fir_decimator.h

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/****************************************************************************
 * modules/include/digital_filter/fir_decimator.h
 *
 *   Copyright 2021 Sony Semiconductor Solutions Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of Sony Semiconductor Solutions Corporation nor
 *    the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef __INCLUDE_FILTERS_FIR_DECIMATOR_H
#define __INCLUDE_FILTERS_FIR_DECIMATOR_H
 
#include <nuttx/config.h>
 
#ifdef CONFIG_EXTERNALS_CMSIS_DSP
#include <arm_math.h>
 
typedef struct
{
  arm_fir_decimate_instance_f32 inst;
} decimator_instancef_t;
 
#else
#error "FIR filter needs CMSIS DSP library"
#endif
 
#  ifdef __cplusplus
#    define EXTERN extern "C"
extern "C"
{
#  else
#    define EXTERN extern
#  endif
 
/********************************************************************************
 * Public Function Prototypes
 ********************************************************************************/
 
decimator_instancef_t *create_decimatorf(int fs, int dec_factor,
    int tr_width, int blocksz);
 
decimator_instancef_t *create_decimatorf_tap(int fs, int dec_factor,
    int taps, int blocksz);
 
int decimator_executef(decimator_instancef_t *dec, float *input, int input_len,
    float *output, int output_len);
 
int decimator_tapnumf(decimator_instancef_t *dec);
 
void decimator_deletef(decimator_instancef_t *dec);
 
#  undef EXTERN
#  ifdef __cplusplus
}
#  endif
 
#endif  /* __INCLUDE_FILTERS_FIR_DECIMATOR_H */