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 75support 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 offer 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-C2 QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM and 4096-QAM. 93DVB-T QPSK, 16-QAM and 64-QAM. 94DVB-T2 QPSK, 16-QAM, 64-QAM and 256-QAM. 95DVB-S No need to set. It supports only QPSK. 96DVB-S2 QPSK, 8-PSK, 16-APSK and 32-APSK. 97DVB-S2X 8-APSK-L, 16-APSK-L, 32-APSK-L, 64-APSK and 64-APSK-L. 98ISDB-T QPSK, DQPSK, 16-QAM and 64-QAM. 99ISDB-S 8-PSK, QPSK and BPSK. 100======================= ======================================================= 101 102.. note:: 103 104 As DVB-S2X specifies extensions to the DVB-S2 standard, the same 105 delivery system enum value is used (SYS_DVBS2). 106 107 Please notice that some of the above modulation types may not be 108 defined currently at the Kernel. The reason is simple: no driver 109 needed such definition yet. 110 111 112.. _DTV-BANDWIDTH-HZ: 113 114DTV_BANDWIDTH_HZ 115================ 116 117Bandwidth for the channel, in HZ. 118 119Should be set only for terrestrial delivery systems. 120 121Possible values: ``1712000``, ``5000000``, ``6000000``, ``7000000``, 122``8000000``, ``10000000``. 123 124======================= ======================================================= 125Terrestrial Standard Possible values for bandwidth 126======================= ======================================================= 127ATSC (version 1) No need to set. It is always 6MHz. 128DMTB No need to set. It is always 8MHz. 129DVB-T 6MHz, 7MHz and 8MHz. 130DVB-T2 1.172 MHz, 5MHz, 6MHz, 7MHz, 8MHz and 10MHz 131ISDB-T 5MHz, 6MHz, 7MHz and 8MHz, although most places 132 use 6MHz. 133======================= ======================================================= 134 135 136.. note:: 137 138 139 #. For ISDB-Tsb, the bandwidth can vary depending on the number of 140 connected segments. 141 142 It can be easily derived from other parameters 143 (DTV_ISDBT_SB_SEGMENT_IDX, DTV_ISDBT_SB_SEGMENT_COUNT). 144 145 #. On Satellite and Cable delivery systems, the bandwidth depends on 146 the symbol rate. The kernel will silently ignore any :ref:`DTV-BANDWIDTH-HZ` 147 setting and overwrites it with bandwidth estimation. 148 149 Such bandwidth estimation takes into account the symbol rate set with 150 :ref:`DTV-SYMBOL-RATE`, and the rolloff factor, with is fixed for 151 DVB-C and DVB-S. 152 153 For DVB-S2, the rolloff should also be set via :ref:`DTV-ROLLOFF`. 154 155 156.. _DTV-INVERSION: 157 158DTV_INVERSION 159============= 160 161Specifies if the frontend should do spectral inversion or not. 162 163The acceptable values are defined by :c:type:`fe_spectral_inversion`. 164 165 166.. _DTV-DISEQC-MASTER: 167 168DTV_DISEQC_MASTER 169================= 170 171Currently not implemented. 172 173 174.. _DTV-SYMBOL-RATE: 175 176DTV_SYMBOL_RATE 177=============== 178 179Used on cable and satellite delivery systems. 180 181Digital TV symbol rate, in bauds (symbols/second). 182 183 184.. _DTV-INNER-FEC: 185 186DTV_INNER_FEC 187============= 188 189Used on cable and satellite delivery systems. 190 191The acceptable values are defined by :c:type:`fe_code_rate`. 192 193 194.. _DTV-VOLTAGE: 195 196DTV_VOLTAGE 197=========== 198 199Used on satellite delivery systems. 200 201The voltage is usually used with non-DiSEqC capable LNBs to switch the 202polarization (horizontal/vertical). When using DiSEqC equipment this 203voltage has to be switched consistently to the DiSEqC commands as 204described in the DiSEqC spec. 205 206The acceptable values are defined by :c:type:`fe_sec_voltage`. 207 208 209.. _DTV-TONE: 210 211DTV_TONE 212======== 213 214Currently not used. 215 216 217.. _DTV-PILOT: 218 219DTV_PILOT 220========= 221 222Used on DVB-S2. 223 224Sets DVB-S2 pilot. 225 226The acceptable values are defined by :c:type:`fe_pilot`. 227 228 229.. _DTV-ROLLOFF: 230 231DTV_ROLLOFF 232=========== 233 234Used on DVB-S2. 235 236Sets DVB-S2 rolloff. 237 238The acceptable values are defined by :c:type:`fe_rolloff`. 239 240 241.. _DTV-DISEQC-SLAVE-REPLY: 242 243DTV_DISEQC_SLAVE_REPLY 244====================== 245 246Currently not implemented. 247 248 249.. _DTV-FE-CAPABILITY-COUNT: 250 251DTV_FE_CAPABILITY_COUNT 252======================= 253 254Currently not implemented. 255 256 257.. _DTV-FE-CAPABILITY: 258 259DTV_FE_CAPABILITY 260================= 261 262Currently not implemented. 263 264 265.. _DTV-DELIVERY-SYSTEM: 266 267DTV_DELIVERY_SYSTEM 268=================== 269 270Specifies the type of the delivery system. 271 272The acceptable values are defined by :c:type:`fe_delivery_system`. 273 274 275.. _DTV-ISDBT-PARTIAL-RECEPTION: 276 277DTV_ISDBT_PARTIAL_RECEPTION 278=========================== 279 280Used only on ISDB. 281 282If ``DTV_ISDBT_SOUND_BROADCASTING`` is '0' this bit field represents 283whether the channel is in partial reception mode or not. 284 285If '1' ``DTV_ISDBT_LAYERA_*`` values are assigned to the center segment 286and ``DTV_ISDBT_LAYERA_SEGMENT_COUNT`` has to be '1'. 287 288If in addition ``DTV_ISDBT_SOUND_BROADCASTING`` is '1' 289``DTV_ISDBT_PARTIAL_RECEPTION`` represents whether this ISDB-Tsb channel 290is consisting of one segment and layer or three segments and two layers. 291 292Possible values: 0, 1, -1 (AUTO) 293 294 295.. _DTV-ISDBT-SOUND-BROADCASTING: 296 297DTV_ISDBT_SOUND_BROADCASTING 298============================ 299 300Used only on ISDB. 301 302This field represents whether the other DTV_ISDBT_*-parameters are 303referring to an ISDB-T and an ISDB-Tsb channel. (See also 304``DTV_ISDBT_PARTIAL_RECEPTION``). 305 306Possible values: 0, 1, -1 (AUTO) 307 308 309.. _DTV-ISDBT-SB-SUBCHANNEL-ID: 310 311DTV_ISDBT_SB_SUBCHANNEL_ID 312========================== 313 314Used only on ISDB. 315 316This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'. 317 318(Note of the author: This might not be the correct description of the 319``SUBCHANNEL-ID`` in all details, but it is my understanding of the 320technical background needed to program a device) 321 322An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a 323set of connected ISDB-Tsb channels. In this set of channels every 324channel can be received independently. The number of connected ISDB-Tsb 325segment can vary, e.g. depending on the frequency spectrum bandwidth 326available. 327 328Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The 329broadcaster has several possibilities to put those channels in the air: 330Assuming a normal 13-segment ISDB-T spectrum he can align the 8 segments 331from position 1-8 to 5-13 or anything in between. 332 333The underlying layer of segments are sub-channels: each segment is 334consisting of several sub-channels with a predefined IDs. A sub-channel 335is used to help the demodulator to synchronize on the channel. 336 337An ISDB-T channel is always centered over all sub-channels. As for the 338example above, in ISDB-Tsb it is no longer as simple as that. 339 340``The DTV_ISDBT_SB_SUBCHANNEL_ID`` parameter is used to give the 341sub-channel ID of the segment to be demodulated. 342 343Possible values: 0 .. 41, -1 (AUTO) 344 345 346.. _DTV-ISDBT-SB-SEGMENT-IDX: 347 348DTV_ISDBT_SB_SEGMENT_IDX 349======================== 350 351Used only on ISDB. 352 353This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'. 354 355``DTV_ISDBT_SB_SEGMENT_IDX`` gives the index of the segment to be 356demodulated for an ISDB-Tsb channel where several of them are 357transmitted in the connected manner. 358 359Possible values: 0 .. ``DTV_ISDBT_SB_SEGMENT_COUNT`` - 1 360 361Note: This value cannot be determined by an automatic channel search. 362 363 364.. _DTV-ISDBT-SB-SEGMENT-COUNT: 365 366DTV_ISDBT_SB_SEGMENT_COUNT 367========================== 368 369Used only on ISDB. 370 371This field only applies if ``DTV_ISDBT_SOUND_BROADCASTING`` is '1'. 372 373``DTV_ISDBT_SB_SEGMENT_COUNT`` gives the total count of connected 374ISDB-Tsb channels. 375 376Possible values: 1 .. 13 377 378Note: This value cannot be determined by an automatic channel search. 379 380 381.. _isdb-hierq-layers: 382 383DTV-ISDBT-LAYER[A-C] parameters 384=============================== 385 386Used only on ISDB. 387 388ISDB-T channels can be coded hierarchically. As opposed to DVB-T in 389ISDB-T hierarchical layers can be decoded simultaneously. For that 390reason a ISDB-T demodulator has 3 Viterbi and 3 Reed-Solomon decoders. 391 392ISDB-T has 3 hierarchical layers which each can use a part of the 393available segments. The total number of segments over all layers has to 39413 in ISDB-T. 395 396There are 3 parameter sets, for Layers A, B and C. 397 398 399.. _DTV-ISDBT-LAYER-ENABLED: 400 401DTV_ISDBT_LAYER_ENABLED 402----------------------- 403 404Used only on ISDB. 405 406Hierarchical reception in ISDB-T is achieved by enabling or disabling 407layers in the decoding process. Setting all bits of 408``DTV_ISDBT_LAYER_ENABLED`` to '1' forces all layers (if applicable) to 409be demodulated. This is the default. 410 411If the channel is in the partial reception mode 412(``DTV_ISDBT_PARTIAL_RECEPTION`` = 1) the central segment can be decoded 413independently of the other 12 segments. In that mode layer A has to have 414a ``SEGMENT_COUNT`` of 1. 415 416In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb according 417to ``DTV_ISDBT_PARTIAL_RECEPTION``. ``SEGMENT_COUNT`` must be filled 418accordingly. 419 420Only the values of the first 3 bits are used. Other bits will be silently ignored: 421 422``DTV_ISDBT_LAYER_ENABLED`` bit 0: layer A enabled 423 424``DTV_ISDBT_LAYER_ENABLED`` bit 1: layer B enabled 425 426``DTV_ISDBT_LAYER_ENABLED`` bit 2: layer C enabled 427 428``DTV_ISDBT_LAYER_ENABLED`` bits 3-31: unused 429 430 431.. _DTV-ISDBT-LAYER-FEC: 432 433DTV_ISDBT_LAYER[A-C]_FEC 434------------------------ 435 436Used only on ISDB. 437 438The Forward Error Correction mechanism used by a given ISDB Layer, as 439defined by :c:type:`fe_code_rate`. 440 441 442Possible values are: ``FEC_AUTO``, ``FEC_1_2``, ``FEC_2_3``, ``FEC_3_4``, 443``FEC_5_6``, ``FEC_7_8`` 444 445 446.. _DTV-ISDBT-LAYER-MODULATION: 447 448DTV_ISDBT_LAYER[A-C]_MODULATION 449------------------------------- 450 451Used only on ISDB. 452 453The modulation used by a given ISDB Layer, as defined by 454:c:type:`fe_modulation`. 455 456Possible values are: ``QAM_AUTO``, ``QPSK``, ``QAM_16``, ``QAM_64``, ``DQPSK`` 457 458.. note:: 459 460 #. If layer C is ``DQPSK``, then layer B has to be ``DQPSK``. 461 462 #. If layer B is ``DQPSK`` and ``DTV_ISDBT_PARTIAL_RECEPTION``\ = 0, 463 then layer has to be ``DQPSK``. 464 465 466.. _DTV-ISDBT-LAYER-SEGMENT-COUNT: 467 468DTV_ISDBT_LAYER[A-C]_SEGMENT_COUNT 469---------------------------------- 470 471Used only on ISDB. 472 473Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO) 474 475Note: Truth table for ``DTV_ISDBT_SOUND_BROADCASTING`` and 476``DTV_ISDBT_PARTIAL_RECEPTION`` and ``LAYER[A-C]_SEGMENT_COUNT`` 477 478.. _isdbt-layer_seg-cnt-table: 479 480.. flat-table:: Truth table for ISDB-T Sound Broadcasting 481 :header-rows: 1 482 :stub-columns: 0 483 484 485 - .. row 1 486 487 - Partial Reception 488 489 - Sound Broadcasting 490 491 - Layer A width 492 493 - Layer B width 494 495 - Layer C width 496 497 - total width 498 499 - .. row 2 500 501 - 0 502 503 - 0 504 505 - 1 .. 13 506 507 - 1 .. 13 508 509 - 1 .. 13 510 511 - 13 512 513 - .. row 3 514 515 - 1 516 517 - 0 518 519 - 1 520 521 - 1 .. 13 522 523 - 1 .. 13 524 525 - 13 526 527 - .. row 4 528 529 - 0 530 531 - 1 532 533 - 1 534 535 - 0 536 537 - 0 538 539 - 1 540 541 - .. row 5 542 543 - 1 544 545 - 1 546 547 - 1 548 549 - 2 550 551 - 0 552 553 - 13 554 555 556 557.. _DTV-ISDBT-LAYER-TIME-INTERLEAVING: 558 559DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING 560-------------------------------------- 561 562Used only on ISDB. 563 564Valid values: 0, 1, 2, 4, -1 (AUTO) 565 566when DTV_ISDBT_SOUND_BROADCASTING is active, value 8 is also valid. 567 568Note: The real time interleaving length depends on the mode (fft-size). 569The values here are referring to what can be found in the 570TMCC-structure, as shown in the table below. 571 572 573.. c:type:: isdbt_layer_interleaving_table 574 575.. flat-table:: ISDB-T time interleaving modes 576 :header-rows: 1 577 :stub-columns: 0 578 579 580 - .. row 1 581 582 - ``DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING`` 583 584 - Mode 1 (2K FFT) 585 586 - Mode 2 (4K FFT) 587 588 - Mode 3 (8K FFT) 589 590 - .. row 2 591 592 - 0 593 594 - 0 595 596 - 0 597 598 - 0 599 600 - .. row 3 601 602 - 1 603 604 - 4 605 606 - 2 607 608 - 1 609 610 - .. row 4 611 612 - 2 613 614 - 8 615 616 - 4 617 618 - 2 619 620 - .. row 5 621 622 - 4 623 624 - 16 625 626 - 8 627 628 - 4 629 630 631 632.. _DTV-ATSCMH-FIC-VER: 633 634DTV_ATSCMH_FIC_VER 635------------------ 636 637Used only on ATSC-MH. 638 639Version number of the FIC (Fast Information Channel) signaling data. 640 641FIC is used for relaying information to allow rapid service acquisition 642by the receiver. 643 644Possible values: 0, 1, 2, 3, ..., 30, 31 645 646 647.. _DTV-ATSCMH-PARADE-ID: 648 649DTV_ATSCMH_PARADE_ID 650-------------------- 651 652Used only on ATSC-MH. 653 654Parade identification number 655 656A parade is a collection of up to eight MH groups, conveying one or two 657ensembles. 658 659Possible values: 0, 1, 2, 3, ..., 126, 127 660 661 662.. _DTV-ATSCMH-NOG: 663 664DTV_ATSCMH_NOG 665-------------- 666 667Used only on ATSC-MH. 668 669Number of MH groups per MH subframe for a designated parade. 670 671Possible values: 1, 2, 3, 4, 5, 6, 7, 8 672 673 674.. _DTV-ATSCMH-TNOG: 675 676DTV_ATSCMH_TNOG 677--------------- 678 679Used only on ATSC-MH. 680 681Total number of MH groups including all MH groups belonging to all MH 682parades in one MH subframe. 683 684Possible values: 0, 1, 2, 3, ..., 30, 31 685 686 687.. _DTV-ATSCMH-SGN: 688 689DTV_ATSCMH_SGN 690-------------- 691 692Used only on ATSC-MH. 693 694Start group number. 695 696Possible values: 0, 1, 2, 3, ..., 14, 15 697 698 699.. _DTV-ATSCMH-PRC: 700 701DTV_ATSCMH_PRC 702-------------- 703 704Used only on ATSC-MH. 705 706Parade repetition cycle. 707 708Possible values: 1, 2, 3, 4, 5, 6, 7, 8 709 710 711.. _DTV-ATSCMH-RS-FRAME-MODE: 712 713DTV_ATSCMH_RS_FRAME_MODE 714------------------------ 715 716Used only on ATSC-MH. 717 718Reed Solomon (RS) frame mode. 719 720The acceptable values are defined by :c:type:`atscmh_rs_frame_mode`. 721 722 723.. _DTV-ATSCMH-RS-FRAME-ENSEMBLE: 724 725DTV_ATSCMH_RS_FRAME_ENSEMBLE 726---------------------------- 727 728Used only on ATSC-MH. 729 730Reed Solomon (RS) frame ensemble. 731 732The acceptable values are defined by :c:type:`atscmh_rs_frame_ensemble`. 733 734 735.. _DTV-ATSCMH-RS-CODE-MODE-PRI: 736 737DTV_ATSCMH_RS_CODE_MODE_PRI 738--------------------------- 739 740Used only on ATSC-MH. 741 742Reed Solomon (RS) code mode (primary). 743 744The acceptable values are defined by :c:type:`atscmh_rs_code_mode`. 745 746 747.. _DTV-ATSCMH-RS-CODE-MODE-SEC: 748 749DTV_ATSCMH_RS_CODE_MODE_SEC 750--------------------------- 751 752Used only on ATSC-MH. 753 754Reed Solomon (RS) code mode (secondary). 755 756The acceptable values are defined by :c:type:`atscmh_rs_code_mode`. 757 758 759.. _DTV-ATSCMH-SCCC-BLOCK-MODE: 760 761DTV_ATSCMH_SCCC_BLOCK_MODE 762-------------------------- 763 764Used only on ATSC-MH. 765 766Series Concatenated Convolutional Code Block Mode. 767 768The acceptable values are defined by :c:type:`atscmh_sccc_block_mode`. 769 770 771.. _DTV-ATSCMH-SCCC-CODE-MODE-A: 772 773DTV_ATSCMH_SCCC_CODE_MODE_A 774--------------------------- 775 776Used only on ATSC-MH. 777 778Series Concatenated Convolutional Code Rate. 779 780The acceptable values are defined by :c:type:`atscmh_sccc_code_mode`. 781 782.. _DTV-ATSCMH-SCCC-CODE-MODE-B: 783 784DTV_ATSCMH_SCCC_CODE_MODE_B 785--------------------------- 786 787Used only on ATSC-MH. 788 789Series Concatenated Convolutional Code Rate. 790 791Possible values are the same as documented on enum 792:c:type:`atscmh_sccc_code_mode`. 793 794 795.. _DTV-ATSCMH-SCCC-CODE-MODE-C: 796 797DTV_ATSCMH_SCCC_CODE_MODE_C 798--------------------------- 799 800Used only on ATSC-MH. 801 802Series Concatenated Convolutional Code Rate. 803 804Possible values are the same as documented on enum 805:c:type:`atscmh_sccc_code_mode`. 806 807 808.. _DTV-ATSCMH-SCCC-CODE-MODE-D: 809 810DTV_ATSCMH_SCCC_CODE_MODE_D 811--------------------------- 812 813Used only on ATSC-MH. 814 815Series Concatenated Convolutional Code Rate. 816 817Possible values are the same as documented on enum 818:c:type:`atscmh_sccc_code_mode`. 819 820 821.. _DTV-API-VERSION: 822 823DTV_API_VERSION 824=============== 825 826Returns the major/minor version of the Digital TV API 827 828 829.. _DTV-CODE-RATE-HP: 830 831DTV_CODE_RATE_HP 832================ 833 834Used on terrestrial transmissions. 835 836The acceptable values are defined by :c:type:`fe_transmit_mode`. 837 838 839.. _DTV-CODE-RATE-LP: 840 841DTV_CODE_RATE_LP 842================ 843 844Used on terrestrial transmissions. 845 846The acceptable values are defined by :c:type:`fe_transmit_mode`. 847 848 849.. _DTV-GUARD-INTERVAL: 850 851DTV_GUARD_INTERVAL 852================== 853 854The acceptable values are defined by :c:type:`fe_guard_interval`. 855 856.. note:: 857 858 #. If ``DTV_GUARD_INTERVAL`` is set the ``GUARD_INTERVAL_AUTO`` the 859 hardware will try to find the correct guard interval (if capable) and 860 will use TMCC to fill in the missing parameters. 861 #. Interval ``GUARD_INTERVAL_1_64`` is used only for DVB-C2. 862 #. Interval ``GUARD_INTERVAL_1_128`` is used for both DVB-C2 and DVB_T2. 863 #. Intervals ``GUARD_INTERVAL_19_128`` and ``GUARD_INTERVAL_19_256`` are 864 used only for DVB-T2. 865 #. Intervals ``GUARD_INTERVAL_PN420``, ``GUARD_INTERVAL_PN595`` and 866 ``GUARD_INTERVAL_PN945`` are used only for DMTB at the present. 867 On such standard, only those intervals and ``GUARD_INTERVAL_AUTO`` 868 are valid. 869 870.. _DTV-TRANSMISSION-MODE: 871 872DTV_TRANSMISSION_MODE 873===================== 874 875 876Used only on OFTM-based standards, e. g. DVB-T/T2, ISDB-T, DTMB. 877 878Specifies the FFT size (with corresponds to the approximate number of 879carriers) used by the standard. 880 881The acceptable values are defined by :c:type:`fe_transmit_mode`. 882 883.. note:: 884 885 #. ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called 886 **mode** on such standard, and are numbered from 1 to 3: 887 888 ==== ======== ======================== 889 Mode FFT size Transmission mode 890 ==== ======== ======================== 891 1 2K ``TRANSMISSION_MODE_2K`` 892 2 4K ``TRANSMISSION_MODE_4K`` 893 3 8K ``TRANSMISSION_MODE_8K`` 894 ==== ======== ======================== 895 896 #. If ``DTV_TRANSMISSION_MODE`` is set the ``TRANSMISSION_MODE_AUTO`` 897 the hardware will try to find the correct FFT-size (if capable) and 898 will use TMCC to fill in the missing parameters. 899 900 #. DVB-T specifies 2K and 8K as valid sizes. 901 902 #. DVB-T2 specifies 1K, 2K, 4K, 8K, 16K and 32K. 903 904 #. DTMB specifies C1 and C3780. 905 906 907.. _DTV-HIERARCHY: 908 909DTV_HIERARCHY 910============= 911 912Used only on DVB-T and DVB-T2. 913 914Frontend hierarchy. 915 916The acceptable values are defined by :c:type:`fe_hierarchy`. 917 918 919.. _DTV-STREAM-ID: 920 921DTV_STREAM_ID 922============= 923 924Used on DVB-C2, DVB-S2, DVB-T2 and ISDB-S. 925 926DVB-C2, DVB-S2, DVB-T2 and ISDB-S support the transmission of several 927streams on a single transport stream. This property enables the digital 928TV driver to handle substream filtering, when supported by the hardware. 929By default, substream filtering is disabled. 930 931For DVB-C2, DVB-S2 and DVB-T2, the valid substream id range is from 0 to 932255. 933 934For ISDB, the valid substream id range is from 1 to 65535. 935 936To disable it, you should use the special macro NO_STREAM_ID_FILTER. 937 938Note: any value outside the id range also disables filtering. 939 940 941.. _DTV-DVBT2-PLP-ID-LEGACY: 942 943DTV_DVBT2_PLP_ID_LEGACY 944======================= 945 946Obsolete, replaced with DTV_STREAM_ID. 947 948 949.. _DTV-ENUM-DELSYS: 950 951DTV_ENUM_DELSYS 952=============== 953 954A Multi standard frontend needs to advertise the delivery systems 955provided. Applications need to enumerate the provided delivery systems, 956before using any other operation with the frontend. Prior to its 957introduction, FE_GET_INFO was used to determine a frontend type. A 958frontend which provides more than a single delivery system, 959FE_GET_INFO doesn't help much. Applications which intends to use a 960multistandard frontend must enumerate the delivery systems associated 961with it, rather than trying to use FE_GET_INFO. In the case of a 962legacy frontend, the result is just the same as with FE_GET_INFO, but 963in a more structured format. 964 965The acceptable values are defined by :c:type:`fe_delivery_system`. 966 967 968.. _DTV-INTERLEAVING: 969 970DTV_INTERLEAVING 971================ 972 973Time interleaving to be used. 974 975The acceptable values are defined by :c:type:`fe_interleaving`. 976 977 978.. _DTV-LNA: 979 980DTV_LNA 981======= 982 983Low-noise amplifier. 984 985Hardware might offer controllable LNA which can be set manually using 986that parameter. Usually LNA could be found only from terrestrial devices 987if at all. 988 989Possible values: 0, 1, LNA_AUTO 990 9910, LNA off 992 9931, LNA on 994 995use the special macro LNA_AUTO to set LNA auto 996 997 998.. _DTV-SCRAMBLING-SEQUENCE-INDEX: 999 1000DTV_SCRAMBLING_SEQUENCE_INDEX 1001============================= 1002 1003Used on DVB-S2. 1004 1005This 18 bit field, when present, carries the index of the DVB-S2 physical 1006layer scrambling sequence as defined in clause 5.5.4 of EN 302 307. 1007There is no explicit signalling method to convey scrambling sequence index 1008to the receiver. If S2 satellite delivery system descriptor is available 1009it can be used to read the scrambling sequence index (EN 300 468 table 41). 1010 1011By default, gold scrambling sequence index 0 is used. 1012 1013The valid scrambling sequence index range is from 0 to 262142. 1014