fe_property_parameters.rst (21973B)
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.