00001 /* -*- c++ -*- */ 00002 /* 00003 * Copyright 2002 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 2, 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., 59 Temple Place - Suite 330, 00020 * Boston, MA 02111-1307, USA. 00021 */ 00022 00023 #ifndef _GRI_AGC_H_ 00024 #define _GRI_AGC_H_ 00025 00026 #include <math.h> 00027 00034 class gri_agc { 00035 00036 public: 00037 gri_agc (float rate = 1e-4, float reference = 1.0, float gain = 1.0) 00038 : _rate(rate), _reference(reference), _gain(gain) {}; 00039 00040 float rate () const { return _rate; } 00041 float reference () const { return _reference; } 00042 float gain () const { return _gain; } 00043 00044 void set_rate (float rate) { _rate = rate; } 00045 void set_reference (float reference) { _reference = reference; } 00046 void set_gain (float gain) { _gain = gain; } 00047 00048 float scale (float input){ 00049 float output = input * _gain; 00050 _gain += (_reference - fabsf (output)) * _rate; 00051 return output; 00052 } 00053 00054 void scaleN (float output[], const float input[], unsigned n){ 00055 for (unsigned i = 0; i < n; i++) 00056 output[i] = scale (input[i]); 00057 } 00058 00059 protected: 00060 float _rate; // adjustment rate 00061 float _reference; // reference value 00062 float _gain; // current gain 00063 }; 00064 00065 #endif /* _GRI_AGC_H_ */