xref: /linux/Documentation/userspace-api/media/dvb/fe_property_parameters.rst (revision 4a95857a875e887cc958c92fe9d2cde6184d2ec0)
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2
3.. _fe_property_parameters:
4
5******************************
6Digital TV property parameters
7******************************
8
9There are several different Digital TV parameters that can be used by
10:ref:`FE_SET_PROPERTY and FE_GET_PROPERTY ioctls<FE_GET_PROPERTY>`.
11This section describes each of them. Please notice, however, that only
12a subset of them are needed to setup a frontend.
13
14
15.. _DTV-UNDEFINED:
16
17DTV_UNDEFINED
18=============
19
20Used internally. A GET/SET operation for it won't change or return
21anything.
22
23
24.. _DTV-TUNE:
25
26DTV_TUNE
27========
28
29Interpret the cache of data, build either a traditional frontend
30tunerequest so we can pass validation in the ``FE_SET_FRONTEND`` ioctl.
31
32
33.. _DTV-CLEAR:
34
35DTV_CLEAR
36=========
37
38Reset a cache of data specific to the frontend here. This does not
39effect hardware.
40
41
42.. _DTV-FREQUENCY:
43
44DTV_FREQUENCY
45=============
46
47Frequency of the digital TV transponder/channel.
48
49.. note::
50
51  #. For satellite delivery systems, the frequency is in kHz.
52
53  #. For cable and terrestrial delivery systems, the frequency is in
54     Hz.
55
56  #. On most delivery systems, the frequency is the center frequency
57     of the transponder/channel. The exception is for ISDB-T, where
58     the main carrier has a 1/7 offset from the center.
59
60  #. For ISDB-T, the channels are usually transmitted with an offset of
61     about 143kHz. E.g. a valid frequency could be 474,143 kHz. The
62     stepping is  bound to the bandwidth of the channel which is
63     typically 6MHz.
64
65  #. In ISDB-Tsb, the channel consists of only one or three segments the
66     frequency step is 429kHz, 3*429 respectively.
67
68
69.. _DTV-MODULATION:
70
71DTV_MODULATION
72==============
73
74Specifies the frontend modulation type for delivery systems that
75supports more multiple modulations.
76
77The modulation can be one of the types defined by enum :c:type:`fe_modulation`.
78
79Most of the digital TV standards offers more than one possible
80modulation type.
81
82The table below presents a summary of the types of modulation types
83supported by each delivery system, as currently defined by specs.
84
85======================= =======================================================
86Standard		Modulation types
87======================= =======================================================
88ATSC (version 1)	8-VSB and 16-VSB.
89DMTB			4-QAM, 16-QAM, 32-QAM, 64-QAM and 4-QAM-NR.
90DVB-C Annex A/C		16-QAM, 32-QAM, 64-QAM and 256-QAM.
91DVB-C Annex B		64-QAM.
92DVB-T			QPSK, 16-QAM and 64-QAM.
93DVB-T2			QPSK, 16-QAM, 64-QAM and 256-QAM.
94DVB-S			No need to set. It supports only QPSK.
95DVB-S2			QPSK, 8-PSK, 16-APSK and 32-APSK.
96ISDB-T			QPSK, DQPSK, 16-QAM and 64-QAM.
97ISDB-S			8-PSK, QPSK and BPSK.
98======================= =======================================================
99
100.. note::
101
102   Please notice that some of the above modulation types may not be
103   defined currently at the Kernel. The reason is simple: no driver
104   needed such definition yet.
105
106
107.. _DTV-BANDWIDTH-HZ:
108
109DTV_BANDWIDTH_HZ
110================
111
112Bandwidth for the channel, in HZ.
113
114Should be set only for terrestrial delivery systems.
115
116Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``,
117``8000000``, ``10000000``.
118
119======================= =======================================================
120Terrestrial Standard	Possible values for bandwidth
121======================= =======================================================
122ATSC (version 1)	No need to set. It is always 6MHz.
123DMTB			No need to set. It is always 8MHz.
124DVB-T			6MHz, 7MHz and 8MHz.
125DVB-T2			1.172 MHz, 5MHz, 6MHz, 7MHz, 8MHz and 10MHz
126ISDB-T			5MHz, 6MHz, 7MHz and 8MHz, although most places
127			use 6MHz.
128======================= =======================================================
129
130
131.. note::
132
133
134  #. For ISDB-Tsb, the bandwidth can vary depending on the number of
135     connected segments.
136
137     It can be easily derived from other parameters
138     (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT).
139
140  #. On Satellite and Cable delivery systems, the bandwidth depends on
141     the symbol rate. So, the Kernel will silently ignore any setting
142     :ref:`DTV-BANDWIDTH-HZ`. I will however fill it back with a
143     bandwidth estimation.
144
145     Such bandwidth estimation takes into account the symbol rate set with
146     :ref:`DTV-SYMBOL-RATE`, and the rolloff factor, with is fixed for
147     DVB-C and DVB-S.
148
149     For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`.
150
151
152.. _DTV-INVERSION:
153
154DTV_INVERSION
155=============
156
157Specifies if the frontend should do spectral inversion or not.
158
159The acceptable values are defined by :c:type:`fe_spectral_inversion`.
160
161
162.. _DTV-DISEQC-MASTER:
163
164DTV_DISEQC_MASTER
165=================
166
167Currently not implemented.
168
169
170.. _DTV-SYMBOL-RATE:
171
172DTV_SYMBOL_RATE
173===============
174
175Used on cable and satellite delivery systems.
176
177Digital TV symbol rate, in bauds (symbols/second).
178
179
180.. _DTV-INNER-FEC:
181
182DTV_INNER_FEC
183=============
184
185Used on cable and satellite delivery systems.
186
187The acceptable values are defined by :c:type:`fe_code_rate`.
188
189
190.. _DTV-VOLTAGE:
191
192DTV_VOLTAGE
193===========
194
195Used on satellite delivery systems.
196
197The voltage is usually used with non-DiSEqC capable LNBs to switch the
198polarzation (horizontal/vertical). When using DiSEqC epuipment this
199voltage has to be switched consistently to the DiSEqC commands as
200described in the DiSEqC spec.
201
202The acceptable values are defined by :c:type:`fe_sec_voltage`.
203
204
205.. _DTV-TONE:
206
207DTV_TONE
208========
209
210Currently not used.
211
212
213.. _DTV-PILOT:
214
215DTV_PILOT
216=========
217
218Used on DVB-S2.
219
220Sets DVB-S2 pilot.
221
222The acceptable values are defined by :c:type:`fe_pilot`.
223
224
225.. _DTV-ROLLOFF:
226
227DTV_ROLLOFF
228===========
229
230Used on DVB-S2.
231
232Sets DVB-S2 rolloff.
233
234The acceptable values are defined by :c:type:`fe_rolloff`.
235
236
237.. _DTV-DISEQC-SLAVE-REPLY:
238
239DTV_DISEQC_SLAVE_REPLY
240======================
241
242Currently not implemented.
243
244
245.. _DTV-FE-CAPABILITY-COUNT:
246
247DTV_FE_CAPABILITY_COUNT
248=======================
249
250Currently not implemented.
251
252
253.. _DTV-FE-CAPABILITY:
254
255DTV_FE_CAPABILITY
256=================
257
258Currently not implemented.
259
260
261.. _DTV-DELIVERY-SYSTEM:
262
263DTV_DELIVERY_SYSTEM
264===================
265
266Specifies the type of the delivery system.
267
268The acceptable values are defined by :c:type:`fe_delivery_system`.
269
270
271.. _DTV-ISDBT-PARTIAL-RECEPTION:
272
273DTV_ISDBT_PARTIAL_RECEPTION
274===========================
275
276Used only on ISDB.
277
278If ``DTV_ISDBT_SOUND_BROADCASTING`` is '0' this bit-field represents
279whether the channel is in partial reception mode or not.
280
281If '1' ``DTV_ISDBT_LAYERA_*`` values are assigned to the center segment
282and ``DTV_ISDBT_LAYERA_SEGMENT_COUNT`` has to be '1'.
283
284If in addition ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'
285``DTV_ISDBT_PARTIAL_RECEPTION`` represents whether this ISDB-Tsb channel
286is consisting of one segment and layer or three segments and two layers.
287
288Possible values: 0, 1, -1 (AUTO)
289
290
291.. _DTV-ISDBT-SOUND-BROADCASTING:
292
293DTV_ISDBT_SOUND_BROADCASTING
294============================
295
296Used only on ISDB.
297
298This field represents whether the other DTV_ISDBT_*-parameters are
299referring to an ISDB-T and an ISDB-Tsb channel. (See also
300``DTV_ISDBT_PARTIAL_RECEPTION``).
301
302Possible values: 0, 1, -1 (AUTO)
303
304
305.. _DTV-ISDBT-SB-SUBCHANNEL-ID:
306
307DTV_ISDBT_SB_SUBCHANNEL_ID
308==========================
309
310Used only on ISDB.
311
312This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'.
313
314(Note of the author: This might not be the correct description of the
315``SUBCHANNEL-ID`` in all details, but it is my understanding of the
316technical background needed to program a device)
317
318An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
319set of connected ISDB-Tsb channels. In this set of channels every
320channel can be received independently. The number of connected ISDB-Tsb
321segment can vary, e.g. depending on the frequency spectrum bandwidth
322available.
323
324Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
325broadcaster has several possibilities to put those channels in the air:
326Assuming a normal 13-segment ISDB-T spectrum he can align the 8 segments
327from position 1-8 to 5-13 or anything in between.
328
329The underlying layer of segments are subchannels: each segment is
330consisting of several subchannels with a predefined IDs. A sub-channel
331is used to help the demodulator to synchronize on the channel.
332
333An ISDB-T channel is always centered over all sub-channels. As for the
334example above, in ISDB-Tsb it is no longer as simple as that.
335
336``The DTV_ISDBT_SB_SUBCHANNEL_ID`` parameter is used to give the
337sub-channel ID of the segment to be demodulated.
338
339Possible values: 0 .. 41, -1 (AUTO)
340
341
342.. _DTV-ISDBT-SB-SEGMENT-IDX:
343
344DTV_ISDBT_SB_SEGMENT_IDX
345========================
346
347Used only on ISDB.
348
349This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'.
350
351``DTV_ISDBT_SB_SEGMENT_IDX`` gives the index of the segment to be
352demodulated for an ISDB-Tsb channel where several of them are
353transmitted in the connected manner.
354
355Possible values: 0 .. ``DTV_ISDBT_SB_SEGMENT_COUNT`` - 1
356
357Note: This value cannot be determined by an automatic channel search.
358
359
360.. _DTV-ISDBT-SB-SEGMENT-COUNT:
361
362DTV_ISDBT_SB_SEGMENT_COUNT
363==========================
364
365Used only on ISDB.
366
367This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'.
368
369``DTV_ISDBT_SB_SEGMENT_COUNT`` gives the total count of connected
370ISDB-Tsb channels.
371
372Possible values: 1 .. 13
373
374Note: This value cannot be determined by an automatic channel search.
375
376
377.. _isdb-hierq-layers:
378
379DTV-ISDBT-LAYER[A-C] parameters
380===============================
381
382Used only on ISDB.
383
384ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
385ISDB-T hierarchical layers can be decoded simultaneously. For that
386reason a ISDB-T demodulator has 3 Viterbi and 3 Reed-Solomon decoders.
387
388ISDB-T has 3 hierarchical layers which each can use a part of the
389available segments. The total number of segments over all layers has to
39013 in ISDB-T.
391
392There are 3 parameter sets, for Layers A, B and C.
393
394
395.. _DTV-ISDBT-LAYER-ENABLED:
396
397DTV_ISDBT_LAYER_ENABLED
398-----------------------
399
400Used only on ISDB.
401
402Hierarchical reception in ISDB-T is achieved by enabling or disabling
403layers in the decoding process. Setting all bits of
404``DTV_ISDBT_LAYER_ENABLED`` to '1' forces all layers (if applicable) to
405be demodulated. This is the default.
406
407If the channel is in the partial reception mode
408(``DTV_ISDBT_PARTIAL_RECEPTION`` = 1) the central segment can be decoded
409independently of the other 12 segments. In that mode layer A has to have
410a ``SEGMENT_COUNT`` of 1.
411
412In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb according
413to ``DTV_ISDBT_PARTIAL_RECEPTION``. ``SEGMENT_COUNT`` must be filled
414accordingly.
415
416Only the values of the first 3 bits are used. Other bits will be silently ignored:
417
418``DTV_ISDBT_LAYER_ENABLED`` bit 0: layer A enabled
419
420``DTV_ISDBT_LAYER_ENABLED`` bit 1: layer B enabled
421
422``DTV_ISDBT_LAYER_ENABLED`` bit 2: layer C enabled
423
424``DTV_ISDBT_LAYER_ENABLED`` bits 3-31: unused
425
426
427.. _DTV-ISDBT-LAYER-FEC:
428
429DTV_ISDBT_LAYER[A-C]_FEC
430------------------------
431
432Used only on ISDB.
433
434The Forward Error Correction mechanism used by a given ISDB Layer, as
435defined by :c:type:`fe_code_rate`.
436
437
438Possible values are: ``FEC_AUTO``, ``FEC_1_2``, ``FEC_2_3``, ``FEC_3_4``,
439``FEC_5_6``, ``FEC_7_8``
440
441
442.. _DTV-ISDBT-LAYER-MODULATION:
443
444DTV_ISDBT_LAYER[A-C]_MODULATION
445-------------------------------
446
447Used only on ISDB.
448
449The modulation used by a given ISDB Layer, as defined by
450:c:type:`fe_modulation`.
451
452Possible values are: ``QAM_AUTO``, ``QPSK``, ``QAM_16``, ``QAM_64``, ``DQPSK``
453
454.. note::
455
456   #. If layer C is ``DQPSK``, then layer B has to be ``DQPSK``.
457
458   #. If layer B is ``DQPSK`` and ``DTV_ISDBT_PARTIAL_RECEPTION``\ = 0,
459      then layer has to be ``DQPSK``.
460
461
462.. _DTV-ISDBT-LAYER-SEGMENT-COUNT:
463
464DTV_ISDBT_LAYER[A-C]_SEGMENT_COUNT
465----------------------------------
466
467Used only on ISDB.
468
469Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)
470
471Note: Truth table for ``DTV_ISDBT_SOUND_BROADCASTING`` and
472``DTV_ISDBT_PARTIAL_RECEPTION`` and ``LAYER[A-C]_SEGMENT_COUNT``
473
474.. _isdbt-layer_seg-cnt-table:
475
476.. flat-table:: Truth table for ISDB-T Sound Broadcasting
477    :header-rows:  1
478    :stub-columns: 0
479
480
481    -  .. row 1
482
483       -  Partial Reception
484
485       -  Sound Broadcasting
486
487       -  Layer A width
488
489       -  Layer B width
490
491       -  Layer C width
492
493       -  total width
494
495    -  .. row 2
496
497       -  0
498
499       -  0
500
501       -  1 .. 13
502
503       -  1 .. 13
504
505       -  1 .. 13
506
507       -  13
508
509    -  .. row 3
510
511       -  1
512
513       -  0
514
515       -  1
516
517       -  1 .. 13
518
519       -  1 .. 13
520
521       -  13
522
523    -  .. row 4
524
525       -  0
526
527       -  1
528
529       -  1
530
531       -  0
532
533       -  0
534
535       -  1
536
537    -  .. row 5
538
539       -  1
540
541       -  1
542
543       -  1
544
545       -  2
546
547       -  0
548
549       -  13
550
551
552
553.. _DTV-ISDBT-LAYER-TIME-INTERLEAVING:
554
555DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING
556--------------------------------------
557
558Used only on ISDB.
559
560Valid values: 0, 1, 2, 4, -1 (AUTO)
561
562when DTV_ISDBT_SOUND_BROADCASTING is active, value 8 is also valid.
563
564Note: The real time interleaving length depends on the mode (fft-size).
565The values here are referring to what can be found in the
566TMCC-structure, as shown in the table below.
567
568
569.. c:type:: isdbt_layer_interleaving_table
570
571.. flat-table:: ISDB-T time interleaving modes
572    :header-rows:  1
573    :stub-columns: 0
574
575
576    -  .. row 1
577
578       -  ``DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING``
579
580       -  Mode 1 (2K FFT)
581
582       -  Mode 2 (4K FFT)
583
584       -  Mode 3 (8K FFT)
585
586    -  .. row 2
587
588       -  0
589
590       -  0
591
592       -  0
593
594       -  0
595
596    -  .. row 3
597
598       -  1
599
600       -  4
601
602       -  2
603
604       -  1
605
606    -  .. row 4
607
608       -  2
609
610       -  8
611
612       -  4
613
614       -  2
615
616    -  .. row 5
617
618       -  4
619
620       -  16
621
622       -  8
623
624       -  4
625
626
627
628.. _DTV-ATSCMH-FIC-VER:
629
630DTV_ATSCMH_FIC_VER
631------------------
632
633Used only on ATSC-MH.
634
635Version number of the FIC (Fast Information Channel) signaling data.
636
637FIC is used for relaying information to allow rapid service acquisition
638by the receiver.
639
640Possible values: 0, 1, 2, 3, ..., 30, 31
641
642
643.. _DTV-ATSCMH-PARADE-ID:
644
645DTV_ATSCMH_PARADE_ID
646--------------------
647
648Used only on ATSC-MH.
649
650Parade identification number
651
652A parade is a collection of up to eight MH groups, conveying one or two
653ensembles.
654
655Possible values: 0, 1, 2, 3, ..., 126, 127
656
657
658.. _DTV-ATSCMH-NOG:
659
660DTV_ATSCMH_NOG
661--------------
662
663Used only on ATSC-MH.
664
665Number of MH groups per MH subframe for a designated parade.
666
667Possible values: 1, 2, 3, 4, 5, 6, 7, 8
668
669
670.. _DTV-ATSCMH-TNOG:
671
672DTV_ATSCMH_TNOG
673---------------
674
675Used only on ATSC-MH.
676
677Total number of MH groups including all MH groups belonging to all MH
678parades in one MH subframe.
679
680Possible values: 0, 1, 2, 3, ..., 30, 31
681
682
683.. _DTV-ATSCMH-SGN:
684
685DTV_ATSCMH_SGN
686--------------
687
688Used only on ATSC-MH.
689
690Start group number.
691
692Possible values: 0, 1, 2, 3, ..., 14, 15
693
694
695.. _DTV-ATSCMH-PRC:
696
697DTV_ATSCMH_PRC
698--------------
699
700Used only on ATSC-MH.
701
702Parade repetition cycle.
703
704Possible values: 1, 2, 3, 4, 5, 6, 7, 8
705
706
707.. _DTV-ATSCMH-RS-FRAME-MODE:
708
709DTV_ATSCMH_RS_FRAME_MODE
710------------------------
711
712Used only on ATSC-MH.
713
714Reed Solomon (RS) frame mode.
715
716The acceptable values are defined by :c:type:`atscmh_rs_frame_mode`.
717
718
719.. _DTV-ATSCMH-RS-FRAME-ENSEMBLE:
720
721DTV_ATSCMH_RS_FRAME_ENSEMBLE
722----------------------------
723
724Used only on ATSC-MH.
725
726Reed Solomon(RS) frame ensemble.
727
728The acceptable values are defined by :c:type:`atscmh_rs_frame_ensemble`.
729
730
731.. _DTV-ATSCMH-RS-CODE-MODE-PRI:
732
733DTV_ATSCMH_RS_CODE_MODE_PRI
734---------------------------
735
736Used only on ATSC-MH.
737
738Reed Solomon (RS) code mode (primary).
739
740The acceptable values are defined by :c:type:`atscmh_rs_code_mode`.
741
742
743.. _DTV-ATSCMH-RS-CODE-MODE-SEC:
744
745DTV_ATSCMH_RS_CODE_MODE_SEC
746---------------------------
747
748Used only on ATSC-MH.
749
750Reed Solomon (RS) code mode (secondary).
751
752The acceptable values are defined by :c:type:`atscmh_rs_code_mode`.
753
754
755.. _DTV-ATSCMH-SCCC-BLOCK-MODE:
756
757DTV_ATSCMH_SCCC_BLOCK_MODE
758--------------------------
759
760Used only on ATSC-MH.
761
762Series Concatenated Convolutional Code Block Mode.
763
764The acceptable values are defined by :c:type:`atscmh_sccc_block_mode`.
765
766
767.. _DTV-ATSCMH-SCCC-CODE-MODE-A:
768
769DTV_ATSCMH_SCCC_CODE_MODE_A
770---------------------------
771
772Used only on ATSC-MH.
773
774Series Concatenated Convolutional Code Rate.
775
776The acceptable values are defined by :c:type:`atscmh_sccc_code_mode`.
777
778.. _DTV-ATSCMH-SCCC-CODE-MODE-B:
779
780DTV_ATSCMH_SCCC_CODE_MODE_B
781---------------------------
782
783Used only on ATSC-MH.
784
785Series Concatenated Convolutional Code Rate.
786
787Possible values are the same as documented on enum
788:c:type:`atscmh_sccc_code_mode`.
789
790
791.. _DTV-ATSCMH-SCCC-CODE-MODE-C:
792
793DTV_ATSCMH_SCCC_CODE_MODE_C
794---------------------------
795
796Used only on ATSC-MH.
797
798Series Concatenated Convolutional Code Rate.
799
800Possible values are the same as documented on enum
801:c:type:`atscmh_sccc_code_mode`.
802
803
804.. _DTV-ATSCMH-SCCC-CODE-MODE-D:
805
806DTV_ATSCMH_SCCC_CODE_MODE_D
807---------------------------
808
809Used only on ATSC-MH.
810
811Series Concatenated Convolutional Code Rate.
812
813Possible values are the same as documented on enum
814:c:type:`atscmh_sccc_code_mode`.
815
816
817.. _DTV-API-VERSION:
818
819DTV_API_VERSION
820===============
821
822Returns the major/minor version of the Digital TV API
823
824
825.. _DTV-CODE-RATE-HP:
826
827DTV_CODE_RATE_HP
828================
829
830Used on terrestrial transmissions.
831
832The acceptable values are defined by :c:type:`fe_transmit_mode`.
833
834
835.. _DTV-CODE-RATE-LP:
836
837DTV_CODE_RATE_LP
838================
839
840Used on terrestrial transmissions.
841
842The acceptable values are defined by :c:type:`fe_transmit_mode`.
843
844
845.. _DTV-GUARD-INTERVAL:
846
847DTV_GUARD_INTERVAL
848==================
849
850The acceptable values are defined by :c:type:`fe_guard_interval`.
851
852.. note::
853
854   #. If ``DTV_GUARD_INTERVAL`` is set the ``GUARD_INTERVAL_AUTO`` the
855      hardware will try to find the correct guard interval (if capable) and
856      will use TMCC to fill in the missing parameters.
857   #. Intervals ``GUARD_INTERVAL_1_128``, ``GUARD_INTERVAL_19_128``
858      and ``GUARD_INTERVAL_19_256`` are used only for DVB-T2 at
859      present.
860   #. Intervals ``GUARD_INTERVAL_PN420``, ``GUARD_INTERVAL_PN595`` and
861      ``GUARD_INTERVAL_PN945`` are used only for DMTB at the present.
862      On such standard, only those intervals and ``GUARD_INTERVAL_AUTO``
863      are valid.
864
865.. _DTV-TRANSMISSION-MODE:
866
867DTV_TRANSMISSION_MODE
868=====================
869
870
871Used only on OFTM-based standards, e. g. DVB-T/T2, ISDB-T, DTMB.
872
873Specifies the FFT size (with corresponds to the approximate number of
874carriers) used by the standard.
875
876The acceptable values are defined by :c:type:`fe_transmit_mode`.
877
878.. note::
879
880   #. ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
881      **mode** on such standard, and are numbered from 1 to 3:
882
883      ====	========	========================
884      Mode	FFT size	Transmission mode
885      ====	========	========================
886      1		2K		``TRANSMISSION_MODE_2K``
887      2		4K		``TRANSMISSION_MODE_4K``
888      3		8K		``TRANSMISSION_MODE_8K``
889      ====	========	========================
890
891   #. If ``DTV_TRANSMISSION_MODE`` is set the ``TRANSMISSION_MODE_AUTO``
892      the hardware will try to find the correct FFT-size (if capable) and
893      will use TMCC to fill in the missing parameters.
894
895   #. DVB-T specifies 2K and 8K as valid sizes.
896
897   #. DVB-T2 specifies 1K, 2K, 4K, 8K, 16K and 32K.
898
899   #. DTMB specifies C1 and C3780.
900
901
902.. _DTV-HIERARCHY:
903
904DTV_HIERARCHY
905=============
906
907Used only on DVB-T and DVB-T2.
908
909Frontend hierarchy.
910
911The acceptable values are defined by :c:type:`fe_hierarchy`.
912
913
914.. _DTV-STREAM-ID:
915
916DTV_STREAM_ID
917=============
918
919Used on DVB-S2, DVB-T2 and ISDB-S.
920
921DVB-S2, DVB-T2 and ISDB-S support the transmission of several streams on
922a single transport stream. This property enables the digital TV driver to
923handle substream filtering, when supported by the hardware. By default,
924substream filtering is disabled.
925
926For DVB-S2 and DVB-T2, the valid substream id range is from 0 to 255.
927
928For ISDB, the valid substream id range is from 1 to 65535.
929
930To disable it, you should use the special macro NO_STREAM_ID_FILTER.
931
932Note: any value outside the id range also disables filtering.
933
934
935.. _DTV-DVBT2-PLP-ID-LEGACY:
936
937DTV_DVBT2_PLP_ID_LEGACY
938=======================
939
940Obsolete, replaced with DTV_STREAM_ID.
941
942
943.. _DTV-ENUM-DELSYS:
944
945DTV_ENUM_DELSYS
946===============
947
948A Multi standard frontend needs to advertise the delivery systems
949provided. Applications need to enumerate the provided delivery systems,
950before using any other operation with the frontend. Prior to it's
951introduction, FE_GET_INFO was used to determine a frontend type. A
952frontend which provides more than a single delivery system,
953FE_GET_INFO doesn't help much. Applications which intends to use a
954multistandard frontend must enumerate the delivery systems associated
955with it, rather than trying to use FE_GET_INFO. In the case of a
956legacy frontend, the result is just the same as with FE_GET_INFO, but
957in a more structured format
958
959The acceptable values are defined by :c:type:`fe_delivery_system`.
960
961
962.. _DTV-INTERLEAVING:
963
964DTV_INTERLEAVING
965================
966
967Time interleaving to be used.
968
969The acceptable values are defined by :c:type:`fe_interleaving`.
970
971
972.. _DTV-LNA:
973
974DTV_LNA
975=======
976
977Low-noise amplifier.
978
979Hardware might offer controllable LNA which can be set manually using
980that parameter. Usually LNA could be found only from terrestrial devices
981if at all.
982
983Possible values: 0, 1, LNA_AUTO
984
9850, LNA off
986
9871, LNA on
988
989use the special macro LNA_AUTO to set LNA auto
990
991
992.. _DTV-SCRAMBLING-SEQUENCE-INDEX:
993
994DTV_SCRAMBLING_SEQUENCE_INDEX
995=============================
996
997Used on DVB-S2.
998
999This 18 bit field, when present, carries the index of the DVB-S2 physical
1000layer scrambling sequence as defined in clause 5.5.4 of EN 302 307.
1001There is no explicit signalling method to convey scrambling sequence index
1002to the receiver. If S2 satellite delivery system descriptor is available
1003it can be used to read the scrambling sequence index (EN 300 468 table 41).
1004
1005By default, gold scrambling sequence index 0 is used.
1006
1007The valid scrambling sequence index range is from 0 to 262142.
1008