FFmpeg: libavcodec/fft.h Source File

00001 /*
00002  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
00003  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #ifndef AVCODEC_FFT_H
00023 #define AVCODEC_FFT_H
00024 
00025 #include <stdint.h>
00026 #include "config.h"
00027 #include "libavutil/mem.h"
00028 #include "avfft.h"
00029 
00030 /* FFT computation */
00031 
00032 struct FFTContext {
00033     int nbits;
00034     int inverse;
00035     uint16_t *revtab;
00036     FFTComplex *tmp_buf;
00037     int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
00038     int mdct_bits; /* n = 2^nbits */
00039     /* pre/post rotation tables */
00040     FFTSample *tcos;
00041     FFTSample *tsin;
00045     void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
00050     void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
00051     void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00052     void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00053     void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
00054     int fft_permutation;
00055 #define FF_FFT_PERM_DEFAULT   0
00056 #define FF_FFT_PERM_SWAP_LSBS 1
00057     int mdct_permutation;
00058 #define FF_MDCT_PERM_NONE       0
00059 #define FF_MDCT_PERM_INTERLEAVE 1
00060 };
00061 
00062 #if CONFIG_HARDCODED_TABLES
00063 #define COSTABLE_CONST const
00064 #else
00065 #define COSTABLE_CONST
00066 #endif
00067 
00068 #define COSTABLE(size) \
00069     COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
00070 
00071 extern COSTABLE(16);
00072 extern COSTABLE(32);
00073 extern COSTABLE(64);
00074 extern COSTABLE(128);
00075 extern COSTABLE(256);
00076 extern COSTABLE(512);
00077 extern COSTABLE(1024);
00078 extern COSTABLE(2048);
00079 extern COSTABLE(4096);
00080 extern COSTABLE(8192);
00081 extern COSTABLE(16384);
00082 extern COSTABLE(32768);
00083 extern COSTABLE(65536);
00084 extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
00085 
00090 void ff_init_ff_cos_tabs(int index);
00091 
00097 int ff_fft_init(FFTContext *s, int nbits, int inverse);
00098 
00099 void ff_fft_init_altivec(FFTContext *s);
00100 void ff_fft_init_mmx(FFTContext *s);
00101 void ff_fft_init_arm(FFTContext *s);
00102 void ff_dct_init_mmx(DCTContext *s);
00103 
00104 void ff_fft_end(FFTContext *s);
00105 
00106 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
00107 void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00108 void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00109 void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
00110 void ff_mdct_end(FFTContext *s);
00111 
00112 #endif /* AVCODEC_FFT_H */