Restructure: Move fm_modulation from common code to 'libfm'

5 files changed, 2 insertions, 424 deletions

diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index 52ee381..9e9908a 100644
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -7,7 +7,6 @@ libcommon_a_SOURCES = \
 	debug.c \
 	sound_alsa.c \
 	compandor.c \
-	fm_modulation.c \
 	fsk.c \
 	display_wave.c \
 	display_measurements.c
diff --git a/src/common/fm_modulation.c b/src/common/fm_modulation.c
deleted file mode 100644
index 93621c8..0000000
--- a/src/common/fm_modulation.c
+++ /dev/null
@@ -1,382 +0,0 @@
-/* FM modulation processing
- *
- * (C) 2017 by Andreas Eversberg <jolly@eversberg.eu>
- * All Rights Reserved
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
-#include <errno.h>
-#include <math.h>
-#include "sample.h"
-#include "fm_modulation.h"
-
-//#define FAST_SINE
-
-/* init FM modulator */
-int fm_mod_init(fm_mod_t *mod, double samplerate, double offset, double amplitude)
-{
-	int i;
-
-	memset(mod, 0, sizeof(*mod));
-	mod->samplerate = samplerate;
-	mod->offset = offset;
-	mod->amplitude = amplitude;
-
-	mod->ramp_length = samplerate * 0.001;
-	mod->ramp_tab = calloc(mod->ramp_length, sizeof(*mod->ramp_tab));
-	if (!mod->ramp_tab) {
-		fprintf(stderr, "No mem!\n");
-		return -ENOMEM;
-	}
-	mod->state = MOD_STATE_OFF;
-
-	/* generate ramp up with ramp_length */
-	for (i = 0; i < mod->ramp_length; i++)
-		mod->ramp_tab[i] = 0.5 - cos(M_PI * i / mod->ramp_length) / 2.0;
-
-#ifdef FAST_SINE
-	mod->sin_tab = calloc(65536+16384, sizeof(*mod->sin_tab));
-	if (!mod->sin_tab) {
-		fprintf(stderr, "No mem!\n");
-		fm_mod_exit(mod);
-		return -ENOMEM;
-	}
-
-	/* generate sine and cosine */
-	for (i = 0; i < 65536+16384; i++)
-		mod->sin_tab[i] = sin(2.0 * M_PI * (double)i / 65536.0) * amplitude;
-#endif
-
-	return 0;
-}
-
-void fm_mod_exit(fm_mod_t *mod)
-{
-	if (mod->ramp_tab) {
-		free(mod->ramp_tab);
-		mod->ramp_tab = NULL;
-	}
-	if (mod->sin_tab) {
-		free(mod->sin_tab);
-		mod->sin_tab = NULL;
-	}
-}
-
-/* do frequency modulation of samples and add them to existing baseband */
-void fm_modulate_complex(fm_mod_t *mod, sample_t *frequency, uint8_t *power, int length, float *baseband)
-{
-	double dev, rate, phase, offset;
-	int ramp, ramp_length;
-	double *ramp_tab;
-#ifdef FAST_SINE
-	double *sin_tab, *cos_tab;
-#else
-	double amplitude;
-#endif
-
-	rate = mod->samplerate;
-	phase = mod->phase;
-	offset = mod->offset;
-	ramp = mod->ramp;
-	ramp_length = mod->ramp_length;
-	ramp_tab = mod->ramp_tab;
-#ifdef FAST_SINE
-	sin_tab = mod->sin_tab;
-	cos_tab = mod->sin_tab + 16384;
-#else
-	amplitude = mod->amplitude;
-#endif
-
-again:
-	switch (mod->state) {
-	case MOD_STATE_ON:
-		/* modulate */
-		while (length) {
-			/* is power is not set, ramp down */
-			if (!(*power)) {
-				mod->state = MOD_STATE_RAMP_DOWN;
-				break;
-			}
-			/* deviation is defined by the frequency value and the offset */
-			dev = offset + *frequency++;
-			power++;
-			length--;
-#ifdef FAST_SINE
-			phase += 65536.0 * dev / rate;
-			if (phase < 0.0)
-				phase += 65536.0;
-			else if (phase >= 65536.0)
-				phase -= 65536.0;
-			*baseband++ += cos_tab[(uint16_t)phase];
-			*baseband++ += sin_tab[(uint16_t)phase];
-#else
-			phase += 2.0 * M_PI * dev / rate;
-			if (phase < 0.0)
-				phase += 2.0 * M_PI;
-			else if (phase >= 2.0 * M_PI)
-				phase -= 2.0 * M_PI;
-			*baseband++ += cos(phase) * amplitude;
-			*baseband++ += sin(phase) * amplitude;
-#endif
-		}
-		break;
-	case MOD_STATE_RAMP_DOWN:
-		while (length) {
-			/* if power is set, ramp up */
-			if (*power) {
-				mod->state = MOD_STATE_RAMP_UP;
-				break;
-			}
-			if (ramp == 0) {
-				mod->state = MOD_STATE_OFF;
-				break;
-			}
-			dev = offset + *frequency++;
-			power++;
-			length--;
-#ifdef FAST_SINE
-			phase += 65536.0 * dev / rate;
-			if (phase < 0.0)
-				phase += 65536.0;
-			else if (phase >= 65536.0)
-				phase -= 65536.0;
-			*baseband++ += cos_tab[(uint16_t)phase] * ramp_tab[ramp];
-			*baseband++ += sin_tab[(uint16_t)phase] * ramp_tab[ramp];
-#else
-			phase += 2.0 * M_PI * dev / rate;
-			if (phase < 0.0)
-				phase += 2.0 * M_PI;
-			else if (phase >= 2.0 * M_PI)
-				phase -= 2.0 * M_PI;
-			*baseband++ += cos(phase) * amplitude * ramp_tab[ramp];
-			*baseband++ += sin(phase) * amplitude * ramp_tab[ramp];
-#endif
-			ramp--;
-		}
-		break;
-	case MOD_STATE_OFF:
-		while (length) {
-			/* if power is set, ramp up */
-			if (*power) {
-				mod->state = MOD_STATE_RAMP_UP;
-				break;
-			}
-			frequency++;
-			power++;
-			length--;
-			baseband += 2;
-		}
-		break;
-	case MOD_STATE_RAMP_UP:
-		while (length) {
-			/* is power is not set, ramp down */
-			if (!(*power)) {
-				mod->state = MOD_STATE_RAMP_DOWN;
-				break;
-			}
-			if (ramp == ramp_length - 1) {
-				mod->state = MOD_STATE_ON;
-				break;
-			}
-			/* deviation is defined by the frequency value and the offset */
-			dev = offset + *frequency++;
-			power++;
-			length--;
-#ifdef FAST_SINE
-			phase += 65536.0 * dev / rate;
-			if (phase < 0.0)
-				phase += 65536.0;
-			else if (phase >= 65536.0)
-				phase -= 65536.0;
-			*baseband++ += cos_tab[(uint16_t)phase] * ramp_tab[ramp];
-			*baseband++ += sin_tab[(uint16_t)phase] * ramp_tab[ramp];
-#else
-			phase += 2.0 * M_PI * dev / rate;
-			if (phase < 0.0)
-				phase += 2.0 * M_PI;
-			else if (phase >= 2.0 * M_PI)
-				phase -= 2.0 * M_PI;
-			*baseband++ += cos(phase) * amplitude * ramp_tab[ramp];
-			*baseband++ += sin(phase) * amplitude * ramp_tab[ramp];
-#endif
-			ramp++;
-		}
-		break;
-	}
-	if (length)
-		goto again;
-
-	mod->phase = phase;
-	mod->ramp = ramp;
-}
-
-/* init FM demodulator */
-int fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth)
-{
-	memset(demod, 0, sizeof(*demod));
-	demod->samplerate = samplerate;
-#ifdef FAST_SINE
-	demod->rot = 65536.0 * -offset / samplerate;
-#else
-	demod->rot = 2 * M_PI * -offset / samplerate;
-#endif
-
-	/* use fourth order (2 iter) filter, since it is as fast as second order (1 iter) filter */
-	iir_lowpass_init(&demod->lp[0], bandwidth / 2.0, samplerate, 2);
-	iir_lowpass_init(&demod->lp[1], bandwidth / 2.0, samplerate, 2);
-
-#ifdef FAST_SINE
-	int i;
-
-	demod->sin_tab = calloc(65536+16384, sizeof(*demod->sin_tab));
-	if (!demod->sin_tab) {
-		fprintf(stderr, "No mem!\n");
-		return -ENOMEM;
-	}
-
-	/* generate sine and cosine */
-	for (i = 0; i < 65536+16384; i++)
-		demod->sin_tab[i] = sin(2.0 * M_PI * (double)i / 65536.0);
-#endif
-
-	return 0;
-}
-
-void fm_demod_exit(fm_demod_t *demod)
-{
-	if (demod->sin_tab) {
-		free(demod->sin_tab);
-		demod->sin_tab = NULL;
-	}
-}
-
-/* do frequency demodulation of baseband and write them to samples */
-void fm_demodulate_complex(fm_demod_t *demod, sample_t *frequency, int length, float *baseband, sample_t *I, sample_t *Q)
-{
-	double phase, rot, last_phase, dev, rate;
-	double _sin, _cos;
-	sample_t i, q;
-	int s, ss;
-#ifdef FAST_SINE
-	double *sin_tab, *cos_tab;
-#endif
-
-	rate = demod->samplerate;
-	phase = demod->phase;
-	rot = demod->rot;
-#ifdef FAST_SINE
-	sin_tab = demod->sin_tab;
-	cos_tab = demod->sin_tab + 16384;
-#endif
-	for (s = 0, ss = 0; s < length; s++) {
-		phase += rot;
-		i = baseband[ss++];
-		q = baseband[ss++];
-#ifdef FAST_SINE
-		if (phase < 0.0)
-			phase += 65536.0;
-		else if (phase >= 65536.0)
-			phase -= 65536.0;
-		_sin = sin_tab[(uint16_t)phase];
-		_cos = cos_tab[(uint16_t)phase];
-#else
-		if (phase < 0.0)
-			phase += 2.0 * M_PI;
-		else if (phase >= 2.0 * M_PI)
-			phase -= 2.0 * M_PI;
-		_sin = sin(phase);
-		_cos = cos(phase);
-#endif
-		I[s] = i * _cos - q * _sin;
-		Q[s] = i * _sin + q * _cos;
-	}
-	demod->phase = phase;
-	iir_process(&demod->lp[0], I, length);
-	iir_process(&demod->lp[1], Q, length);
-	last_phase = demod->last_phase;
-	for (s = 0; s < length; s++) {
-		phase = atan2(Q[s], I[s]);
-		dev = (phase - last_phase) / 2 / M_PI;
-		last_phase = phase;
-		if (dev < -0.49)
-			dev += 1.0;
-		else if (dev > 0.49)
-			dev -= 1.0;
-		dev *= rate;
-		frequency[s] = dev;
-	}
-	demod->last_phase = last_phase;
-}
-
-void fm_demodulate_real(fm_demod_t *demod, sample_t *frequency, int length, sample_t *baseband, sample_t *I, sample_t *Q)
-{
-	double phase, rot, last_phase, dev, rate;
-	double _sin, _cos;
-	sample_t i;
-	int s, ss;
-#ifdef FAST_SINE
-	double *sin_tab, *cos_tab;
-#endif
-
-	rate = demod->samplerate;
-	phase = demod->phase;
-	rot = demod->rot;
-#ifdef FAST_SINE
-	sin_tab = demod->sin_tab;
-	cos_tab = demod->sin_tab + 16384;
-#endif
-	for (s = 0, ss = 0; s < length; s++) {
-		phase += rot;
-		i = baseband[ss++];
-#ifdef FAST_SINE
-		if (phase < 0.0)
-			phase += 65536.0;
-		else if (phase >= 65536.0)
-			phase -= 65536.0;
-		_sin = sin_tab[(uint16_t)phase];
-		_cos = cos_tab[(uint16_t)phase];
-#else
-		if (phase < 0.0)
-			phase += 2.0 * M_PI;
-		else if (phase >= 2.0 * M_PI)
-			phase -= 2.0 * M_PI;
-		_sin = sin(phase);
-		_cos = cos(phase);
-#endif
-		I[s] = i * _cos;
-		Q[s] = i * _sin;
-	}
-	demod->phase = phase;
-	iir_process(&demod->lp[0], I, length);
-	iir_process(&demod->lp[1], Q, length);
-	last_phase = demod->last_phase;
-	for (s = 0; s < length; s++) {
-		phase = atan2(Q[s], I[s]);
-		dev = (phase - last_phase) / 2 / M_PI;
-		last_phase = phase;
-		if (dev < -0.49)
-			dev += 1.0;
-		else if (dev > 0.49)
-			dev -= 1.0;
-		dev *= rate;
-		frequency[s] = dev;
-	}
-	demod->last_phase = last_phase;
-}
-
diff --git a/src/common/fm_modulation.h b/src/common/fm_modulation.h
deleted file mode 100644
index 68f0bcd..0000000
--- a/src/common/fm_modulation.h
+++ /dev/null
@@ -1,39 +0,0 @@
-#include "../libfilter/iir_filter.h"
-
-enum fm_mod_state {
-	MOD_STATE_OFF,		/* transmitter off, no IQ vector */
-	MOD_STATE_ON,		/* transmitter on, FM modulated IQ vector */
-	MOD_STATE_RAMP_UP,	/* use half cos to ramp up IQ vector */
-	MOD_STATE_RAMP_DOWN,	/* use half cos to ramp down IQ vector */
-};
-
-typedef struct fm_mod {
-	double samplerate;	/* sample rate of in and out */
-	double offset;		/* offset to calculated center frequency */
-	double amplitude;	/* how much amplitude to add to the buff */
-	double phase;		/* current phase of FM (used to shift and modulate ) */
-	double *sin_tab;	/* sine/cosine table for modulation */
-	enum fm_mod_state state;/* state of transmit power */
-	double *ramp_tab;	/* half cosine ramp up */
-	int ramp;		/* current ramp position */
-	int ramp_length;	/* number of values in ramp */
-} fm_mod_t;
-
-int fm_mod_init(fm_mod_t *mod, double samplerate, double offset, double amplitude);
-void fm_mod_exit(fm_mod_t *mod);
-void fm_modulate_complex(fm_mod_t *mod, sample_t *frequency, uint8_t *power, int num, float *baseband);
-
-typedef struct fm_demod {
-	double samplerate;	/* sample rate of in and out */
-	double phase;		/* current rotation phase (used to shift) */
-	double rot;		/* rotation step per sample to shift rx frequency (used to shift) */
-	double last_phase;	/* last phase of FM (used to demodulate) */
-	iir_filter_t lp[2];	/* filters received IQ signal */
-	double *sin_tab;	/* sine/cosine table rotation */
-} fm_demod_t;
-
-int fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth);
-void fm_demod_exit(fm_demod_t *demod);
-void fm_demodulate_complex(fm_demod_t *demod, sample_t *frequency, int length, float *baseband, sample_t *I, sample_t *Q);
-void fm_demodulate_real(fm_demod_t *demod, sample_t *frequency, int length, sample_t *baseband, sample_t *I, sample_t *Q);
-
diff --git a/src/common/fsk.h b/src/common/fsk.h
index 723fe66..a7cc428 100644
--- a/src/common/fsk.h
+++ b/src/common/fsk.h
@@ -1,4 +1,4 @@
-#include "../common/fm_modulation.h"
+#include "../libfm/fm.h"
 
 typedef struct ffsk {
 	void		*inst;
diff --git a/src/common/sdr.c b/src/common/sdr.c
index 01048ee..d7a445b 100644
--- a/src/common/sdr.c
+++ b/src/common/sdr.c
@@ -30,7 +30,7 @@ enum paging_signal;
 #include <pthread.h>
 #include <unistd.h>
 #include "sample.h"
-#include "fm_modulation.h"
+#include "../libfm/fm.h"
 #include "../libtimer/timer.h"
 #include "sender.h"
 #include "sdr_config.h"