00001 /* -*- c++ -*- */ 00002 /* 00003 * Copyright 2002,2006 Free Software Foundation, Inc. 00004 * 00005 * This file is part of GNU Radio 00006 * 00007 * GNU Radio is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License as published by 00009 * the Free Software Foundation; either version 3, or (at your option) 00010 * any later version. 00011 * 00012 * GNU Radio is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 * GNU General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU General Public License 00018 * along with GNU Radio; see the file COPYING. If not, write to 00019 * the Free Software Foundation, Inc., 51 Franklin Street, 00020 * Boston, MA 02110-1301, USA. 00021 */ 00022 00023 #ifndef INCLUDED_GRI_AGC_FF_H 00024 #define INCLUDED_GRI_AGC_FF_H 00025 00026 #include <math.h> 00027 00035 class gri_agc_ff { 00036 00037 public: 00038 gri_agc_ff (float rate = 1e-4, float reference = 1.0, 00039 float gain = 1.0, float max_gain = 0.0) 00040 : _rate(rate), _reference(reference), _gain(gain), _max_gain(max_gain) {}; 00041 00042 float rate () const { return _rate; } 00043 float reference () const { return _reference; } 00044 float gain () const { return _gain; } 00045 float max_gain () const { return _max_gain; } 00046 00047 void set_rate (float rate) { _rate = rate; } 00048 void set_reference (float reference) { _reference = reference; } 00049 void set_gain (float gain) { _gain = gain; } 00050 void set_max_gain (float max_gain) { _max_gain = max_gain; } 00051 00052 float scale (float input){ 00053 float output = input * _gain; 00054 _gain += (_reference - fabsf (output)) * _rate; 00055 if (_max_gain > 0.0 && _gain > _max_gain) 00056 _gain = _max_gain; 00057 return output; 00058 } 00059 00060 void scaleN (float output[], const float input[], unsigned n){ 00061 for (unsigned i = 0; i < n; i++) 00062 output[i] = scale (input[i]); 00063 } 00064 00065 protected: 00066 float _rate; // adjustment rate 00067 float _reference; // reference value 00068 float _gain; // current gain 00069 float _max_gain; // maximum gain 00070 }; 00071 00072 #endif /* INCLUDED_GRI_AGC_FF_H */ 00073