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// (C) 2016 Julian Picht, MIT/x11 License.
//
//All MIT/x11 Licensed Code in this file may be relicensed freely under the GPL or LGPL licenses.
#ifndef DISAMBIGUATOR_H
#define DISAMBIGUATOR_H
// Determines the number of samples stored in the disambiguator struct.
// Has to be higher than the maximum number of pulses expected between sync pulses.
#define DIS_NUM_VALUES 48
#define DIS_NUM_PULSES_BEFORE_LOCK 30
#include <stdint.h>
/**
* internal disambiguator state
*/
typedef enum {
D_STATE_INVALID = 0,
D_STATE_LOCKED = 1,
D_STATE_UNLOCKED = -1,
} dis_state;
/**
* classification result
*/
typedef enum {
P_UNKNOWN = 0,
P_SYNC = 1,
P_SWEEP = 2,
} pulse_type;
/**
* internal state of the disambiguator
*/
struct disambiguator {
// the timestamps of the recorded pulses
uint32_t times[DIS_NUM_VALUES];
// countes how many sync pulses we have seen, that match the time offset at the same offset
uint16_t scores[DIS_NUM_VALUES];
// current state
dis_state state;
// last sync pulse time
uint32_t last;
// the absolute maximum counter value
int max_confidence;
// the last code type seen
char code;
};
/**
* Initialize a new disambiguator. calloc or memset with 0x00 will work just as well.
*
* @param d Pointer to the struct
*/
void disambiguator_init( struct disambiguator * d);
/**
* Feed in one pulse to have if classified.
*
* @param d Pointer to disambiguator state
* @param time Rising edge of the pulse
* @param length Length of the pulse
* @return Classification result
*/
pulse_type disambiguator_step( struct disambiguator * d, uint32_t time, int length);
#endif /* DISAMBIGUATOR_H */
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