Improvement of Goertzel filter. Using Hamming window now. Add test routine.

src/test/Makefile.am

@@ -5,6 +5,7 @@ noinst_PROGRAMS = \
 	test_sendevolumenregler \
 	test_compandor \
 	test_emphasis \
+	test_goertzel \
 	test_dtmf \
 	test_dms \
 	test_sms \
@@ -150,3 +151,12 @@ test_v27scrambler_LDADD = \
 	$(top_builddir)/src/libv27/libv27.a \
 	-lm
 
+test_goertzel_SOURCES = test_goertzel.c dummy.c
+
+test_goertzel_LDADD = \
+	$(COMMON_LA) \
+	$(top_builddir)/src/libdebug/libdebug.a \
+	$(top_builddir)/src/libgoertzel/libgoertzel.a \
+	$(top_builddir)/src/liboptions/liboptions.a \
+	-lm
+

src/test/test_goertzel.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <math.h>
+#include <string.h>
+#include "../libsample/sample.h"
+#include "../libgoertzel/goertzel.h"
+#include "../libdebug/debug.h"
+
+#define level2db(level)		(20 * log10(level))
+#define db2level(db)		pow(10, (double)db / 20.0)
+
+#define SAMPLERATE	48000
+
+static void gen_samples(sample_t *samples, double freq)
+{
+	int i;
+	double value;
+
+	for (i = 0; i < SAMPLERATE; i++) {
+		value = cos(2.0 * M_PI * freq / (double)SAMPLERATE * (double)i);
+		samples[i] = value;
+	}
+}
+
+int num_kanal;
+
+int main(void)
+{
+	goertzel_t goertzel;
+	sample_t samples[SAMPLERATE];
+	double frequency = 1000;
+	double duration = 1.0/100.0;
+	double level;
+	double i;
+
+	printf("testing goertzel with frequency %.1f and duration 1 / %.0f\n", frequency, 1.0 / duration);
+
+	for (i = 700; i < 1301; i = i + 10) {
+		gen_samples(samples, (double)i);
+		audio_goertzel_init(&goertzel, frequency, SAMPLERATE);
+		audio_goertzel(&goertzel, samples, SAMPLERATE * duration, 0, &level, 1);
+		printf("%s%.0f Hz: %.1f dB", debug_db(level), i, level2db(level));
+		if ((int)round(i) == (int)round(frequency))
+			printf(" level=%.6f\n", level);
+		else
+			printf("\n");
+	}
+
+	return 0;
+}
+