/* * SpanDSP - a series of DSP components for telephony * * filter_tools.h - A collection of routines used for filter design. * * Written by Steve Underwood * * Copyright (C) 2008 Steve Underwood * * Based on: * mkshape -- design raised cosine FIR filter * A.J. Fisher, University of York , November 1996 * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1, * as published by the Free Software Foundation. * * This program 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #if !defined(_FILTER_TOOLS_H_) #define _FILTER_TOOLS_H_ #if defined(__cplusplus) extern "C" { #endif void ifft(complex_t data[], int len); void apply_hamming_window(double coeffs[], int len); void truncate_coeffs(double coeffs[], int len, int bits, int hilbert); void compute_raised_cosine_filter(double coeffs[], int len, int root, int sinc_compensate, double alpha, double beta); void compute_hilbert_transform(double coeffs[], int len); #if defined(__cplusplus) } #endif #endif /*- End of file ------------------------------------------------------------*/