avfft.h

См. документацию.

/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
 
#ifndef AVCODEC_AVFFT_H
#define AVCODEC_AVFFT_H
 
typedef float FFTSample;
 
typedef struct FFTComplex {
    FFTSample re, im;
} FFTComplex;
 
typedef struct FFTContext FFTContext;
 
FFTContext *av_fft_init(int nbits, int inverse);
 
void av_fft_permute(FFTContext *s, FFTComplex *z);
 
void av_fft_calc(FFTContext *s, FFTComplex *z);
 
void av_fft_end(FFTContext *s);
 
FFTContext *av_mdct_init(int nbits, int inverse, double scale);
void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
void av_mdct_end(FFTContext *s);
 
/* Real Discrete Fourier Transform */
 
enum RDFTransformType {
    DFT_R2C,
    IDFT_C2R,
    IDFT_R2C,
    DFT_C2R,
};
 
typedef struct RDFTContext RDFTContext;
 
RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans);
void av_rdft_calc(RDFTContext *s, FFTSample *data);
void av_rdft_end(RDFTContext *s);
 
/* Discrete Cosine Transform */
 
typedef struct DCTContext DCTContext;
 
enum DCTTransformType {
    DCT_II = 0,
    DCT_III,
    DCT_I,
    DST_I,
};
 
DCTContext *av_dct_init(int nbits, enum DCTTransformType type);
void av_dct_calc(DCTContext *s, FFTSample *data);
void av_dct_end (DCTContext *s);
 
#endif /* AVCODEC_AVFFT_H */