// // cfirfilter.cpp // ambed // // Created by Jean-Luc Deltombe (LX3JL) on 26/04/2017. // Copyright © 2015 Jean-Luc Deltombe (LX3JL). All rights reserved. // // ---------------------------------------------------------------------------- // This file is part of ambed. // // xlxd is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // xlxd is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Foobar. If not, see . // ---------------------------------------------------------------------------- // FIRFilter by Geoffrey Merck F4FXL / KC3FRA #include "cfirfilter.h" #include CFIRFilter::CFIRFilter(const float* taps, int tapsLength) { m_taps = new float[tapsLength]; m_buffer = new float[tapsLength]; m_tapsLength = tapsLength; ::memcpy(m_taps, taps, tapsLength * sizeof(float)); ::memset(m_buffer, 0, tapsLength * sizeof(float)); m_currentBufferPostion = 0; } CFIRFilter::~CFIRFilter() { delete[] m_taps; delete[] m_buffer; } inline float CFIRFilter::Process(float inputSample) { // Buffer latest sample m_buffer[m_currentBufferPostion] = inputSample; float outputSample = 0.0f; for(int i = 0; i < m_tapsLength; i++) { outputSample += m_taps[i] * m_buffer[(m_currentBufferPostion + i) % m_tapsLength]; } m_currentBufferPostion = (m_currentBufferPostion + 1) % m_tapsLength; return outputSample; } void CFIRFilter::Process(uint8* voice, int length) { for(int i = 0; i < length; i++) { //Get the sample float input = (float)(short)MAKEWORD(voice[i+1], voice[i]); float output = Process(input); //write processed sample back voice[i] = HIBYTE((short)output); voice[i+1] = LOBYTE((short)output); } }