Fixed even more docs

README.md

@@ -329,6 +329,10 @@ It performs a bandpass FIR filter on complex samples, using FFT and the overlap-
 
 Parameters are described under `firdes_bandpass_c` and `firdes_lowpass_f`.
 
+	old_fractional_decimator_ff <decimation_rate> [num_poly_points [transition_bw [window]]]
+
+This is the deprecated, old version of `fractional_decimator_ff` (only uses linear interpolation, its filter cuts at 59% of the passband).
+
 	agc_ff [hang_time [reference [attack_rate [decay_rate [max_gain [attack_wait [filter_alpha]]]]]]]
 
 It is an automatic gain control function.

libcsdr.c

@@ -767,6 +767,7 @@ void fractional_decimator_ff(float* input, float* output, int input_size, fracti
 }
 
 /*
+ * Some notes to myself on the circular buffer I wanted to implement here:
 		int last_input_samplewhere_shouldbe = (index_high-1)+xifirst;
 		int last_input_offset = last_input_samplewhere_shouldbe - d->last_input_samplewhere;
 		if(last_input_offset < num_poly_points)
@@ -781,6 +782,7 @@ void fractional_decimator_ff(float* input, float* output, int input_size, fracti
 			}
 			d->last_input_samplewhere = d->las
 		}
+	However, I think I should just rather do a continuous big buffer.
 */
 
 void apply_fir_fft_cc(FFT_PLAN_T* plan, FFT_PLAN_T* plan_inverse, complexf* taps_fft, complexf* last_overlap, int overlap_size)