Digital TV property parameters

DTV_UNDEFINED

Used internally. A GET/SET operation for it won't change or return anything.

DTV_TUNE

Interpret the cache of data, build either a traditional frontend tunerequest so we can pass validation in the FE_SET_FRONTEND ioctl.

DTV_CLEAR

Reset a cache of data specific to the frontend here. This does not effect hardware.

DTV_FREQUENCY

Frequency of the digital TV transponder/channel.

DTV_MODULATION

Specifies the frontend modulation type for delivery systems that supports more than one modulation type. The modulation can be one of the types defined by enum :c:type:`fe_modulation`.

Modulation property

Most of the digital TV standards currently offers more than one possible modulation (sometimes called as "constellation" on some standards). This enum contains the values used by the Kernel. Please note that not all modulations are supported by a given standard.

DTV_BANDWIDTH_HZ

Bandwidth for the channel, in HZ.

Possible values: 1712000, 5000000, 6000000, 7000000, 8000000, 10000000.

DTV_INVERSION

Specifies if the frontend should do spectral inversion or not.

enum fe_modulation: Frontend spectral inversion

This parameter indicates if spectral inversion should be presumed or not. In the automatic setting (INVERSION_AUTO) the hardware will try to figure out the correct setting by itself. If the hardware doesn't support, the DVB core will try to lock at the carrier first with inversion off. If it fails, it will try to enable inversion.

DTV_DISEQC_MASTER

Currently not implemented.

DTV_SYMBOL_RATE

Digital TV symbol rate, in bauds (symbols/second). Used on cable standards.

DTV_INNER_FEC

Used cable/satellite transmissions. The acceptable values are:

enum fe_code_rate: type of the Forward Error Correction.

DTV_VOLTAGE

The voltage is usually used with non-DiSEqC capable LNBs to switch the polarzation (horizontal/vertical). When using DiSEqC epuipment this voltage has to be switched consistently to the DiSEqC commands as described in the DiSEqC spec.

DTV_TONE

Currently not used.

DTV_PILOT

Sets DVB-S2 pilot

fe_pilot type

DTV_ROLLOFF

Sets DVB-S2 rolloff

fe_rolloff type

DTV_DISEQC_SLAVE_REPLY

Currently not implemented.

DTV_FE_CAPABILITY_COUNT

Currently not implemented.

DTV_FE_CAPABILITY

Currently not implemented.

DTV_DELIVERY_SYSTEM

Specifies the type of Delivery system

fe_delivery_system type

Possible values:

DTV_ISDBT_PARTIAL_RECEPTION

If DTV_ISDBT_SOUND_BROADCASTING is '0' this bit-field represents whether the channel is in partial reception mode or not.

If '1' DTV_ISDBT_LAYERA_* values are assigned to the center segment and DTV_ISDBT_LAYERA_SEGMENT_COUNT has to be '1'.

If in addition DTV_ISDBT_SOUND_BROADCASTING is '1' DTV_ISDBT_PARTIAL_RECEPTION represents whether this ISDB-Tsb channel is consisting of one segment and layer or three segments and two layers.

Possible values: 0, 1, -1 (AUTO)

DTV_ISDBT_SOUND_BROADCASTING

This field represents whether the other DTV_ISDBT_*-parameters are referring to an ISDB-T and an ISDB-Tsb channel. (See also DTV_ISDBT_PARTIAL_RECEPTION).

Possible values: 0, 1, -1 (AUTO)

DTV_ISDBT_SB_SUBCHANNEL_ID

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

(Note of the author: This might not be the correct description of the SUBCHANNEL-ID in all details, but it is my understanding of the technical background needed to program a device)

An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a set of connected ISDB-Tsb channels. In this set of channels every channel can be received independently. The number of connected ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum bandwidth available.

Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The broadcaster has several possibilities to put those channels in the air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8 segments from position 1-8 to 5-13 or anything in between.

The underlying layer of segments are subchannels: each segment is consisting of several subchannels with a predefined IDs. A sub-channel is used to help the demodulator to synchronize on the channel.

An ISDB-T channel is always centered over all sub-channels. As for the example above, in ISDB-Tsb it is no longer as simple as that.

The DTV_ISDBT_SB_SUBCHANNEL_ID parameter is used to give the sub-channel ID of the segment to be demodulated.

Possible values: 0 .. 41, -1 (AUTO)

DTV_ISDBT_SB_SEGMENT_IDX

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_IDX gives the index of the segment to be demodulated for an ISDB-Tsb channel where several of them are transmitted in the connected manner.

Possible values: 0 .. DTV_ISDBT_SB_SEGMENT_COUNT - 1

Note: This value cannot be determined by an automatic channel search.

DTV_ISDBT_SB_SEGMENT_COUNT

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_COUNT gives the total count of connected ISDB-Tsb channels.

Possible values: 1 .. 13

Note: This value cannot be determined by an automatic channel search.

DTV-ISDBT-LAYER[A-C] parameters

ISDB-T channels can be coded hierarchically. As opposed to DVB-T in ISDB-T hierarchical layers can be decoded simultaneously. For that reason a ISDB-T demodulator has 3 Viterbi and 3 Reed-Solomon decoders.

ISDB-T has 3 hierarchical layers which each can use a part of the available segments. The total number of segments over all layers has to 13 in ISDB-T.

There are 3 parameter sets, for Layers A, B and C.

DTV_ISDBT_LAYER_ENABLED

Hierarchical reception in ISDB-T is achieved by enabling or disabling layers in the decoding process. Setting all bits of DTV_ISDBT_LAYER_ENABLED to '1' forces all layers (if applicable) to be demodulated. This is the default.

If the channel is in the partial reception mode (DTV_ISDBT_PARTIAL_RECEPTION = 1) the central segment can be decoded independently of the other 12 segments. In that mode layer A has to have a SEGMENT_COUNT of 1.

In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb according to DTV_ISDBT_PARTIAL_RECEPTION. SEGMENT_COUNT must be filled accordingly.

Only the values of the first 3 bits are used. Other bits will be silently ignored:

DTV_ISDBT_LAYER_ENABLED bit 0: layer A enabled

DTV_ISDBT_LAYER_ENABLED bit 1: layer B enabled

DTV_ISDBT_LAYER_ENABLED bit 2: layer C enabled

DTV_ISDBT_LAYER_ENABLED bits 3-31: unused

DTV_ISDBT_LAYER[A-C]_FEC

Possible values: FEC_AUTO, FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8

DTV_ISDBT_LAYER[A-C]_MODULATION

Possible values: QAM_AUTO, QPSK, QAM_16, QAM_64, DQPSK

Note: If layer C is DQPSK layer B has to be DQPSK. If layer B is DQPSK and DTV_ISDBT_PARTIAL_RECEPTION=0 layer has to be DQPSK.

DTV_ISDBT_LAYER[A-C]_SEGMENT_COUNT

Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)

Note: Truth table for DTV_ISDBT_SOUND_BROADCASTING and DTV_ISDBT_PARTIAL_RECEPTION and LAYER[A-C]_SEGMENT_COUNT

DTV_ISDBT_LAYER[A-C]_TIME_INTERLEAVING

Valid values: 0, 1, 2, 4, -1 (AUTO)

when DTV_ISDBT_SOUND_BROADCASTING is active, value 8 is also valid.

Note: The real time interleaving length depends on the mode (fft-size). The values here are referring to what can be found in the TMCC-structure, as shown in the table below.

DTV_ATSCMH_FIC_VER

Version number of the FIC (Fast Information Channel) signaling data.

FIC is used for relaying information to allow rapid service acquisition by the receiver.

Possible values: 0, 1, 2, 3, ..., 30, 31

DTV_ATSCMH_PARADE_ID

Parade identification number

A parade is a collection of up to eight MH groups, conveying one or two ensembles.

Possible values: 0, 1, 2, 3, ..., 126, 127

DTV_ATSCMH_NOG

Number of MH groups per MH subframe for a designated parade.

Possible values: 1, 2, 3, 4, 5, 6, 7, 8

DTV_ATSCMH_TNOG

Total number of MH groups including all MH groups belonging to all MH parades in one MH subframe.

Possible values: 0, 1, 2, 3, ..., 30, 31

DTV_ATSCMH_SGN

Start group number.

Possible values: 0, 1, 2, 3, ..., 14, 15

DTV_ATSCMH_PRC

Parade repetition cycle.

Possible values: 1, 2, 3, 4, 5, 6, 7, 8

DTV_ATSCMH_RS_FRAME_MODE

Reed Solomon (RS) frame mode.

Possible values are:

DTV_ATSCMH_RS_FRAME_ENSEMBLE

Reed Solomon(RS) frame ensemble.

Possible values are:

DTV_ATSCMH_RS_CODE_MODE_PRI

Reed Solomon (RS) code mode (primary).

Possible values are:

DTV_ATSCMH_RS_CODE_MODE_SEC

Reed Solomon (RS) code mode (secondary).

Possible values are the same as documented on enum :c:type:`atscmh_rs_code_mode`:

DTV_ATSCMH_SCCC_BLOCK_MODE

Series Concatenated Convolutional Code Block Mode.

Possible values are:

DTV_ATSCMH_SCCC_CODE_MODE_A

Series Concatenated Convolutional Code Rate.

Possible values are:

DTV_ATSCMH_SCCC_CODE_MODE_B

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum :c:type:`atscmh_sccc_code_mode`.

DTV_ATSCMH_SCCC_CODE_MODE_C

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum :c:type:`atscmh_sccc_code_mode`.

DTV_ATSCMH_SCCC_CODE_MODE_D

Series Concatenated Convolutional Code Rate.

Possible values are the same as documented on enum :c:type:`atscmh_sccc_code_mode`.

DTV_API_VERSION

Returns the major/minor version of the DVB API

DTV_CODE_RATE_HP

Used on terrestrial transmissions. The acceptable values are the ones described at :c:type:`fe_transmit_mode`.

DTV_CODE_RATE_LP

Used on terrestrial transmissions. The acceptable values are the ones described at :c:type:`fe_transmit_mode`.

DTV_GUARD_INTERVAL

Possible values are:

Modulation guard interval

Notes:

1) If DTV_GUARD_INTERVAL is set the GUARD_INTERVAL_AUTO the hardware will try to find the correct guard interval (if capable) and will use TMCC to fill in the missing parameters.

2) Intervals 1/128, 19/128 and 19/256 are used only for DVB-T2 at present

3. DTMB specifies PN420, PN595 and PN945.

DTV_TRANSMISSION_MODE

Specifies the number of carriers used by the standard. This is used only on OFTM-based standards, e. g. DVB-T/T2, ISDB-T, DTMB

enum fe_transmit_mode: Number of carriers per channel

Notes:

1) ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called 'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K

2) If DTV_TRANSMISSION_MODE is set the TRANSMISSION_MODE_AUTO the hardware will try to find the correct FFT-size (if capable) and will use TMCC to fill in the missing parameters.

3. DVB-T specifies 2K and 8K as valid sizes.
4. DVB-T2 specifies 1K, 2K, 4K, 8K, 16K and 32K.
5. DTMB specifies C1 and C3780.

DTV_HIERARCHY

Frontend hierarchy

Frontend hierarchy

DTV_STREAM_ID

DVB-S2, DVB-T2 and ISDB-S support the transmission of several streams on a single transport stream. This property enables the DVB driver to handle substream filtering, when supported by the hardware. By default, substream filtering is disabled.

For DVB-S2 and DVB-T2, the valid substream id range is from 0 to 255.

For ISDB, the valid substream id range is from 1 to 65535.

To disable it, you should use the special macro NO_STREAM_ID_FILTER.

Note: any value outside the id range also disables filtering.

DTV_DVBT2_PLP_ID_LEGACY

Obsolete, replaced with DTV_STREAM_ID.

DTV_ENUM_DELSYS

A Multi standard frontend needs to advertise the delivery systems provided. Applications need to enumerate the provided delivery systems, before using any other operation with the frontend. Prior to it's introduction, FE_GET_INFO was used to determine a frontend type. A frontend which provides more than a single delivery system, FE_GET_INFO doesn't help much. Applications which intends to use a multistandard frontend must enumerate the delivery systems associated with it, rather than trying to use FE_GET_INFO. In the case of a legacy frontend, the result is just the same as with FE_GET_INFO, but in a more structured format

DTV_INTERLEAVING

Time interleaving to be used. Currently, used only on DTMB.

DTV_LNA

Low-noise amplifier.

Hardware might offer controllable LNA which can be set manually using that parameter. Usually LNA could be found only from terrestrial devices if at all.

Possible values: 0, 1, LNA_AUTO

0, LNA off

1, LNA on

use the special macro LNA_AUTO to set LNA auto