mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-28 20:53:54 +02:00
100 lines
2.8 KiB
C
100 lines
2.8 KiB
C
/*
|
|
* 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;
|
|
|
|
/**
|
|
* Set up a complex FFT.
|
|
* @param nbits log2 of the length of the input array
|
|
* @param inverse if 0 perform the forward transform, if 1 perform the inverse
|
|
*/
|
|
FFTContext *av_fft_init(int nbits, int inverse);
|
|
|
|
/**
|
|
* Do the permutation needed BEFORE calling ff_fft_calc().
|
|
*/
|
|
void av_fft_permute(FFTContext *s, FFTComplex *z);
|
|
|
|
/**
|
|
* Do a complex FFT with the parameters defined in av_fft_init(). The
|
|
* input data must be permuted before. No 1.0/sqrt(n) normalization is done.
|
|
*/
|
|
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;
|
|
|
|
/**
|
|
* Set up a real FFT.
|
|
* @param nbits log2 of the length of the input array
|
|
* @param trans the type of transform
|
|
*/
|
|
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,
|
|
};
|
|
|
|
/**
|
|
* Sets up DCT.
|
|
* @param nbits size of the input array:
|
|
* (1 << nbits) for DCT-II, DCT-III and DST-I
|
|
* (1 << nbits) + 1 for DCT-I
|
|
*
|
|
* @note the first element of the input of DST-I is ignored
|
|
*/
|
|
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 */
|