repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
1 | /* |
| 2 | * This file is part of FFmpeg. | |
| 3 | * | |
| 4 | * FFmpeg is free software; you can redistribute it and/or | |
| 5 | * modify it under the terms of the GNU Lesser General Public | |
| 6 | * License as published by the Free Software Foundation; either | |
| 7 | * version 2.1 of the License, or (at your option) any later version. | |
| 8 | * | |
| 9 | * FFmpeg is distributed in the hope that it will be useful, | |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 12 | * Lesser General Public License for more details. | |
| 13 | * | |
| 14 | * You should have received a copy of the GNU Lesser General Public | |
| 15 | * License along with FFmpeg; if not, write to the Free Software | |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 17 | */ | |
| 18 | ||
| 19 | #ifndef AVCODEC_AVFFT_H | |
| 20 | #define AVCODEC_AVFFT_H | |
| 21 | ||
| 22 | /** | |
| 23 | * @file | |
| 24 | * @ingroup lavc_fft | |
| 25 | * FFT functions | |
| 26 | */ | |
| 27 | ||
| 28 | /** | |
| 29 | * @defgroup lavc_fft FFT functions | |
| 30 | * @ingroup lavc_misc | |
| 31 | * | |
| 32 | * @{ | |
| 33 | */ | |
| 34 | ||
| 35 | typedef float FFTSample; | |
| 36 | ||
| 37 | typedef struct FFTComplex { | |
| 38 | FFTSample re, im; | |
| 39 | } FFTComplex; | |
| 40 | ||
| 41 | typedef struct FFTContext FFTContext; | |
| 42 | ||
| 43 | /** | |
| 44 | * Set up a complex FFT. | |
| 45 | * @param nbits log2 of the length of the input array | |
| 46 | * @param inverse if 0 perform the forward transform, if 1 perform the inverse | |
| 47 | */ | |
| 48 | FFTContext *av_fft_init(int nbits, int inverse); | |
| 49 | ||
| 50 | /** | |
| 51 | * Do the permutation needed BEFORE calling ff_fft_calc(). | |
| 52 | */ | |
| 53 | void av_fft_permute(FFTContext *s, FFTComplex *z); | |
| 54 | ||
| 55 | /** | |
| 56 | * Do a complex FFT with the parameters defined in av_fft_init(). The | |
| 57 | * input data must be permuted before. No 1.0/sqrt(n) normalization is done. | |
| 58 | */ | |
| 59 | void av_fft_calc(FFTContext *s, FFTComplex *z); | |
| 60 | ||
| 61 | void av_fft_end(FFTContext *s); | |
| 62 | ||
| 63 | FFTContext *av_mdct_init(int nbits, int inverse, double scale); | |
| 64 | void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input); | |
| 65 | void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input); | |
| 66 | void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input); | |
| 67 | void av_mdct_end(FFTContext *s); | |
| 68 | ||
| 69 | /* Real Discrete Fourier Transform */ | |
| 70 | ||
| 71 | enum RDFTransformType { | |
| 72 | DFT_R2C, | |
| 73 | IDFT_C2R, | |
| 74 | IDFT_R2C, | |
| 75 | DFT_C2R, | |
| 76 | }; | |
| 77 | ||
| 78 | typedef struct RDFTContext RDFTContext; | |
| 79 | ||
| 80 | /** | |
| 81 | * Set up a real FFT. | |
| 82 | * @param nbits log2 of the length of the input array | |
| 83 | * @param trans the type of transform | |
| 84 | */ | |
| 85 | RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans); | |
| 86 | void av_rdft_calc(RDFTContext *s, FFTSample *data); | |
| 87 | void av_rdft_end(RDFTContext *s); | |
| 88 | ||
| 89 | /* Discrete Cosine Transform */ | |
| 90 | ||
| 91 | typedef struct DCTContext DCTContext; | |
| 92 | ||
| 93 | enum DCTTransformType { | |
| 94 | DCT_II = 0, | |
| 95 | DCT_III, | |
| 96 | DCT_I, | |
| 97 | DST_I, | |
| 98 | }; | |
| 99 | ||
| 100 | /** | |
| 101 | * Set up DCT. | |
| 102 | * | |
| 103 | * @param nbits size of the input array: | |
| 104 | * (1 << nbits) for DCT-II, DCT-III and DST-I | |
| 105 | * (1 << nbits) + 1 for DCT-I | |
| 106 | * @param type the type of transform | |
| 107 | * | |
| 108 | * @note the first element of the input of DST-I is ignored | |
| 109 | */ | |
| 110 | DCTContext *av_dct_init(int nbits, enum DCTTransformType type); | |
| 111 | void av_dct_calc(DCTContext *s, FFTSample *data); | |
| 112 | void av_dct_end (DCTContext *s); | |
| 113 | ||
| 114 | /** | |
| 115 | * @} | |
| 116 | */ | |
| 117 | ||
| 118 | #endif /* AVCODEC_AVFFT_H */ |