rdft.c File Reference

(Inverse) Real Discrete Fourier Transforms. More...

#include <stdlib.h>
#include <math.h>
#include "libavutil/mathematics.h"
#include "rdft.h"

Go to the source code of this file.

Functions
	SINTABLE (16)
	SINTABLE (32)
	SINTABLE (64)
	SINTABLE (128)
	SINTABLE (256)
	SINTABLE (512)
	SINTABLE (1024)
	SINTABLE (2048)
	SINTABLE (4096)
	SINTABLE (8192)
	SINTABLE (16384)
	SINTABLE (32768)
	SINTABLE (65536)
static void	rdft_calc_c (RDFTContext *s, FFTSample *data)
	Map one real FFT into two parallel real even and odd FFTs. More...
av_cold int	ff_rdft_init (RDFTContext *s, int nbits, enum RDFTransformType trans)
	Set up a real FFT. More...
av_cold void	ff_rdft_end (RDFTContext *s)

Variables
static SINTABLE_CONST FFTSample *const	ff_sin_tabs []

Detailed Description

(Inverse) Real Discrete Fourier Transforms.

Definition in file rdft.c.

Function Documentation

SINTABLE

(

16

)

SINTABLE

(

32

)

SINTABLE

(

64

)

SINTABLE

(

128

)

SINTABLE

(

256

)

SINTABLE

(

512

)

SINTABLE

(

1024

)

SINTABLE

(

2048

)

SINTABLE

(

4096

)

SINTABLE

(

8192

)

SINTABLE

(

16384

)

SINTABLE

(

32768

)

SINTABLE

(

65536

)

static void rdft_calc_c ( RDFTContext *  s, FFTSample *  data  )

static

Map one real FFT into two parallel real even and odd FFTs.

Then interleave the two real FFTs into one complex FFT. Unmangle the results. ref: http://www.engineeringproductivitytools.com/stuff/T0001/PT10.HTM

Definition at line 57 of file rdft.c.

Referenced by ff_rdft_init().

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

Set up a real FFT.

Parameters

nbits	log2 of the length of the input array
trans	the type of transform

Definition at line 99 of file rdft.c.

Referenced by decode_init(), ff_dct_init(), main(), qdm2_decode_init(), and wmavoice_decode_init().

av_cold void ff_rdft_end

(

RDFTContext *

s

)

Definition at line 132 of file rdft.c.

Referenced by decode_end(), ff_dct_end(), main(), qdm2_decode_close(), and wmavoice_decode_end().

Variable Documentation

SINTABLE_CONST FFTSample* const ff_sin_tabs[]

static

Initial value:

= {
    NULL, NULL, NULL, NULL,
    ff_sin_16, ff_sin_32, ff_sin_64, ff_sin_128, ff_sin_256, ff_sin_512, ff_sin_1024,
    ff_sin_2048, ff_sin_4096, ff_sin_8192, ff_sin_16384, ff_sin_32768, ff_sin_65536,
}

Definition at line 47 of file rdft.c.

Referenced by ff_rdft_init().