From e42911405c4bc2f8c097f47d4598baf8522ef3da Mon Sep 17 00:00:00 2001
From: FreeArtMan <dos21h@gmail.com>
Date: Sun, 8 May 2016 16:02:01 +0100
Subject: Moved source to src directory

---
 src/filt/Kconfig      |  0
 src/filt/filt.h       | 16 ++++++++++++++++
 src/filt/filt_5th.c   | 32 ++++++++++++++++++++++++++++++++
 src/filt/filt_delay.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/filt/make.mk      | 11 +++++++++++
 5 files changed, 110 insertions(+)
 create mode 100644 src/filt/Kconfig
 create mode 100644 src/filt/filt.h
 create mode 100644 src/filt/filt_5th.c
 create mode 100644 src/filt/filt_delay.c
 create mode 100644 src/filt/make.mk

(limited to 'src/filt')

diff --git a/src/filt/Kconfig b/src/filt/Kconfig
new file mode 100644
index 0000000..e69de29
diff --git a/src/filt/filt.h b/src/filt/filt.h
new file mode 100644
index 0000000..9ce2caa
--- /dev/null
+++ b/src/filt/filt.h
@@ -0,0 +1,16 @@
+#ifndef __RADIOLA_FILT_H
+#define __RADIOLA_FILT_H
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+//fifth order filter from rtlsdr
+void filt_5th(int16_t *data, int length, int16_t *hist);
+
+//delay filtering from https://github.com/dpiponi/mini_fm.git
+void filt_delay( uint8_t *buf, int buf_len );
+
+#endif
\ No newline at end of file
diff --git a/src/filt/filt_5th.c b/src/filt/filt_5th.c
new file mode 100644
index 0000000..23d5aab
--- /dev/null
+++ b/src/filt/filt_5th.c
@@ -0,0 +1,32 @@
+#include "filt.h"
+
+void f_5th(int16_t *data, int length, int16_t *hist)
+/* for half of interleaved data */
+{
+	int i;
+	int16_t a, b, c, d, e, f;
+	a = hist[1];
+	b = hist[2];
+	c = hist[3];
+	d = hist[4];
+	e = hist[5];
+	f = data[0];
+	/* a downsample should improve resolution, so don't fully shift */
+	data[0] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	for (i=4; i<length; i+=4) {
+		a = c;
+		b = d;
+		c = e;
+		d = f;
+		e = data[i-2];
+		f = data[i];
+		data[i/2] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	}
+	/* archive */
+	hist[0] = a;
+	hist[1] = b;
+	hist[2] = c;
+	hist[3] = d;
+	hist[4] = e;
+	hist[5] = f;
+}
diff --git a/src/filt/filt_delay.c b/src/filt/filt_delay.c
new file mode 100644
index 0000000..53da0b0
--- /dev/null
+++ b/src/filt/filt_delay.c
@@ -0,0 +1,51 @@
+#include "filt.h"
+
+//delay filtering
+void filt_delay( uint8_t *buf, int buf_len )
+{
+	//delay length
+	const int n=10;
+	
+	int i=0;
+	uint32_t cycle=0;
+	uint32_t avg_i=0, avg_q=0;
+	uint32_t cyc_buffer_i[n],delay_i=0;
+	uint32_t cyc_buffer_q[n],delay_q=0;
+	uint8_t in1=0,in2=0,out1=0,out2=0;
+
+	memset( cyc_buffer_i, 0, n*sizeof(uint32_t) );
+	memset( cyc_buffer_q, 0, n*sizeof(uint32_t) );
+
+	//for (i=0; i<(buf_len-(n*2));i+=2)
+	for (i=0 ; i<(buf_len-1) ; i+=2 )
+	//for (i=0; i<1000; i+=2)
+	{
+		in1 = buf[i];
+		in2 = buf[i+1];
+
+		//average
+		avg_i += (uint32_t)in1;
+		avg_q += (uint32_t)in2;
+
+		delay_i = cyc_buffer_i[cycle];
+		delay_q = cyc_buffer_q[cycle];
+		
+		cyc_buffer_i[cycle] = avg_i;
+		cyc_buffer_q[cycle] = avg_q;
+		cycle = cycle + 1;
+		if ( cycle >= n )
+		{
+			cycle = 0;
+		}
+
+		out1 = (avg_i - delay_i)/n;
+		out2 = (avg_q - delay_q)/n;
+
+		buf[i]   = out1;
+		buf[i+1] = out2;
+
+		//printf("%d,avg=[%d,%d],delay=[%d,%d],in=[%d,%d],out=[%d,%d]\n",
+		//	cycle, avg_i,avg_q,delay_i,delay_q,in1,in2,out1,out2);
+
+	}
+}
\ No newline at end of file
diff --git a/src/filt/make.mk b/src/filt/make.mk
new file mode 100644
index 0000000..51aa82a
--- /dev/null
+++ b/src/filt/make.mk
@@ -0,0 +1,11 @@
+DIR_FILT = filt/
+SOURCES_FILT += $(SRC_DIR)filt/filt_5th.c $(SRC_DIR)filt/filt_delay.c
+OBJECTS_FILT += $(SOURCES_FILT:.c=.o)
+LDFLAGS += 
+LDFLAGS_BSD +=
+
+
+OBJECTS_DIR_FILT += $(subst $(SRC_DIR)$(DIR_FILT),$(BUILD_DIR)$(SRC_DIR)$(DIR_FILT),$(OBJECTS_FILT))
+
+OBJECTS += $(OBJECTS_FILT)
+OBJECTS_FINAL += $(OBJECTS_DIR_FILT)
\ No newline at end of file
-- 
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