Get or set the current hardware device information into the struct radio_info structure.
struct radio_info {
int mute;
int volume;
int stereo;
int rfreq; /* reference frequency */
int lock; /* locking field strength */
uint32_t freq; /* in kHz */
uint32_t caps; /* card capabilities */
#define RADIO_CAPS_DETECT_STEREO (1<<0)
#define RADIO_CAPS_DETECT_SIGNAL (1<<1)
#define RADIO_CAPS_SET_MONO (1<<2)
#define RADIO_CAPS_HW_SEARCH (1<<3)
#define RADIO_CAPS_HW_AFC (1<<4)
#define RADIO_CAPS_REFERENCE_FREQ (1<<5)
#define RADIO_CAPS_LOCK_SENSITIVITY (1<<6)
#define RADIO_CARD_TYPE (0xFF<<16)
uint32_t info;
#define RADIO_INFO_STEREO (1<<0)
#define RADIO_INFO_SIGNAL (1<<1)
};
The
mute field is a boolean.
The
volume field holds the card volume information and can be at most 255.
The
stereo field is a boolean.
The
rfreq holds information about the card reference frequency (not all cards support this feature).
The
lock field holds information about the card locking field strength during an automatic search for cards that support this feature.
The
freq field is the frequency in kHz the card is tuned to.
The
caps field is read-only and describes the card capabilities. The capabilities can have following values:
RADIO_CAPS_DETECT_STEREO
The device can determine is it tuned to a stereo signal.
RADIO_CAPS_DETECT_SIGNAL
The device can determine is it tuned or not.
RADIO_CAPS_SET_MONO
The device capable to forcible set its output to mono.
RADIO_CAPS_HW_SEARCH
The device can do hardware search.
RADIO_CAPS_HW_AFC
The device has an internal hardware automatic frequency control.
RADIO_CAPS_REFERENCE_FREQ
The device allow to change the reference frequency of a received signal.
RADIO_CAPS_LOCK_SENSITIVITY
The device allow to change the station lock sensitivity used during search operation.
RADIO_CARD_TYPE
Some cards have several different incarnations. This allow to determine the variant of the card. Currently not used.
The
info field is read-only and describes the current state of the card - tuned/not tuned, stereo signal/mono signal.
RADIO_INFO_STEREO
Informs whether the device receives a stereo or mono signal.
RADIO_INFO_SIGNAL
Informs whether the device receives a valid signal or noise.