From 175c700cc9ce2e84922eab50f6019ab27ce9c82a Mon Sep 17 00:00:00 2001
From: ha7ilm <retzlerandras@gmail.com>
Date: Tue, 17 Nov 2015 21:54:06 +0100
Subject: [PATCH] Verified that fastddc_fwd_cc works.

---
 csdr.c    | 35 +++++++++++++++++++++++++++++++----
 fastddc.c | 22 +++++++++++++++++++---
 fastddc.h |  2 +-
 3 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/csdr.c b/csdr.c
index 55ce462..fc46ee4 100644
--- a/csdr.c
+++ b/csdr.c
@@ -697,7 +697,7 @@ int main(int argc, char *argv[])
 		{
 			FEOF_CHECK;
 			FREAD_R;
-			for(int i=0; i<the_bufsize;i++) fprintf(stderr, "%g ",input_buffer[i]);
+			for(int i=0; i<the_bufsize;i++) printf("%g ",input_buffer[i]);
 			TRY_YIELD;
 		}
 		
@@ -1658,7 +1658,7 @@ int main(int argc, char *argv[])
 		if(argc>3) sscanf(argv[3],"%g",&transition_bw);
 
 		window_t window = WINDOW_DEFAULT;
-		if(argc>4)	window=firdes_get_window_from_string(argv[5]);
+		if(argc>4)	window=firdes_get_window_from_string(argv[4]);
 		else fprintf(stderr,"fastddc_fwd_cc: window = %s\n",firdes_get_string_from_window(window));
 
 		fastddc_t ddc; 
@@ -1693,7 +1693,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if( !strcmp(argv[1],"fastddc_apply_cc") ) //<decimation> <shift_rate> [transition_bw [window]]
+	if( !strcmp(argv[1],"fastddc_inv_cc") ) //<decimation> <shift_rate> [transition_bw [window]]
 	{	
 		int decimation;
 		if(argc<=2) return badsyntax("need required parameter (decimation)");
@@ -1743,12 +1743,39 @@ int main(int argc, char *argv[])
 		{
 			FEOF_CHECK;
 			fread(input, sizeof(complexf), ddc.fft_size, stdin);
-			shift_stat = fastddc_apply_cc(input, output, &ddc, plan_inverse, taps_fft, shift_stat);
+			shift_stat = fastddc_inv_cc(input, output, &ddc, plan_inverse, taps_fft, shift_stat);
 			fwrite(output, sizeof(complexf), ddc.output_size, stdout);
 			TRY_YIELD;
 		}
 	}
 
+	if( !strcmp(argv[1], "_fft2octave") ) 
+	{
+		int fft_size;
+		if(argc<=2) return badsyntax("need required parameter (fft_size)");
+		sscanf(argv[2],"%d",&fft_size);
+
+		complexf* fft_input=(complexf*)malloc(sizeof(complexf)*fft_size);
+		initialize_buffers();
+		if(!sendbufsize(fft_size)) return -2;
+
+		printf("setenv(\"GNUTERM\",\"X11 noraise\");y=zeros(1,%d);semilogy(y,\"ydatasource\",\"y\");\n",fft_size);
+		for(;;)
+		{
+			FEOF_CHECK;
+			fread(fft_input, sizeof(complexf), fft_size, stdin);
+			printf("fftdata=[");
+			//we have to swap the two parts of the array to get a valid spectrum
+			for(int i=fft_size/2;i<fft_size;i++) printf("(%g)+(%g)*i ",iof(fft_input,i),qof(fft_input,i));
+			for(int i=0;i<fft_size/2;i++) printf("(%g)+(%g)*i ",iof(fft_input,i),qof(fft_input,i)); 
+			printf(
+				"];\n"
+				"y=abs(fftdata);\n"
+				"refreshdata;\n"
+			);
+		}
+	}
+
 	if(!strcmp(argv[1],"none"))
 	{
 		return 0;
diff --git a/fastddc.c b/fastddc.c
index baaf597..7a76234 100644
--- a/fastddc.c
+++ b/fastddc.c
@@ -85,7 +85,22 @@ void fastddc_print(fastddc_t* ddc)
 		ddc->output_size, ddc->scrape );
 }
 
-decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat)
+void fft_swap_sides(complexf* io, int fft_size)
+{
+	int middle=fft_size/2;
+	complexf temp;
+	for(int i=0;i<middle;i++)
+	{
+		iof(&temp,0)=iof(io,i);
+		qof(&temp,0)=qof(io,i);
+		iof(io,i)=iof(io,i+middle);
+		qof(io,i)=qof(io,i+middle);
+		iof(io,i+middle)=iof(&temp,0);
+		qof(io,i+middle)=qof(&temp,0);
+	}
+}
+
+decimating_shift_addition_status_t fastddc_inv_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat)
 {
 	//implements DDC by using the overlap & scrape method
 	//TODO: +/-1s on overlap_size et al
@@ -102,7 +117,7 @@ decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* o
 	}
 
 	//Alias & shift & filter at once
-	// * no, we won't break this algorithm to parts that are easier to understand: now we go for speed
+	fft_swap_sides(input, ddc->fft_size); //this is not very optimal, but now we stick with this slow solution until we got the algorithm working
 	for(int i=0;i<ddc->fft_size;i++)
 	{
 		int output_index = (ddc->startbin+i)%plan_inverse->size;
@@ -111,9 +126,10 @@ decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* o
 	}
 
 	fft_execute(plan_inverse);
+	fft_swap_sides(inv_output,plan_inverse->size);
 
 	//Normalize data
-	for(int i=0;i<plan_inverse->size;i++) //@apply_ddc_fft_cc: normalize by size
+	for(int i=0;i<plan_inverse->size;i++) //@fastddc_inv_cc: normalize by size
 	{
 		iof(inv_output,i)/=plan_inverse->size;
 		qof(inv_output,i)/=plan_inverse->size;
diff --git a/fastddc.h b/fastddc.h
index 0029713..e4aae2e 100644
--- a/fastddc.h
+++ b/fastddc.h
@@ -23,5 +23,5 @@ typedef struct fastddc_s
 } fastddc_t;
 
 int fastddc_init(fastddc_t* ddc, float transition_bw, int decimation, float shift_rate);
-decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat);
+decimating_shift_addition_status_t fastddc_inv_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat);
 void fastddc_print(fastddc_t* ddc);