 broadcaster has several possibilities to put those channels in the 148 air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8 149 segments from position 1-8 to 5-13 or anything in between.</para> 150 151 <para>The underlying layer of segments are subchannels: each segment is 152 consisting of several subchannels with a predefined IDs. A sub-channel 153 is used to help the demodulator to synchronize on the channel.</para> 154 155 <para>An ISDB-T channel is always centered over all sub-channels. As for 156 the example above, in ISDB-Tsb it is no longer as simple as that.</para> 157 158 <para><constant>The DTV_ISDBT_SB_SUBCHANNEL_ID</constant> parameter is used to give the 159 sub-channel ID of the segment to be demodulated.</para> 160 161 <para>Possible values: 0 .. 41, -1 (AUTO)</para> 162 </section> 163 164 <section id="isdbt-sb-seg-idx"> 165 166 <title><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant></title> 167 168 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para> 169 170 <para><constant>DTV_ISDBT_SB_SEGMENT_IDX</constant> gives the index of the segment to be 171 demodulated for an ISDB-Tsb channel where several of them are 172 transmitted in the connected manner.</para> 173 174 <para>Possible values: 0 .. <constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> - 1</para> 175 176 <para>Note: This value cannot be determined by an automatic channel search.</para> 177 </section> 178 179 <section id="isdbt-sb-seg-cnt"> 180 <title><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant></title> 181 182 <para>This field only applies if <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> is '1'.</para> 183 184 <para><constant>DTV_ISDBT_SB_SEGMENT_COUNT</constant> gives the total count of connected ISDB-Tsb 185 channels.</para> 186 187 <para>Possible values: 1 .. 13</para> 188 189 <para>Note: This value cannot be determined by an automatic channel search.</para> 190 </section> 191 192 <section id="isdb-hierq-layers"> 193 <title>Hierarchical layers</title> 194 195 <para>ISDB-T channels can be coded hierarchically. As opposed to DVB-T in 196 ISDB-T hierarchical layers can be decoded simultaneously. For that 197 reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.</para> 198 199 <para>ISDB-T has 3 hierarchical layers which each can use a part of the 200 available segments. The total number of segments over all layers has 201 to 13 in ISDB-T.</para> 202 203 <section id="isdbt-layer-ena"> 204 <title><constant>DTV_ISDBT_LAYER_ENABLED</constant></title> 205 206 <para>Hierarchical reception in ISDB-T is achieved by enabling or disabling 207 layers in the decoding process. Setting all bits of 208 <constant>DTV_ISDBT_LAYER_ENABLED</constant> to '1' forces all layers (if applicable) to be 209 demodulated. This is the default.</para> 210 211 <para>If the channel is in the partial reception mode 212 (<constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> = 1) the central segment can be decoded 213 independently of the other 12 segments. In that mode layer A has to 214 have a <constant>SEGMENT_COUNT</constant> of 1.</para> 215 216 <para>In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb 217 according to <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>. <constant>SEGMENT_COUNT</constant> must be filled 218 accordingly.</para> 219 220 <para>Possible values: 0x1, 0x2, 0x4 (|-able)</para> 221 222 <para><constant>DTV_ISDBT_LAYER_ENABLED[0:0]</constant> - layer A</para> 223 <para><constant>DTV_ISDBT_LAYER_ENABLED[1:1]</constant> - layer B</para> 224 <para><constant>DTV_ISDBT_LAYER_ENABLED[2:2]</constant> - layer C</para> 225 <para><constant>DTV_ISDBT_LAYER_ENABLED[31:3]</constant> unused</para> 226 </section> 227 228 <section id="isdbt-layer-fec"> 229 <title><constant>DTV_ISDBT_LAYER*_FEC</constant></title> 230 231 <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> 232 </section> 233 234 <section id="isdbt-layer-mod"> 235 <title><constant>DTV_ISDBT_LAYER*_MODULATION</constant></title> 236 237 <para>Possible values: <constant>QAM_AUTO</constant>, QP<constant>SK, QAM_16</constant>, <constant>QAM_64</constant>, <constant>DQPSK</constant></para> 238 239 <para>Note: If layer C is <constant>DQPSK</constant> layer B has to be <constant>DQPSK</constant>. If layer B is <constant>DQPSK</constant> 240 and <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant>=0 layer has to be <constant>DQPSK</constant>.</para> 241 </section> 242 243 <section id="isdbt-layer-seg-cnt"> 244 <title><constant>DTV_ISDBT_LAYER*_SEGMENT_COUNT</constant></title> 245 246 <para>Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)</para> 247 248 <para>Note: Truth table for <constant>DTV_ISDBT_SOUND_BROADCASTING</constant> and 249 <constant>DTV_ISDBT_PARTIAL_RECEPTION</constant> and <constant>LAYER</constant>*_SEGMENT_COUNT</para> 250 251 <informaltable id="isdbt-layer_seg-cnt-table"> 252 <tgroup cols="6"> 253 254 <tbody> 255 <row> 256 <entry>PR</entry> 257 <entry>SB</entry> 258 <entry>Layer A width</entry> 259 <entry>Layer B width</entry> 260 <entry>Layer C width</entry> 261 <entry>total width</entry> 262 </row> 263 264 <row> 265 <entry>0</entry> 266 <entry>0</entry> 267 <entry>1 .. 13</entry> 268 <entry>1 .. 13</entry> 269 <entry>1 .. 13</entry> 270 <entry>13</entry> 271 </row> 272 273 <row> 274 <entry>1</entry> 275 <entry>0</entry> 276 <entry>1</entry> 277 <entry>1 .. 13</entry> 278 <entry>1 .. 13</entry> 279 <entry>13</entry> 280 </row> 281 282 <row> 283 <entry>0</entry> 284 <entry>1</entry> 285 <entry>1</entry> 286 <entry>0</entry> 287 <entry>0</entry> 288 <entry>1</entry> 289 </row> 290 291 <row> 292 <entry>1</entry> 293 <entry>1</entry> 294 <entry>1</entry> 295 <entry>2</entry> 296 <entry>0</entry> 297 <entry>13</entry> 298 </row> 299 </tbody> 300 301 </tgroup> 302 </informaltable> 303 304 </section> 305 306 <section id="isdbt_layer_t_interl"> 307 <title><constant>DTV_ISDBT_LAYER*_TIME_INTERLEAVING</constant></title> 308 309 <para>Possible values: 0, 1, 2, 3, -1 (AUTO)</para> 310 311 <para>Note: The real inter-leaver depth-names depend on the mode (fft-size); the values 312 here are referring to what can be found in the TMCC-structure - 313 independent of the mode.</para> 314 </section> 315 </section> 316 </section> 317</section> 318</section> 319