From 88f174d0b8b749cf96a38e284f266d3bdaa55ef4 Mon Sep 17 00:00:00 2001
From: Ludovic Pouzenc <ludovic@pouzenc.fr>
Date: Sun, 10 Jun 2012 20:22:56 +0000
Subject: Bon, on reprends à plat les problèmes de maths avec des fichiers en
 entrée pour valider tutes les étapes...
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git-svn-id: file:///var/svn/2012-violon-leds/trunk@16 6be1fa4d-33ac-4c33-becc-79fcb3794bb6
---
 tests/test5/compute.c | 52 +++++++++++++++++++++++++++++----------------------
 1 file changed, 30 insertions(+), 22 deletions(-)

(limited to 'tests/test5/compute.c')

diff --git a/tests/test5/compute.c b/tests/test5/compute.c
index e8b03fc..d64f8c1 100644
--- a/tests/test5/compute.c
+++ b/tests/test5/compute.c
@@ -3,8 +3,9 @@
 #include "fft.h"
 #include <math.h>
 
+#define MIN_SAMPLES 256
 #define MAX_SAMPLES 2048
-static inline float todB_a(const float *x);
+//static inline float todB_a(const float *x);
 void compute_spectrum(float * data, int width, double rate, float *output);
 
 
@@ -13,42 +14,49 @@ gfloat compute_level(const float *data, size_t nsamples, size_t nchan) {
 	double rate=44100; //TODO dynamique
 	size_t i; 
 	float input[MAX_SAMPLES], output[128];
-	float level;
+	float value;
+	int gain=20, range=80;
 
 	if (nsamples >= MAX_SAMPLES) {
 		printf("WARN : nsamples >= MAX_SAMPLES : %i >= %i\n", nsamples, MAX_SAMPLES);
 		nsamples=MAX_SAMPLES;
 	}
-/* Just return the max peak
-	for (i=0;i<nsamples;i+=nchan) {
-		val=((float *)data)[i];
-		//printf("val==%i\n", val);
-		if (val<0) val=-val;
-		if (level<val) level=val;
+	if (nsamples < MIN_SAMPLES) {
+		printf("WARN : nsamples < MIN_SAMPLES : %i >= %i\n", nsamples, MIN_SAMPLES);
+		for (i=0;i<MIN_SAMPLES;i++) {
+			if ( (i/nsamples)%2==1 )
+				input[i]=data[i/**nchan*/];
+			else
+				input[i]=data[nsamples-i-1];
+		}
+		nsamples=MIN_SAMPLES;
+	} else {
+		for (i=0;i<nsamples;i++) {
+			input[i]=data[i/**nchan*/];
+		}
 	}
-*/
-	for (i=0;i<nsamples;i++) {
-		input[i]=data[i/**nchan*/];
-/*		printf("\r%f ", input[i]);
-		fflush(stdout);
-*/
-	}
-//	printf("\n");
 
 	compute_spectrum(input, nsamples, rate, output);
 	//printf("%f\n", output[0]);
-	level=0.f;
+	value=0.f;
 	for (i=1;i<128;i++) {
-		level+=output[i];
+		value+=output[i];
 	}
-	level/=127.f;
-	return level;
+	// Mean value
+	value/=127.f;
+	// 0.0 to 1.0 range
+	value=(value + gain + range) / (double)range;
+	value=MAX(0.f,value);
+	value=MIN(value,1.f);
+
+//	printf("DEBUG: nsamples=%8i value==%f\n", nsamples, value);
+	return value;
 }
-
+/*
 static inline float todB_a(const float *x){
   return (float)((*(int32_t *)x)&0x7fffffff) * 7.17711438e-7f -764.6161886f;
 }
-
+*/
 // Adapted from Audacity 
 void compute_spectrum(float * data, int width, double rate, float *output) {
 
-- 
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