2.5.3. ioctl FE_GET_INFO¶
2.5.3.1. Name¶
FE_GET_INFO - Query DVB frontend capabilities and returns information about the - front-end. This call only requires read-only access to the device
2.5.3.3. Arguments¶
fd- File descriptor returned by open().
request- FE_GET_INFO
argp- pointer to struct struct dvb_frontend_info
2.5.3.4. Description¶
All DVB frontend devices support the FE_GET_INFO ioctl. It is used
to identify kernel devices compatible with this specification and to
obtain information about driver and hardware capabilities. The ioctl
takes a pointer to dvb_frontend_info which is filled by the driver.
When the driver is not compatible with this specification the ioctl
returns an error.
2.5.3.5. struct dvb_frontend_info¶
| char | name[128] | Name of the frontend |
| fe_type_t | type | DEPRECATED. DVBv3 type. Should not be used on modern programs, as a frontend may have more than one type. So, the DVBv5 API should be used instead to enumerate and select the frontend type. |
| uint32_t | frequency_min | Minimal frequency supported by the frontend |
| uint32_t | frequency_max | Maximal frequency supported by the frontend |
| uint32_t | frequency_stepsize | Frequency step - all frequencies are multiple of this value |
| uint32_t | frequency_tolerance | Tolerance of the frequency |
| uint32_t | symbol_rate_min | Minimal symbol rate (for Cable/Satellite systems), in bauds |
| uint32_t | symbol_rate_max | Maximal symbol rate (for Cable/Satellite systems), in bauds |
| uint32_t | symbol_rate_tolerance | Maximal symbol rate tolerance, in ppm |
| uint32_t | notifier_delay | DEPRECATED. Not used by any driver. |
| enum fe_caps | caps | Capabilities supported by the frontend |
Note
The frequencies are specified in Hz for Terrestrial and Cable systems. They’re specified in kHz for Satellite systems
2.5.3.6. frontend capabilities¶
Capabilities describe what a frontend can do. Some capabilities are supported only on some specific frontend types.
| ID | Description |
|---|---|
|
There’s something wrong at the frontend, and it can’t report its capabilities |
|
The frontend is capable of auto-detecting inversion |
|
The frontend supports FEC 1/2 |
|
The frontend supports FEC 2/3 |
|
The frontend supports FEC 3/4 |
|
The frontend supports FEC 4/5 |
|
The frontend supports FEC 5/6 |
|
The frontend supports FEC 6/7 |
|
The frontend supports FEC 7/8 |
|
The frontend supports FEC 8/9 |
|
The frontend can autodetect FEC. |
|
The frontend supports QPSK modulation |
|
The frontend supports 16-QAM modulation |
|
The frontend supports 32-QAM modulation |
|
The frontend supports 64-QAM modulation |
|
The frontend supports 128-QAM modulation |
|
The frontend supports 256-QAM modulation |
|
The frontend can autodetect modulation |
|
The frontend can autodetect the transmission mode |
|
The frontend can autodetect the bandwidth |
|
The frontend can autodetect the guard interval |
|
The frontend can autodetect hierarch |
|
The frontend supports 8-VSB modulation |
|
The frontend supports 16-VSB modulation |
|
Currently, unused |
|
The frontend supports multistream filtering |
|
The frontend supports turbo FEC modulation |
|
The frontend supports “2nd generation modulation” (DVB-S2/T2)> |
|
Not supported anymore, don’t use it |
|
The frontend can recover from a cable unplug automatically |
|
The frontend can stop spurious TS data output |
2.5.3.7. Return Value¶
On success 0 is returned, on error -1 and the errno variable is set
appropriately. The generic error codes are described at the
Generic Error Codes chapter.