6.1.1.1. Frontend type

For historical reasons, frontend types are named by the type of modulation used in transmission. The fontend types are given by fe_type_t type, defined as:

type fe_type
Frontend types

fe_type

Description

DTV_DELIVERY_SYSTEM equivalent type

FE_QPSK

For DVB-S standard

SYS_DVBS

FE_QAM

For DVB-C annex A standard

SYS_DVBC_ANNEX_A

FE_OFDM

For DVB-T standard

SYS_DVBT

FE_ATSC

For ATSC standard (terrestrial) or for DVB-C Annex B (cable) used in US.

SYS_ATSC (terrestrial) or SYS_DVBC_ANNEX_B (cable)

Newer formats like DVB-S2, ISDB-T, ISDB-S and DVB-T2 are not described at the above, as they’re supported via the new FE_GET_PROPERTY/FE_GET_SET_PROPERTY ioctl’s, using the DTV_DELIVERY_SYSTEM parameter.

In the old days, struct dvb_frontend_info used to contain fe_type_t field to indicate the delivery systems, filled with either FE_QPSK, FE_QAM, FE_OFDM or FE_ATSC. While this is still filled to keep backward compatibility, the usage of this field is deprecated, as it can report just one delivery system, but some devices support multiple delivery systems. Please use DTV_ENUM_DELSYS instead.

On devices that support multiple delivery systems, struct dvb_frontend_info::fe_type_t is filled with the currently standard, as selected by the last call to FE_SET_PROPERTY using the DTV_DELIVERY_SYSTEM property.