Restructure: Move sample from common code to 'libsample'

libcompandor/compandor.c

@@ -21,7 +21,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "compandor.h"
 
 //#define db2level(db)			pow(10, (double)db / 20.0)

libdtmf/dtmf_encode.c

@@ -20,7 +20,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "dtmf_encode.h"
 
 #define PI		M_PI

libemphasis/emphasis.c

@@ -21,7 +21,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "../libfilter/iir_filter.h"
 #include "emphasis.h"

libfilter/iir_filter.c

@@ -22,7 +22,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "iir_filter.h"
 
 #define PI M_PI

libfm/fm.c

@@ -23,7 +23,7 @@
 #include <string.h>
 #include <errno.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "fm.h"
 
 //#define FAST_SINE

libfsk/fsk.c

@@ -23,7 +23,7 @@
 #include <string.h>
 #include <errno.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "fsk.h"
 

libgoertzel/goertzel.c

@@ -22,7 +22,7 @@
 #include <string.h>
 #include <errno.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "goertzel.h"
 

libjitter/jitter.c

@@ -22,7 +22,7 @@
 #include <string.h>
 #include <errno.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "jitter.h"
 

libmncc/mncc_console.c

@@ -24,7 +24,7 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <sys/time.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../libsamplerate/samplerate.h"
 #include "../libjitter/jitter.h"
 #include "../common/debug.h"

libmncc/mncc_cross.c

@@ -22,7 +22,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "../common/call.h"
 #include "cause.h"

libmncc/mncc_sock.c

@@ -26,7 +26,7 @@
 #include <sys/un.h>
 #include <stddef.h>
 #include <unistd.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "../common/call.h"
 #include "cause.h"

libsample/Makefile.am

@@ -0,0 +1,6 @@
+AM_CPPFLAGS = -Wall -Wextra -g $(all_includes)
+
+noinst_LIBRARIES = libsample.a
+
+libsample_a_SOURCES = \
+	sample.c

libsample/sample.c

@@ -0,0 +1,64 @@
+/* Sample definition
+ *
+ * (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 <stdint.h>
+#include "sample.h"
+
+/*
+ * A regular voice conversation takes place at this factor below the full range
+ * of 16 bits signed value:
+ */
+static double int_16_speech_level = SPEECH_LEVEL * 0.7079; /* 16 dBm below dBm0, which is about 3dBm below full 16 bit range */
+
+/* A sample_t is a value that has virtually infinite precision but will also
+ * support high numbers. 'double' or 'float' types are sufficient.
+ *
+ * When using sample_t inside signal processing of each base station, the
+ * level of +- 1 is relative to the normal speach evenlope.
+ *
+ * When converting sample_t to int16_t, the level of +- 1 is reduced by factor.
+ * This way the speech may be louder before clipping happens.
+ *
+ * When using sample_t to modulate (SDR or sound card), the level is changed,
+ * so it represents the frequency deviation in Hz. The deviation of speech
+ * envelope is network dependant.
+ */
+
+void samples_to_int16(int16_t *spl, sample_t *samples, int length)
+{
+	int32_t value;
+
+	while (length--) {
+		value = *samples++ * int_16_speech_level * 32768.0;
+		if (value > 32767.0)
+			*spl++ = 32767;
+		else if (value < -32767.0)
+			*spl++ = -32767;
+		else
+			*spl++ = (uint16_t)value;
+	}
+}
+
+void int16_to_samples(sample_t *samples, int16_t *spl, int length)
+{
+	while (length--) {
+		*samples++ = (double)(*spl++) / 32767.0 / int_16_speech_level;
+	}
+}
+

libsample/sample.h

@@ -0,0 +1,8 @@
+
+typedef double sample_t;
+
+#define	SPEECH_LEVEL	0.1585
+
+void samples_to_int16(int16_t *spl, sample_t *samples, int length);
+void int16_to_samples(sample_t *samples, int16_t *spl, int length);
+

libsamplerate/samplerate.c

@@ -22,7 +22,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "samplerate.h"
 
 int init_samplerate(samplerate_t *state, double low_samplerate, double high_samplerate, double filter_cutoff)

libscrambler/scrambler.c

@@ -19,7 +19,7 @@
 
 #include <stdint.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "scrambler.h"
 
 #define PI		M_PI

libsdr/display_iq.c

@@ -23,7 +23,7 @@
 #include <math.h>
 #include <pthread.h>
 #include <stdlib.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/sender.h"
 
 /* must be odd value! */

libsdr/display_spectrum.c

@@ -22,7 +22,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/sender.h"
 #include "../libfft/fft.h"
 

libsdr/sdr.c

@@ -29,7 +29,7 @@ enum paging_signal;
 #define __USE_GNU
 #include <pthread.h>
 #include <unistd.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../libfm/fm.h"
 #include "../libtimer/timer.h"
 #include "../common/sender.h"

libsdr/sdr_config.c

@@ -24,7 +24,7 @@ enum paging_signal;
 #include <string.h>
 #include <stdint.h>
 #include <getopt.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "sdr.h"
 #include "sdr_config.h"
 

libsound/sound_alsa.c

@@ -21,7 +21,7 @@
 #include <stdint.h>
 #include <math.h>
 #include <alsa/asoundlib.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "../common/debug.h"
 #include "../common/sender.h"
 

libwave/wave.c

@@ -24,7 +24,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <pthread.h>
-#include "../common/sample.h"
+#include "../libsample/sample.h"
 #include "wave.h"
 
 /* NOTE: No locking required for writing and reading buffer pointers, since 'int' is atomic on >=32 bit machines */