dsps_ccorr_f32_ansi.c File Reference

#include "dsps_conv.h"
#include "esp_log.h"

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Functions
esp_err_t	dsps_ccorr_f32_ansi (const float *Signal, const int siglen, const float *Kernel, const int kernlen, float *corrvout)
	Cross correlation.

Variables
static const char *	TAG = "dsps_conv"

Function Documentation

dsps_ccorr_f32_ansi()

esp_err_t dsps_ccorr_f32_ansi	(	const float *	Signal,
		const int	siglen,
		const float *	Pattern,
		const int	patlen,
		float *	corrout )

Cross correlation.

The function make cross correlate between two ignals. The implementation use ANSI C and could be compiled and run on any platform

Parameters

[in]	Signal1	input array with input 1 signal values
[in]	siglen1	length of the input 1 signal array
[in]	Signal2	input array with input 2 signal values
[in]	siglen2	length of the input signal array
	corrout	output array with result of cross correlation. The size of dest array must be (siglen1 + siglen2 - 1) !!!

Returns

• ESP_OK on success
• One of the error codes from DSP library (one of the input array are NULL, or if (siglen < patlen))

Definition at line 20 of file dsps_ccorr_f32_ansi.c.

{
    if (NULL == Signal) {
        return ESP_ERR_DSP_PARAM_OUTOFRANGE;
    }
    if (NULL == Kernel) {
        return ESP_ERR_DSP_PARAM_OUTOFRANGE;
    }
    if (NULL == corrvout) {
        return ESP_ERR_DSP_PARAM_OUTOFRANGE;
    }
 
    float *sig = (float *)Signal;
    float *kern = (float *)Kernel;
    int lsig = siglen;
    int lkern = kernlen;
 
    if (siglen < kernlen) {
        sig = (float *)Kernel;
        kern = (float *)Signal;
        lsig = kernlen;
        lkern = siglen;
    }
 
    for (int n = 0; n < lkern; n++) {
        int k;
        int kmin = lkern - 1 - n;
        corrvout[n] = 0;
 
        for (k = 0; k <= n; k++) {
            corrvout[n] += sig[k] * kern[kmin + k];
        }
        ESP_LOGV(TAG, "L1 k = %i, n = %i , kmin= %i, kmax= %i", 0, n, kmin, kmin + n);
    }
    for (int n = lkern; n < lsig; n++) {
        int kmin, kmax, k;
 
        corrvout[n] = 0;
 
        kmin = n - lkern + 1;
        kmax = n;
        for (k = kmin; k <= kmax; k++) {
            corrvout[n] += sig[k] * kern[k - kmin];
        }
        ESP_LOGV(TAG, "L2 n=%i, kmin = %i, kmax = %i , k-kmin = %i", n, kmin, kmax, 0);
    }
 
    for (int n = lsig; n < lsig + lkern - 1; n++) {
        int kmin, kmax, k;
 
        corrvout[n] = 0;
 
        kmin = n - lkern + 1;
        kmax =  lsig - 1;
 
        for (k = kmin; k <= kmax; k++) {
            corrvout[n] += sig[k] * kern[k - kmin];
        }
        ESP_LOGV(TAG, "L3 n=%i, kmin = %i, kmax = %i , k - kmin = %i", n, kmin, kmax, kmax - kmin);
    }
    return ESP_OK;
}

References ESP_ERR_DSP_PARAM_OUTOFRANGE, ESP_OK, k, n, and TAG.

Variable Documentation

TAG

const char* TAG = "dsps_conv"

static

Definition at line 18 of file dsps_ccorr_f32_ansi.c.