diff options
Diffstat (limited to 'filt')
| -rw-r--r-- | filt/filt.h | 7 | ||||
| -rw-r--r-- | filt/filt_5th.c (renamed from filt/f_5th.c) | 2 | ||||
| -rw-r--r-- | filt/filt_delay.c | 51 | ||||
| -rw-r--r-- | filt/make.mk | 2 |
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 += |