PeerStreamer

/*

 * 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

#include <stdint.h>

#include "config.h"

#include "libavutil/mem.h"

#include "avfft.h"

/* 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;

    void (*fft_permute)(struct FFTContext *s, FFTComplex *z);

    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);

    int permutation;

#define FF_MDCT_PERM_NONE       0

#define FF_MDCT_PERM_INTERLEAVE 1

};

#if CONFIG_HARDCODED_TABLES

#define COSTABLE_CONST const

#define SINTABLE_CONST const

#define SINETABLE_CONST const

#else

#define COSTABLE_CONST

#define SINTABLE_CONST

#define SINETABLE_CONST

#endif

#define COSTABLE(size) \

    COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]

#define SINTABLE(size) \

    SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]

#define SINETABLE(size) \

    SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]

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 ff_cos_tabs[17];

/**

 * 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);

extern SINTABLE(16);

extern SINTABLE(32);

extern SINTABLE(64);

extern SINTABLE(128);

extern SINTABLE(256);

extern SINTABLE(512);

extern SINTABLE(1024);

extern SINTABLE(2048);

extern SINTABLE(4096);

extern SINTABLE(8192);

extern SINTABLE(16384);

extern SINTABLE(32768);

extern SINTABLE(65536);

/**

 * 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_altivec(FFTContext *s);

void ff_fft_init_mmx(FFTContext *s);

void ff_fft_init_arm(FFTContext *s);

void ff_dct_init_mmx(DCTContext *s);

/**

 * Do the permutation needed BEFORE calling ff_fft_calc().

 */

static inline void ff_fft_permute(FFTContext *s, FFTComplex *z)

{

    s->fft_permute(s, 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.

 */

static inline void ff_fft_calc(FFTContext *s, FFTComplex *z)

{

    s->fft_calc(s, z);

}

void ff_fft_end(FFTContext *s);

/* MDCT computation */

static inline void ff_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input)

{

    s->imdct_calc(s, output, input);

}

static inline void ff_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input)

{

    s->imdct_half(s, output, input);

}

static inline void ff_mdct_calc(FFTContext *s, FFTSample *output,

                                const FFTSample *input)

{

    s->mdct_calc(s, output, input);

}

/**

 * Maximum window size for ff_kbd_window_init.

 */

#define FF_KBD_WINDOW_MAX 1024

/**

 * Generate a Kaiser-Bessel Derived Window.

 * @param   window  pointer to half window

 * @param   alpha   determines window shape

 * @param   n       size of half window, max FF_KBD_WINDOW_MAX

 */

void ff_kbd_window_init(float *window, float alpha, int n);

/**

 * Generate a sine window.

 * @param   window  pointer to half window

 * @param   n       size of half window

 */

void ff_sine_window_init(float *window, int n);

/**

 * initialize the specified entry of ff_sine_windows

 */

void ff_init_ff_sine_windows(int index);

extern SINETABLE(  32);

extern SINETABLE(  64);

extern SINETABLE( 128);

extern SINETABLE( 256);

extern SINETABLE( 512);

extern SINETABLE(1024);

extern SINETABLE(2048);

extern SINETABLE(4096);

extern SINETABLE_CONST float * const ff_sine_windows[13];

int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);

void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);

void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);

void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);

void ff_mdct_end(FFTContext *s);

/* Real Discrete Fourier Transform */

struct RDFTContext {

    int nbits;

    int inverse;

    int sign_convention;

    /* pre/post rotation tables */

    const FFTSample *tcos;

    SINTABLE_CONST FFTSample *tsin;

    FFTContext fft;

    void (*rdft_calc)(struct RDFTContext *s, FFTSample *z);

};

/**

 * Set up a real FFT.

 * @param nbits           log2 of the length of the input array

 * @param trans           the type of transform

 */

int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);

void ff_rdft_end(RDFTContext *s);

void ff_rdft_init_arm(RDFTContext *s);

static av_always_inline void ff_rdft_calc(RDFTContext *s, FFTSample *data)

{

    s->rdft_calc(s, data);

}

/* Discrete Cosine Transform */

struct DCTContext {

    int nbits;

    int inverse;

    RDFTContext rdft;

    const float *costab;

    FFTSample *csc2;

    void (*dct_calc)(struct DCTContext *s, FFTSample *data);

    void (*dct32)(FFTSample *out, const FFTSample *in);

};

/**

 * Set 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

 */

int  ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType type);

void ff_dct_calc(DCTContext *s, FFTSample *data);

void ff_dct_end (DCTContext *s);

#endif /* AVCODEC_FFT_H */