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#ifndef _RMS_H
#define _RMS_H
#include <math.h>
#define RMS_BUF_SIZE 64
typedef struct {
float buffer[RMS_BUF_SIZE];
unsigned int pos;
float sum;
} rms_env;
rms_env *rms_env_new();
static inline float rms_env_process(rms_env *r, float x);
void rms_env_reset(rms_env *r);
void rms_env_free(rms_env *r);
inline static float rms_env_process(rms_env *r, const float x)
{
r->sum -= r->buffer[r->pos];
r->sum += x;
if (r->sum < 1.0e-6) {
r->sum = 0.0f;
}
r->buffer[r->pos] = x;
r->pos = (r->pos + 1) & (RMS_BUF_SIZE - 1);
return sqrt(r->sum / (float)RMS_BUF_SIZE);
}
#endif
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