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/*
* Copyright (C) 2001 Anders Johansson ajh@atri.curtin.edu.au
*
* This file is part of MPlayer.
*
* MPlayer 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.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#if !defined MPLAYER_DSP_H
# error Never use filter.h directly; include dsp.h instead.
#endif
#ifndef MPLAYER_FILTER_H
#define MPLAYER_FILTER_H
// Design and implementation of different types of digital filters
// Flags used for filter design
// Filter characteristics
#define LP 0x00010000 // Low pass
#define HP 0x00020000 // High pass
#define BP 0x00040000 // Band pass
#define BS 0x00080000 // Band stop
#define TYPE_MASK 0x000F0000
// Window types
#define BOXCAR 0x00000001
#define TRIANG 0x00000002
#define HAMMING 0x00000004
#define HANNING 0x00000008
#define BLACKMAN 0x00000010
#define FLATTOP 0x00000011
#define KAISER 0x00000012
#define WINDOW_MASK 0x0000001F
// Parallel filter design
#define FWD 0x00000001 // Forward indexing of polyphase filter
#define REW 0x00000002 // Reverse indexing of polyphase filter
#define ODD 0x00000010 // Make filter HP
// Exported functions
FLOAT_TYPE af_filter_fir(unsigned int n, const FLOAT_TYPE* w, const FLOAT_TYPE* x);
int af_filter_design_fir(unsigned int n, FLOAT_TYPE* w, const FLOAT_TYPE* fc,
unsigned int flags, FLOAT_TYPE opt);
int af_filter_szxform(const FLOAT_TYPE* a, const FLOAT_TYPE* b, FLOAT_TYPE Q,
FLOAT_TYPE fc, FLOAT_TYPE fs, FLOAT_TYPE *k,
FLOAT_TYPE *coef);
/* Add new data to circular queue designed to be used with a FIR
filter. xq is the circular queue, in pointing at the new sample, xi
current index for xq and n the length of the filter. xq must be n*2
long.
*/
#define af_filter_updateq(n,xi,xq,in)\
xq[xi]=(xq)[(xi)+(n)]=*(in);\
xi=(++(xi))&((n)-1);
#endif /* MPLAYER_FILTER_H */
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