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authorFreeArtMan <dos21h@gmail.com>2016-05-08 16:02:01 +0100
committerFreeArtMan <dos21h@gmail.com>2016-05-08 16:02:01 +0100
commite42911405c4bc2f8c097f47d4598baf8522ef3da (patch)
tree9eb767c5e6a4443e8773b18ea76cf4216f6c8758 /src/filt
parent9b95088bddcf1f83e3a8f73f08f49b38ecb0f500 (diff)
downloadradiola-e42911405c4bc2f8c097f47d4598baf8522ef3da.tar.gz
radiola-e42911405c4bc2f8c097f47d4598baf8522ef3da.zip
Moved source to src directoryHEADmaster
Diffstat (limited to 'src/filt')
-rw-r--r--src/filt/Kconfig0
-rw-r--r--src/filt/filt.h16
-rw-r--r--src/filt/filt_5th.c32
-rw-r--r--src/filt/filt_delay.c51
-rw-r--r--src/filt/make.mk11
5 files changed, 110 insertions, 0 deletions
diff --git a/src/filt/Kconfig b/src/filt/Kconfig
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/filt/Kconfig
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