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1 | <section id="FE_GET_PROPERTY"> |
2 | <title>FE_GET_PROPERTY/FE_SET_PROPERTY</title> | |
3 | ||
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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 | ||
25985edc | 43 | <para>For ISDB-T the channels are usually transmitted with an offset of 143kHz. E.g. a |
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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> | |
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102 | <section id="isdbt-new-parms"> |
103 | <title>ISDB-T only parameters</title> | |
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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 | ||
c18038d2 | 128 | <para>Possible values: 0, 1, -1 (AUTO)</para> |
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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> | |
131db3a1 | 318 | </section> |