Chapter 9. DVB Frontend API

Chapter 9. DVB Frontend API
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Table of Contents

Querying frontend information

Querying frontend status and statistics

DVB Frontend properties

struct dtv_stats
struct dtv_fe_stats
struct dtv_property
struct dtv_properties
Property types
Digital TV property parameters
Frontend statistics indicators
Properties used on terrestrial delivery systems
Properties used on cable delivery systems
Properties used on satellite delivery systems

Frontend Function Calls

DVB frontend open() — Open a frontend device
DVB frontend close() — Close a frontend device
ioctl FE_GET_INFO — Query DVB frontend capabilities and returns information about the front-end. This call only requires read-only access to the device
ioctl FE_READ_STATUS — Returns status information about the front-end. This call only requires read-only access to the device
ioctl FE_SET_PROPERTY, FE_GET_PROPERTY — FE_SET_PROPERTY sets one or more frontend properties. FE_GET_PROPERTY returns one or more frontend properties.
ioctl FE_DISEQC_RESET_OVERLOAD — Restores the power to the antenna subsystem, if it was powered off due to power overload.
ioctl FE_DISEQC_SEND_MASTER_CMD — Sends a DiSEqC command
ioctl FE_DISEQC_RECV_SLAVE_REPLY — Receives reply from a DiSEqC 2.0 command
ioctl FE_DISEQC_SEND_BURST — Sends a 22KHz tone burst for 2x1 mini DiSEqC satellite selection.
ioctl FE_SET_TONE — Sets/resets the generation of the continuous 22kHz tone.
ioctl FE_SET_VOLTAGE — Allow setting the DC level sent to the antenna subsystem.
ioctl FE_ENABLE_HIGH_LNB_VOLTAGE — Select output DC level between normal LNBf voltages or higher LNBf voltages.
ioctl FE_SET_FRONTEND_TUNE_MODE — Allow setting tuner mode flags to the frontend.

DVB Frontend legacy API (a. k. a. DVBv3)

Frontend Legacy Data Types
Frontend Legacy Function Calls

The DVB frontend API was designed to support three types of delivery systems:

Terrestrial systems: DVB-T, DVB-T2, ATSC, ATSC M/H, ISDB-T, DVB-H, DTMB, CMMB
Cable systems: DVB-C Annex A/C, ClearQAM (DVB-C Annex B), ISDB-C
Satellite systems: DVB-S, DVB-S2, DVB Turbo, ISDB-S, DSS

The DVB frontend controls several sub-devices including:

Tuner
Digital TV demodulator
Low noise amplifier (LNA)
Satellite Equipment Control (SEC) hardware (only for Satellite).

The frontend can be accessed through /dev/dvb/adapter?/frontend?. Data types and ioctl definitions can be accessed by including linux/dvb/frontend.h in your application.

NOTE: Transmission via the internet (DVB-IP) is not yet handled by this API but a future extension is possible.

On Satellite systems, the API support for the Satellite Equipment Control (SEC) allows to power control and to send/receive signals to control the antenna subsystem, selecting the polarization and choosing the Intermediate Frequency IF) of the Low Noise Block Converter Feed Horn (LNBf). It supports the DiSEqC and V-SEC protocols. The DiSEqC (digital SEC) specification is available at Eutelsat.

Querying frontend information

Usually, the first thing to do when the frontend is opened is to check the frontend capabilities. This is done using FE_GET_INFO. This ioctl will enumerate the DVB API version and other characteristics about the frontend, and can be opened either in read only or read/write mode.

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