rdft.c File Reference

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

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

Include dependency graph for rdft.c:

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	ff_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.

Function Documentation

static void ff_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

Referenced by ff_rdft_init().

av_cold void ff_rdft_end

(

RDFTContext *

s

)

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

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

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

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

)

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,
}

Referenced by ff_rdft_init().