doom3-bfg/doomclassic/timidity/filter.h
2012-11-26 12:58:24 -06:00

35 lines
1.1 KiB
C

/*
TiMidity -- Experimental MIDI to WAVE converter
Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>
This program 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 2 of the License, or
(at your option) any later version.
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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
filter.h : written by Vincent Pagel ( pagel@loria.fr )
implements fir antialiasing filter : should help when setting sample
rates as low as 8Khz.
*/
/* Order of the FIR filter = 20 should be enough ! */
#define ORDER 20
#define ORDER2 ORDER/2
#ifndef PI
extern const float PI;
#endif
extern void antialiasing(Sample *sp, int32_t output_rate);