alsabat: add noise detection

index 58781d6..bdb1f83 100644
@@ -26,10 +26,11 @@
 #include "gettext.h"
 
 #include "common.h"
+#include "bat-signal.h"
 
-static void check_amplitude(struct bat *bat, double *buf)
+static void check_amplitude(struct bat *bat, float *buf)
 {
-	double sum, average, amplitude;
+	float sum, average, amplitude;
 	int i, percent;
 
 	/* calculate average value */

@@ -39,7 +40,7 @@ static void check_amplitude(struct bat *bat, double *buf)
 
 	/* calculate peak-to-average amplitude */
 	for (i = 0, sum = 0.0; i < bat->frames; i++)
-		sum += abs(buf[i] - average);
+		sum += fabsf(buf[i] - average);
 	amplitude = sum / bat->frames * M_PI / 2.0;
 
 	/* calculate amplitude percentage against full range */

@@ -71,9 +72,9 @@ int check_peak(struct bat *bat, struct analyze *a, int end, int peak, float hz,
 	float tolerance = (delta_rate > delta_HZ) ? delta_rate : delta_HZ;
 
 	fprintf(bat->log, _("Detected peak at %2.2f Hz of %2.2f dB\n"), hz_peak,
-			10.0 * log10(a->mag[peak] / mean));
+			10.0 * log10f(a->mag[peak] / mean));
 	fprintf(bat->log, _(" Total %3.1f dB from %2.2f to %2.2f Hz\n"),
-			10.0 * log10(p / mean), start * hz, end * hz);
+			10.0 * log10f(p / mean), start * hz, end * hz);
 
 	if (hz_peak < DC_THRESHOLD) {
 		fprintf(bat->err, _(" WARNING: Found low peak %2.2f Hz,"),

@@ -161,7 +162,7 @@ static int check(struct bat *bat, struct analyze *a, int channel)
 
 static void calc_magnitude(struct bat *bat, struct analyze *a, int N)
 {
-	double r2, i2;
+	float r2, i2;
 	int i;
 
 	for (i = 1; i < N / 2; i++) {

@@ -176,36 +177,36 @@ static void calc_magnitude(struct bat *bat, struct analyze *a, int N)
 static int find_and_check_harmonics(struct bat *bat, struct analyze *a,
 		int channel)
 {
-	fftw_plan p;
+	fftwf_plan p;
 	int err = -ENOMEM, N = bat->frames;
 
 	/* Allocate FFT buffers */
-	a->in = (double *) fftw_malloc(sizeof(double) * bat->frames);
+	a->in = (float *) fftwf_malloc(sizeof(float) * bat->frames);
 	if (a->in == NULL)
 		goto out1;
 
-	a->out = (double *) fftw_malloc(sizeof(double) * bat->frames);
+	a->out = (float *) fftwf_malloc(sizeof(float) * bat->frames);
 	if (a->out == NULL)
 		goto out2;
 
-	a->mag = (double *) fftw_malloc(sizeof(double) * bat->frames);
+	a->mag = (float *) fftwf_malloc(sizeof(float) * bat->frames);
 	if (a->mag == NULL)
 		goto out3;
 
 	/* create FFT plan */
-	p = fftw_plan_r2r_1d(N, a->in, a->out, FFTW_R2HC,
+	p = fftwf_plan_r2r_1d(N, a->in, a->out, FFTW_R2HC,
 			FFTW_MEASURE | FFTW_PRESERVE_INPUT);
 	if (p == NULL)
 		goto out4;
 
-	/* convert source PCM to doubles */
-	bat->convert_sample_to_double(a->buf, a->in, bat->frames);
+	/* convert source PCM to floats */
+	bat->convert_sample_to_float(a->buf, a->in, bat->frames);
 
 	/* check amplitude */
 	check_amplitude(bat, a->in);
 
 	/* run FFT */
-	fftw_execute(p);
+	fftwf_execute(p);
 
 	/* FFT out is real and imaginary numbers - calc magnitude for each */
 	calc_magnitude(bat, a, N);

@@ -213,14 +214,14 @@ static int find_and_check_harmonics(struct bat *bat, struct analyze *a,
 	/* check data */
 	err = check(bat, a, channel);
 
-	fftw_destroy_plan(p);
+	fftwf_destroy_plan(p);
 
 out4:
-	fftw_free(a->mag);
+	fftwf_free(a->mag);
 out3:
-	fftw_free(a->out);
+	fftwf_free(a->out);
 out2:
-	fftw_free(a->in);
+	fftwf_free(a->in);
 out1:
 	return err;
 }

index cd4ea2d..d534d48 100644
@@ -37,7 +37,7 @@
 #include "alsa.h"
 #endif
 #include "convert.h"
-#ifdef HAVE_LIBFFTW3
+#ifdef HAVE_LIBFFTW3F
 #include "analyze.h"
 #endif
 

@@ -67,7 +67,7 @@ static int get_duration(struct bat *bat)
 
 	if (bat->frames <= 0 || bat->frames > MAX_FRAMES) {
 		fprintf(bat->err, _("Invalid duration. Range: (0, %d(%fs))\n"),
-				MAX_FRAMES, (double)MAX_FRAMES / bat->rate);
+				MAX_FRAMES, (float)MAX_FRAMES / bat->rate);
 		return -EINVAL;
 	}
 

@@ -317,7 +317,7 @@ static void set_defaults(struct bat *bat)
 	bat->sample_size = 2;
 	bat->format = BAT_PCM_FORMAT_S16_LE;
 	bat->convert_float_to_sample = convert_float_to_int16;
-	bat->convert_sample_to_double = convert_int16_to_double;
+	bat->convert_sample_to_float = convert_int16_to_float;
 	bat->frames = bat->rate * 2;
 	bat->target_freq[0] = 997.0;
 	bat->target_freq[1] = 997.0;

@@ -569,19 +569,19 @@ static int bat_init(struct bat *bat)
 	switch (bat->sample_size) {
 	case 1:
 		bat->convert_float_to_sample = convert_float_to_uint8;
-		bat->convert_sample_to_double = convert_uint8_to_double;
+		bat->convert_sample_to_float = convert_uint8_to_float;
 		break;
 	case 2:
 		bat->convert_float_to_sample = convert_float_to_int16;
-		bat->convert_sample_to_double = convert_int16_to_double;
+		bat->convert_sample_to_float = convert_int16_to_float;
 		break;
 	case 3:
 		bat->convert_float_to_sample = convert_float_to_int24;
-		bat->convert_sample_to_double = convert_int24_to_double;
+		bat->convert_sample_to_float = convert_int24_to_float;
 		break;
 	case 4:
 		bat->convert_float_to_sample = convert_float_to_int32;
-		bat->convert_sample_to_double = convert_int32_to_double;
+		bat->convert_sample_to_float = convert_int32_to_float;
 		break;
 	default:
 		fprintf(bat->err, _("Invalid PCM format: size=%d\n"),

@@ -633,7 +633,7 @@ int main(int argc, char *argv[])
 		test_loopback(&bat);
 
 analyze:
-#ifdef HAVE_LIBFFTW3
+#ifdef HAVE_LIBFFTW3F
 	if (!bat.standalone)
 		err = analyze_capture(&bat);
 #else

index ad02a5a..ad91270 100644
@@ -182,7 +182,7 @@ struct bat {
 	FILE *log;
 	FILE *err;
 
-	void (*convert_sample_to_double)(void *, double *, int);
+	void (*convert_sample_to_float)(void *, float *, int);
 	void (*convert_float_to_sample)(float *, void *, int, int);
 
 	void *buf;			/* PCM Buffer */

@@ -192,9 +192,9 @@ struct bat {
 
 struct analyze {
 	void *buf;
-	double *in;
-	double *out;
-	double *mag;
+	float *in;
+	float *out;
+	float *mag;
 };
 
 void prepare_wav_info(struct wav_container *, struct bat *);

index dcbe912..f555389 100644
@@ -18,7 +18,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 
-void convert_uint8_to_double(void *buf, double *val, int samples)
+void convert_uint8_to_float(void *buf, float *val, int samples)
 {
 	int i;
 

@@ -26,7 +26,7 @@ void convert_uint8_to_double(void *buf, double *val, int samples)
 		val[i] = ((uint8_t *) buf)[i];
 }
 
-void convert_int16_to_double(void *buf, double *val, int samples)
+void convert_int16_to_float(void *buf, float *val, int samples)
 {
 	int i;
 

@@ -34,7 +34,7 @@ void convert_int16_to_double(void *buf, double *val, int samples)
 		val[i] = ((int16_t *) buf)[i];
 }
 
-void convert_int24_to_double(void *buf, double *val, int samples)
+void convert_int24_to_float(void *buf, float *val, int samples)
 {
 	int i;
 	int32_t tmp;

@@ -48,7 +48,7 @@ void convert_int24_to_double(void *buf, double *val, int samples)
 	}
 }
 
-void convert_int32_to_double(void *buf, double *val, int samples)
+void convert_int32_to_float(void *buf, float *val, int samples)
 {
 	int i;
 

index 28828ba..699c07a 100644
@@ -13,10 +13,10 @@
  *
  */
 
-void convert_uint8_to_double(void *, double *, int);
-void convert_int16_to_double(void *, double *, int);
-void convert_int24_to_double(void *, double *, int);
-void convert_int32_to_double(void *, double *, int);
+void convert_uint8_to_float(void *, float *, int);
+void convert_int16_to_float(void *, float *, int);
+void convert_int24_to_float(void *, float *, int);
+void convert_int32_to_float(void *, float *, int);
 void convert_float_to_uint8(float *, void *, int, int);
 void convert_float_to_int16(float *, void *, int, int);
 void convert_float_to_int24(float *, void *, int, int);

index 61d2824..15bea0a 100644
@@ -75,7 +75,7 @@ float sin_generator_next_sample(struct sin_generator *sg)
 	sg->state_real = sr * pr - si * pi;
 	sg->state_imag = sr * pi + pr * si;
 	/* return the input value so sine wave starts at exactly 0.0 */
-	return sr;
+	return (float)sr;
 }
 
 /* fills a vector with a sine wave */

index a295517..3c314a5 100644
@@ -28,3 +28,4 @@ int sin_generator_init(struct sin_generator *, float, float, float);
 float sin_generator_next_sample(struct sin_generator *);
 void sin_generator_vfill(struct sin_generator *, float *, int);
 int generate_sine_wave(struct bat *, int, void *);
+int generate_sine_wave_raw_mono(struct bat *, float *, float, int);

index 2047f53..c9b5c7b 100644
@@ -183,3 +183,21 @@ exit:
 
 	return err;
 }
+
+/* generate single channel sine waveform without sample conversion */
+int generate_sine_wave_raw_mono(struct bat *bat, float *buf,
+		float freq, int nsamples)
+{
+	int err = 0;
+	struct sin_generator sg;
+
+	err = sin_generator_init(&sg, 1.0, freq, bat->rate);
+	if (err < 0)
+		return err;
+	sin_generator_vfill(&sg, buf, nsamples);
+
+	/* adjust amplitude and offset of waveform */
+	err = adjust_waveform(bat, buf, nsamples, 1);
+
+	return err;
+}

index 15bea0a..2047f53 100644
@@ -109,7 +109,8 @@ static int reorder(struct bat *bat, float *val, int frames)
 	return 0;
 }
 
-static int adjust_waveform(struct bat *bat, float *val, int frames)
+static int adjust_waveform(struct bat *bat, float *val, int frames,
+		int channels)
 {
 	int i, nsamples, max;
 	float factor, offset = 0.0;

@@ -134,7 +135,7 @@ static int adjust_waveform(struct bat *bat, float *val, int frames)
 	}
 
 	factor = max * RANGE_FACTOR;
-	nsamples = bat->channels * frames;
+	nsamples = channels * frames;
 
 	for (i = 0; i < nsamples; i++)
 		val[i] = val[i] * factor + offset;

@@ -171,7 +172,7 @@ int generate_sine_wave(struct bat *bat, int frames, void *buf)
 		goto exit;
 
 	/* adjust amplitude and offset of waveform */
-	err = adjust_waveform(bat, sinus_f, frames);
+	err = adjust_waveform(bat, sinus_f, frames, bat->channels);
 	if (err != 0)
 		goto exit;
 

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88 lines not on this page · raw message

index ad91270..8214a03 100644
@@ -22,6 +22,8 @@
 #define OPT_SAVEPLAY			(OPT_BASE + 3)
 #define OPT_LOCAL			(OPT_BASE + 4)
 #define OPT_STANDALONE			(OPT_BASE + 5)
+#define OPT_SNRTHD_DB			(OPT_BASE + 7)
+#define OPT_SNRTHD_PC			(OPT_BASE + 8)
 
 #define COMPOSE(a, b, c, d)		((a) | ((b)<<8) | ((c)<<16) | ((d)<<24))
 #define WAV_RIFF			COMPOSE('R', 'I', 'F', 'F')

@@ -75,6 +77,23 @@
 #define SHIFT_MAX			(sizeof(int) * 8 - 2)
 #define SHIFT_MIN			8
 
+/* Define SNR range in dB.
+ * if the noise is equal to signal, SNR = 0.0dB;
+ * if the noise is zero, SNR is limited by RIFF wav data width:
+ *     8 bit  -->  20.0 * log10f (powf(2.0, 8.0))  = 48.16 dB
+ *    16 bit  -->  20.0 * log10f (powf(2.0, 16.0)) = 96.33 dB
+ *    24 bit  -->  20.0 * log10f (powf(2.0, 24.0)) = 144.49 dB
+ *    32 bit  -->  20.0 * log10f (powf(2.0, 32.0)) = 192.66 dB
+ * so define the SNR range (0.0, 200.0) dB, value out of range is invalid. */
+#define SNR_DB_INVALID			-1.0
+#define SNR_DB_MIN			0.0
+#define SNR_DB_MAX			200.0
+
+inline bool snr_is_valid(float db)
+{
+	return (db > SNR_DB_MIN && db < SNR_DB_MAX);
+}
+
 struct wav_header {
 	unsigned int magic; /* 'RIFF' */
 	unsigned int length; /* file len */

@@ -151,6 +170,14 @@ struct sin_generator {
 	float magnitude;
 };
 
+struct noise_analyzer {
+	int nsamples;			/* number of sample */
+	float *source;			/* single-tone to be analyzed */
+	float *target;			/* target single-tone as standard */
+	float rms_tgt;			/* rms of target single-tone */
+	float snr_db;			/* snr in dB */
+};
+
 struct bat {
 	unsigned int rate;		/* sampling rate */
 	int channels;			/* nb of channels */

@@ -162,6 +189,7 @@ struct bat {
 	int period_size;		/* period size in frames */
 
 	float sigma_k;			/* threshold for peak detection */
+	float snr_thd_db;		/* threshold for noise detection (dB) */
 	float target_freq[MAX_CHANNELS];
 
 	int sinus_duration;		/* number of frames for playback */