diff --git a/csdr.c b/csdr.c
index fc46ee4..0e02ceb 100644
--- a/csdr.c
+++ b/csdr.c
@@ -1714,7 +1714,7 @@ int main(int argc, char *argv[])
 		fastddc_print(&ddc);
 
 		if(!initialize_buffers()) return -2;
-		sendbufsize(ddc.output_size);
+		sendbufsize(ddc.post_input_size/ddc.post_decimation); //TODO not exactly correct
 
 		//prepare making the filter and doing FFT on it
 		complexf* taps=(complexf*)calloc(sizeof(complexf),ddc.fft_size); //initialize to zero
@@ -1735,7 +1735,7 @@ int main(int argc, char *argv[])
 		
 		//alloc. buffers
 		complexf* input = 	 (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_size);
-		complexf* output =   (complexf*)fft_malloc(sizeof(complexf)*ddc.output_size);
+		complexf* output =   (complexf*)fft_malloc(sizeof(complexf)*ddc.post_input_size);
 
 		decimating_shift_addition_status_t shift_stat;
 		bzero(&shift_stat, sizeof(shift_stat));
@@ -1744,7 +1744,7 @@ int main(int argc, char *argv[])
 			FEOF_CHECK;
 			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), ddc.output_size, stdout);
+			fwrite(output, sizeof(complexf), shift_stat.output_size, stdout);
 			TRY_YIELD;
 		}
 	}
diff --git a/fastddc.c b/fastddc.c
index 7a76234..4cd45ae 100644
--- a/fastddc.c
+++ b/fastddc.c
@@ -63,7 +63,7 @@ int fastddc_init(fastddc_t* ddc, float transition_bw, int decimation, float shif
 
 	//Overlap is scraped, not added
 	ddc->scrape=ddc->overlap_length/ddc->pre_decimation;
-	ddc->output_size=ddc->fft_inv_size-ddc->scrape;
+	ddc->post_input_size=ddc->fft_inv_size-ddc->scrape;
 
 	return ddc->fft_size<=2; //returns true on error
 }
@@ -76,13 +76,13 @@ void fastddc_print(fastddc_t* ddc)
 		"  overlap     ::  (overlap_length = %d) = taps_length - 1, taps_real_length = %d\n"
 		"  decimation  ::  decimation = (pre_decimation = %d) * (post_decimation = %d), fft_inv_size = %d\n"
 		"  shift       ::  startbin = %d, offsetbin = %d, v = %d, pre_shift = %g, post_shift = %g\n"
-		"  o&s         ::  output_size = %d, scrape = %d\n"
+		"  o&s         ::  post_input_size = %d, scrape = %d\n"
 		, 
 		ddc->fft_size, ddc->taps_length, ddc->input_size, 
 		ddc->overlap_length, ddc->taps_real_length,
 		ddc->pre_decimation, ddc->post_decimation, ddc->fft_inv_size,
 		ddc->startbin, ddc->offsetbin, ddc->v, ddc->pre_shift, ddc->post_shift, 
-		ddc->output_size, ddc->scrape );
+		ddc->post_input_size, ddc->scrape );
 }
 
 void fft_swap_sides(complexf* io, int fft_size)
@@ -138,6 +138,8 @@ decimating_shift_addition_status_t fastddc_inv_cc(complexf* input, complexf* out
 	//Overlap is scraped, not added
 	//Shift correction
 	shift_addition_data_t dsadata=decimating_shift_addition_init(ddc->post_shift, ddc->post_decimation); //this could be optimized (passed as parameter), but we would not win too much at all 
-	shift_stat=decimating_shift_addition_cc(inv_output+ddc->scrape, output, ddc->output_size, dsadata, ddc->post_decimation, shift_stat);
+	shift_stat=decimating_shift_addition_cc(inv_output+ddc->scrape, output, ddc->post_input_size, dsadata, ddc->post_decimation, shift_stat);
+	
+	//memcpy(inv_output+ddc->scrape,  
 	return shift_stat;
 }
diff --git a/fastddc.h b/fastddc.h
index e4aae2e..1e27cef 100644
--- a/fastddc.h
+++ b/fastddc.h
@@ -12,7 +12,7 @@ typedef struct fastddc_s
 	int fft_size;
 	int fft_inv_size;
 	int input_size;
-	int output_size;
+	int post_input_size;
 	float pre_shift;
 	int startbin; //for pre_shift
 	int v; //step for pre_shift
diff --git a/grc_tests/test_fastddc.grc b/grc_tests/test_fastddc.grc
index 5c3706e..79d064f 100644
--- a/grc_tests/test_fastddc.grc
+++ b/grc_tests/test_fastddc.grc
@@ -281,7 +281,7 @@
     </param>
     <param>
       <key>commandline</key>
-      <value>csdr fastddc_fwd_cc 10 | csdr fastddc_apply_cc 10 0.1 | csdr floatdump_f 2&gt;&amp;1 | head -n 100</value>
+      <value>csdr fastddc_fwd_cc 10 | csdr fastddc_inv_cc 10 0.1</value>
     </param>
     <param>
       <key>comment</key>