More configurable sources. Move some math functions to core/math.h. Move delay filter from sdr_fm

4 files changed, 59 insertions, 3 deletions

diff --git a/filt/filt.h b/filt/filt.h
index d235449..9ce2caa 100644
--- a/filt/filt.h
+++ b/filt/filt.h
@@ -3,9 +3,14 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
+#include <string.h>
 #include <unistd.h>
 
 //fifth order filter from rtlsdr
-void f_5th(int16_t *data, int length, int16_t *hist);
+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/filt/f_5th.c b/filt/filt_5th.c
index 811fb18..23d5aab 100644
--- a/filt/f_5th.c
+++ b/filt/filt_5th.c
@@ -29,4 +29,4 @@ void f_5th(int16_t *data, int length, int16_t *hist)
 	hist[3] = d;
 	hist[4] = e;
 	hist[5] = f;
-}
\ No newline at end of file
+}
diff --git a/filt/filt_delay.c b/filt/filt_delay.c
new file mode 100644
index 0000000..53da0b0
--- /dev/null
+++ b/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/filt/make.mk b/filt/make.mk
index bde2fe3..be7468f 100644
--- a/filt/make.mk
+++ b/filt/make.mk
@@ -1,5 +1,5 @@
 DIR_FILT = filt/
-SOURCES_FILT += filt/f_5th.c
+SOURCES_FILT += filt/filt_5th.c filt/filt_delay.c
 OBJECTS_FILT += $(SOURCES_FILT:.c=.o)
 LDFLAGS += 
 LDFLAGS_BSD +=