libavcodec/fft-internal.h File Reference

#include "libavutil/intmath.h"
#include "mathops.h"

Go to the source code of this file.

Defines
#define	SCALE_FLOAT(a, bits)   lrint((a) * (double)(1 << (bits)))
#define	FIX15(a)   av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
#define	sqrthalf   ((int16_t)((1<<15)*M_SQRT1_2))
#define	BF(x, y, a, b)
#define	CMULS(dre, dim, are, aim, bre, bim, sh)
#define	CMUL(dre, dim, are, aim, bre, bim)   CMULS(dre, dim, are, aim, bre, bim, 15)
#define	CMULL(dre, dim, are, aim, bre, bim)   CMULS(dre, dim, are, aim, bre, bim, 0)
#define	ff_imdct_calc_c   FFT_NAME(ff_imdct_calc_c)
#define	ff_imdct_half_c   FFT_NAME(ff_imdct_half_c)
#define	ff_mdct_calc_c   FFT_NAME(ff_mdct_calc_c)
Functions
void	ff_mdct_calcw_c (FFTContext *s, FFTDouble *output, const FFTSample *input)
void	ff_imdct_calc_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute inverse MDCT of size N = 2^nbits.
void	ff_imdct_half_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute the middle half of the inverse MDCT of size N = 2^nbits, thus excluding the parts that can be derived by symmetry.
void	ff_mdct_calc_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute MDCT of size N = 2^nbits.

---

Define Documentation

#define BF	(	x,
		y,
		a,
		b		)

Value:

do {                     \
        x = (a - b) >> 1;                       \
        y = (a + b) >> 1;                       \
    } while (0)

Definition at line 49 of file fft-internal.h.

#define CMUL	(	dre,
		dim,
		are,
		aim,
		bre,
		bim		)	CMULS(dre, dim, are, aim, bre, bim, 15)

Definition at line 59 of file fft-internal.h.

Referenced by ff_imdct_half_c(), ff_mdct_calc_c(), and ff_mdct_calcw_c().

#define CMULL	(	dre,
		dim,
		are,
		aim,
		bre,
		bim		)	CMULS(dre, dim, are, aim, bre, bim, 0)

Definition at line 62 of file fft-internal.h.

Referenced by ff_mdct_calcw_c().

#define CMULS	(	dre,
		dim,
		are,
		aim,
		bre,
		bim,
		sh		)

Value:

do {            \
        (dre) = (MUL16(are, bre) - MUL16(aim, bim)) >> sh;      \
        (dim) = (MUL16(are, bim) + MUL16(aim, bre)) >> sh;      \
    } while (0)

Definition at line 54 of file fft-internal.h.

#define ff_imdct_calc_c   FFT_NAME(ff_imdct_calc_c)

Definition at line 67 of file fft-internal.h.

Referenced by ff_fft_init().

#define ff_imdct_half_c   FFT_NAME(ff_imdct_half_c)

Definition at line 68 of file fft-internal.h.

Referenced by ff_fft_init(), and ff_imdct_calc_c().

#define ff_mdct_calc_c   FFT_NAME(ff_mdct_calc_c)

Definition at line 69 of file fft-internal.h.

Referenced by ff_fft_init().

#define FIX15

(

a

)

av_clip(SCALE_FLOAT(a, 15), -32767, 32767)

Definition at line 45 of file fft-internal.h.

Referenced by ff_init_ff_cos_tabs(), and ff_mdct_init().

#define SCALE_FLOAT	(	a,
		bits		)	lrint((a) * (double)(1 << (bits)))

Definition at line 44 of file fft-internal.h.

#define sqrthalf   ((int16_t)((1<<15)*M_SQRT1_2))

Definition at line 47 of file fft-internal.h.

Referenced by fft16(), and fft8().

---

Function Documentation

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

Compute inverse MDCT of size N = 2^nbits.

Parameters:

	output	N samples
	input	N/2 samples

Definition at line 137 of file mdct.c.

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

Compute the middle half of the inverse MDCT of size N = 2^nbits, thus excluding the parts that can be derived by symmetry.

Parameters:

	output	N/2 samples
	input	N/2 samples

Definition at line 95 of file mdct.c.

void ff_mdct_calc_c	(	FFTContext *	s,
		FFTSample *	out,
		const FFTSample *	input
	)

Compute MDCT of size N = 2^nbits.

Parameters:

	input	N samples
	out	N/2 samples

Definition at line 157 of file mdct.c.

void ff_mdct_calcw_c	(	FFTContext *	s,
		FFTDouble *	output,
		const FFTSample *	input
	)

Definition at line 23 of file mdct_fixed.c.

Referenced by ff_fft_init().