lasp/lasp/c/lasp_siggen.h

101 lines
2.8 KiB
C

// lasp_siggen.h
//
// Author: J.A. de Jong - ASCEE
//
// Description:
// Header file for signal generation routines
//
//////////////////////////////////////////////////////////////////////
#pragma once
#ifndef LASP_SIGGEN_H
#define LASP_SIGGEN_H
#include "lasp_mat.h"
#include "lasp_sosfilterbank.h"
// Define this flag to repeat a forward sweep only, or backward only. If not
// set, we do a continuous sweep
#define SWEEP_FLAG_FORWARD 1
#define SWEEP_FLAG_BACKWARD 2
// Types of sweeps
#define SWEEP_FLAG_LINEAR 4
#define SWEEP_FLAG_EXPONENTIAL 8
typedef struct Siggen Siggen;
/**
* Create a sine wave signal generator
*
* @param[in] fs: Sampling frequency [Hz]
* @param[in] level: Relative level in [dB], should be between -inf and 0
* @param[freq] Sine wave frequency [Hz]
*/
Siggen* Siggen_Sinewave_create(const d fs,const d freq,const d level_dB);
/**
* Create a Noise signal generator. If no Sosfilterbank is provided, it will
* create white noise. Otherwise, the noise is 'colored' using the filterbank
* given in the constructor. Note that the pointer to this filterbank is
* *STOLEN*!.
*
* @param[in] fs: Sampling frequency [Hz]
* @param[in] level_dB: Relative level [dB]
* @param[in]
*
* @return Siggen* handle
*/
Siggen* Siggen_Noise_create(const d fs, const d level_dB, Sosfilterbank* colorfilter);
/**
* Set the level of the signal generator
* @param[in] Siggen* Signal generator handle
*
* @param[in] new_level_dB The new level, in dBFS
*/
void Siggen_setLevel(Siggen*, const d new_level_dB);
/**
* Obtain the repetition period for a periodic excitation.
* @param[in] Siggen* Signal generator handle
*
* @param[out] N The amount of samples in one period, returns 0 if the signal
* does not repeat.
*/
us Siggen_getN(const Siggen*);
/**
* Create a forward sweep
*
* @param[in] fs: Sampling frequency [Hz]
* @param[in] fl: Lower frequency [Hz]
* @param[in] fl: Upper frequency [Hz]
* @param[in] Ts: Sweep time [s]
* @param[in] Tq: Quescent tail time [s]. Choose this value long enough to
* avoid temporal aliasing in case of measuring impulse responses.
* @param[in] sweep_flags: Sweep period [s]
* @param[in] level: Relative level in [dB], should be between -inf and 0
* @return Siggen* handle
*/
Siggen* Siggen_Sweep_create(const d fs,const d fl,const d fu,
const d Ts, const d Tq, const us sweep_flags,
const d level);
/**
* Obtain a new piece of signal
*
* @param[in] Siggen* Signal generator handle
* @param[out] samples Samples to fill. Vector should be pre-allocated, but
* values will be overwritten.
*/
void Siggen_genSignal(Siggen*,vd* samples);
/**
* Free Siggen data
*
* @param[in] Siggen* Signal generator private data
*/
void Siggen_free(Siggen*);
#endif //LASP_SIGGEN_H
//////////////////////////////////////////////////////////////////////