From 6efdf7c8097eddbd0b0437043cbd4a4b4260fd21 Mon Sep 17 00:00:00 2001
From: ha7ilm <retzlerandras@gmail.com>
Date: Sun, 22 Nov 2015 15:43:52 +0100
Subject: [PATCH] Enabled the filter, the FFT of which also had to be swapped.
 Fixed the shift direction.

---
 csdr.c                     |  7 ++--
 fastddc.c                  |  8 ++---
 fastddc.h                  |  1 +
 grc_tests/test_fastddc.grc | 65 ++++++++++++++++++++++++++++++++++++--
 4 files changed, 72 insertions(+), 9 deletions(-)

diff --git a/csdr.c b/csdr.c
index c7ada5b..18472d6 100644
--- a/csdr.c
+++ b/csdr.c
@@ -1725,9 +1725,10 @@ int main(int argc, char *argv[])
 
 		//make the filter
 		float filter_half_bw = 0.5/decimation;
-		fprintf(stderr, "fastddc_inv_cc: preparing a bandpass filter of [%g, %g] cutoff rates. Real transition bandwidth is: %g\n", shift_rate-filter_half_bw, shift_rate+filter_half_bw, 4.0/ddc.taps_length);
-		firdes_bandpass_c(taps, ddc.taps_length, shift_rate-filter_half_bw, shift_rate+filter_half_bw, window);
+		fprintf(stderr, "fastddc_inv_cc: preparing a bandpass filter of [%g, %g] cutoff rates. Real transition bandwidth is: %g\n", (-shift_rate)-filter_half_bw, (-shift_rate)+filter_half_bw, 4.0/ddc.taps_length);
+		firdes_bandpass_c(taps, ddc.taps_length, (-shift_rate)-filter_half_bw, (-shift_rate)+filter_half_bw, window);
 		fft_execute(plan_taps);
+		fft_swap_sides(taps_fft,ddc.fft_size);
 
 		//make FFT plan
 		complexf* inv_input = 	 (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_inv_size);
@@ -1748,7 +1749,7 @@ int main(int argc, char *argv[])
 			fread(input, sizeof(complexf), ddc.fft_size, stdin);
 			shift_stat = fastddc_inv_cc(input, output, &ddc, plan_inverse, taps_fft, shift_stat);
 			fwrite(output, sizeof(complexf), shift_stat.output_size, stdout);
-			fprintf(stderr, "ss os = %d\n", shift_stat.output_size);
+			//fprintf(stderr, "ss os = %d\n", shift_stat.output_size);
 			TRY_YIELD;
 		}
 	}
diff --git a/fastddc.c b/fastddc.c
index 9aab721..1e41043 100644
--- a/fastddc.c
+++ b/fastddc.c
@@ -133,10 +133,10 @@ decimating_shift_addition_status_t fastddc_inv_cc(complexf* input, complexf* out
 		// b = qof(input,i)
 		// c = iof(taps_fft,i)
 		// d = qof(taps_fft,i)
-		//iof(inv_input,output_index) += iof(input,i) * iof(taps_fft,i) - qof(input,i) * qof(taps_fft,i);
-		//qof(inv_input,output_index) += iof(input,i) * qof(taps_fft,i) + qof(input,i) * iof(taps_fft,i);
-		iof(inv_input,output_index) += iof(input,i); //no filter
-		qof(inv_input,output_index) += qof(input,i);		
+		iof(inv_input,output_index) += iof(input,i) * iof(taps_fft,i) - qof(input,i) * qof(taps_fft,i);
+		qof(inv_input,output_index) += iof(input,i) * qof(taps_fft,i) + qof(input,i) * iof(taps_fft,i);
+		//iof(inv_input,output_index) += iof(input,i); //no filter
+		//qof(inv_input,output_index) += qof(input,i);		
 	}
 
 	//Normalize inv fft bins (now our output level is not higher than the input... but we may optimize this into the later loop when we normalize by size)
diff --git a/fastddc.h b/fastddc.h
index a948083..d65ca3c 100644
--- a/fastddc.h
+++ b/fastddc.h
@@ -26,3 +26,4 @@ typedef struct fastddc_s
 int fastddc_init(fastddc_t* ddc, float transition_bw, int decimation, float shift_rate);
 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, char* source);
+void fft_swap_sides(complexf* io, int fft_size);
diff --git a/grc_tests/test_fastddc.grc b/grc_tests/test_fastddc.grc
index 099e75b..492fcab 100644
--- a/grc_tests/test_fastddc.grc
+++ b/grc_tests/test_fastddc.grc
@@ -182,6 +182,61 @@
       <value>250000</value>
     </param>
   </block>
+  <block>
+    <key>analog_noise_source_x</key>
+    <param>
+      <key>amp</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>comment</key>
+      <value></value>
+    </param>
+    <param>
+      <key>affinity</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(224, 403)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>id</key>
+      <value>analog_noise_source_x_0</value>
+    </param>
+    <param>
+      <key>maxoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>minoutbuf</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>analog.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>0</value>
+    </param>
+  </block>
   <block>
     <key>analog_sig_source_x</key>
     <param>
@@ -202,7 +257,7 @@
     </param>
     <param>
       <key>_enabled</key>
-      <value>True</value>
+      <value>1</value>
     </param>
     <param>
       <key>freq</key>
@@ -308,7 +363,7 @@
     </param>
     <param>
       <key>commandline</key>
-      <value>csdr fastddc_fwd_cc 4 | csdr fastddc_inv_cc 4 0.1</value>
+      <value>csdr fastddc_fwd_cc 4 | csdr fastddc_inv_cc 4 -0.1</value>
     </param>
     <param>
       <key>comment</key>
@@ -683,6 +738,12 @@
       <value>Counts</value>
     </param>
   </block>
+  <connection>
+    <source_block_id>analog_noise_source_x_0</source_block_id>
+    <sink_block_id>blocks_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
   <connection>
     <source_block_id>analog_sig_source_x_0</source_block_id>
     <sink_block_id>blocks_throttle_0</sink_block_id>