mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-21 10:55:51 +02:00
18d7074b4e
Iterative implementation of 32 bit fixed point split-radix FFT. Max FFT that can be calculated currently is 2^12. Signed-off-by: Nedeljko Babic <nbabic@mips.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
167 lines
4.4 KiB
C
167 lines
4.4 KiB
C
/*
|
|
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
|
|
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* 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_FFT_H
|
|
#define AVCODEC_FFT_H
|
|
|
|
#ifndef CONFIG_FFT_FLOAT
|
|
#define CONFIG_FFT_FLOAT 1
|
|
#endif
|
|
|
|
#ifndef CONFIG_FFT_FIXED_32
|
|
#define CONFIG_FFT_FIXED_32 0
|
|
#endif
|
|
|
|
#include <stdint.h>
|
|
#include "config.h"
|
|
#include "libavutil/mem.h"
|
|
|
|
#if CONFIG_FFT_FLOAT
|
|
|
|
#include "avfft.h"
|
|
|
|
#define FFT_NAME(x) x
|
|
|
|
typedef float FFTDouble;
|
|
|
|
#else
|
|
|
|
#if CONFIG_FFT_FIXED_32
|
|
|
|
#define Q31(x) (int)((x)*2147483648.0 + 0.5)
|
|
#define FFT_NAME(x) x ## _fixed_32
|
|
|
|
typedef int32_t FFTSample;
|
|
|
|
#else /* CONFIG_FFT_FIXED_32 */
|
|
|
|
#define FFT_NAME(x) x ## _fixed
|
|
|
|
typedef int16_t FFTSample;
|
|
|
|
#endif /* CONFIG_FFT_FIXED_32 */
|
|
|
|
typedef struct FFTComplex {
|
|
FFTSample re, im;
|
|
} FFTComplex;
|
|
|
|
typedef int FFTDouble;
|
|
typedef struct FFTContext FFTContext;
|
|
|
|
#endif /* CONFIG_FFT_FLOAT */
|
|
|
|
typedef struct FFTDComplex {
|
|
FFTDouble re, im;
|
|
} FFTDComplex;
|
|
|
|
/* FFT computation */
|
|
|
|
struct FFTContext {
|
|
int nbits;
|
|
int inverse;
|
|
uint16_t *revtab;
|
|
FFTComplex *tmp_buf;
|
|
int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
|
|
int mdct_bits; /* n = 2^nbits */
|
|
/* pre/post rotation tables */
|
|
FFTSample *tcos;
|
|
FFTSample *tsin;
|
|
/**
|
|
* Do the permutation needed BEFORE calling fft_calc().
|
|
*/
|
|
void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
|
|
/**
|
|
* Do a complex FFT with the parameters defined in ff_fft_init(). The
|
|
* input data must be permuted before. No 1.0/sqrt(n) normalization is done.
|
|
*/
|
|
void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
|
|
void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
|
|
void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
|
|
void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
|
|
void (*mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input);
|
|
int fft_permutation;
|
|
#define FF_FFT_PERM_DEFAULT 0
|
|
#define FF_FFT_PERM_SWAP_LSBS 1
|
|
#define FF_FFT_PERM_AVX 2
|
|
int mdct_permutation;
|
|
#define FF_MDCT_PERM_NONE 0
|
|
#define FF_MDCT_PERM_INTERLEAVE 1
|
|
};
|
|
|
|
#if CONFIG_HARDCODED_TABLES
|
|
#define COSTABLE_CONST const
|
|
#else
|
|
#define COSTABLE_CONST
|
|
#endif
|
|
|
|
#define COSTABLE(size) \
|
|
COSTABLE_CONST DECLARE_ALIGNED(32, FFTSample, FFT_NAME(ff_cos_##size))[size/2]
|
|
|
|
extern COSTABLE(16);
|
|
extern COSTABLE(32);
|
|
extern COSTABLE(64);
|
|
extern COSTABLE(128);
|
|
extern COSTABLE(256);
|
|
extern COSTABLE(512);
|
|
extern COSTABLE(1024);
|
|
extern COSTABLE(2048);
|
|
extern COSTABLE(4096);
|
|
extern COSTABLE(8192);
|
|
extern COSTABLE(16384);
|
|
extern COSTABLE(32768);
|
|
extern COSTABLE(65536);
|
|
extern COSTABLE_CONST FFTSample* const FFT_NAME(ff_cos_tabs)[17];
|
|
|
|
#define ff_init_ff_cos_tabs FFT_NAME(ff_init_ff_cos_tabs)
|
|
|
|
/**
|
|
* Initialize the cosine table in ff_cos_tabs[index]
|
|
* @param index index in ff_cos_tabs array of the table to initialize
|
|
*/
|
|
void ff_init_ff_cos_tabs(int index);
|
|
|
|
#define ff_fft_init FFT_NAME(ff_fft_init)
|
|
#define ff_fft_end FFT_NAME(ff_fft_end)
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
int ff_fft_init(FFTContext *s, int nbits, int inverse);
|
|
|
|
void ff_fft_init_x86(FFTContext *s);
|
|
void ff_fft_init_arm(FFTContext *s);
|
|
void ff_fft_init_mips(FFTContext *s);
|
|
void ff_fft_init_ppc(FFTContext *s);
|
|
|
|
void ff_fft_fixed_init_arm(FFTContext *s);
|
|
|
|
void ff_fft_end(FFTContext *s);
|
|
|
|
#define ff_mdct_init FFT_NAME(ff_mdct_init)
|
|
#define ff_mdct_end FFT_NAME(ff_mdct_end)
|
|
|
|
int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
|
|
void ff_mdct_end(FFTContext *s);
|
|
|
|
#endif /* AVCODEC_FFT_H */
|