Libav 0.7.1
libavcodec/iirfilter.h
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00001 /*
00002  * IIR filter
00003  * Copyright (c) 2008 Konstantin Shishkov
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav 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 GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #ifndef AVCODEC_IIRFILTER_H
00028 #define AVCODEC_IIRFILTER_H
00029 
00030 #include "avcodec.h"
00031 
00032 struct FFIIRFilterCoeffs;
00033 struct FFIIRFilterState;
00034 
00035 enum IIRFilterType{
00036     FF_FILTER_TYPE_BESSEL,
00037     FF_FILTER_TYPE_BIQUAD,
00038     FF_FILTER_TYPE_BUTTERWORTH,
00039     FF_FILTER_TYPE_CHEBYSHEV,
00040     FF_FILTER_TYPE_ELLIPTIC,
00041 };
00042 
00043 enum IIRFilterMode{
00044     FF_FILTER_MODE_LOWPASS,
00045     FF_FILTER_MODE_HIGHPASS,
00046     FF_FILTER_MODE_BANDPASS,
00047     FF_FILTER_MODE_BANDSTOP,
00048 };
00049 
00064 struct FFIIRFilterCoeffs* ff_iir_filter_init_coeffs(void *avc,
00065                                                 enum IIRFilterType filt_type,
00066                                                 enum IIRFilterMode filt_mode,
00067                                                 int order, float cutoff_ratio,
00068                                                 float stopband, float ripple);
00069 
00077 struct FFIIRFilterState* ff_iir_filter_init_state(int order);
00078 
00084 void ff_iir_filter_free_coeffs(struct FFIIRFilterCoeffs *coeffs);
00085 
00091 void ff_iir_filter_free_state(struct FFIIRFilterState *state);
00092 
00104 void ff_iir_filter(const struct FFIIRFilterCoeffs *coeffs, struct FFIIRFilterState *state,
00105                    int size, const int16_t *src, int sstep, int16_t *dst, int dstep);
00106 
00118 void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *coeffs,
00119                        struct FFIIRFilterState *state, int size,
00120                        const float *src, int sstep, float *dst, int dstep);
00121 
00122 #endif /* AVCODEC_IIRFILTER_H */