resample2.c File Reference

audio resampling More...

#include "libavutil/avassert.h"
#include "avcodec.h"
#include "libavutil/common.h"

Go to the source code of this file.

Data Structures
struct	AVResampleContext

Macros
#define	FILTER_SHIFT   15
#define	FELEM   int16_t
#define	FELEM2   int32_t
#define	FELEML   int64_t
#define	FELEM_MAX   INT16_MAX
#define	FELEM_MIN   INT16_MIN
#define	WINDOW_TYPE   9

Functions
static double	bessel (double x)
	0th order modified bessel function of the first kind.
static int	build_filter (FELEM *filter, double factor, int tap_count, int phase_count, int scale, int type)
	Build a polyphase filterbank.
AVResampleContext *	av_resample_init (int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff)
	Initialize an audio resampler.
void	av_resample_close (AVResampleContext *c)
void	av_resample_compensate (AVResampleContext *c, int sample_delta, int compensation_distance)
	Compensate samplerate/timestamp drift.
int	av_resample (AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx)
	Resample an array of samples using a previously configured context.

Detailed Description

audio resampling

Author

Michael Niedermayer micha.nosp@m.elni.nosp@m.@gmx..nosp@m.at

Definition in file resample2.c.

Macro Definition Documentation

#define FILTER_SHIFT   15

Definition at line 35 of file resample2.c.

Referenced by av_resample(), av_resample_init(), build_filter(), and swri_resample_TMPL().

#define FELEM   int16_t

Definition at line 37 of file resample2.c.

Referenced by av_resample(), av_resample_init(), and swri_resample_TMPL().

#define FELEM2   int32_t

Definition at line 38 of file resample2.c.

Referenced by av_resample(), and swri_resample_TMPL().

#define FELEML   int64_t

Definition at line 39 of file resample2.c.

Referenced by av_resample(), and swri_resample_TMPL().

#define FELEM_MAX   INT16_MAX

Definition at line 40 of file resample2.c.

Referenced by build_filter().

#define FELEM_MIN   INT16_MIN

Definition at line 41 of file resample2.c.

Referenced by build_filter().

#define WINDOW_TYPE   9

Definition at line 42 of file resample2.c.

Referenced by av_resample_init().

Function Documentation

static double bessel ( double  x )

static

0th order modified bessel function of the first kind.

Definition at line 80 of file resample2.c.

Referenced by build_filter(), and ff_kbd_window_init().

static int build_filter ( FELEM *  filter, double  factor, int  tap_count, int  phase_count, int  scale, int  type  )

static

Build a polyphase filterbank.

Parameters

factor	resampling factor
scale	wanted sum of coefficients for each filter
type	0->cubic, 1->blackman nuttall windowed sinc, 2..16->kaiser windowed sinc beta=2..16

Returns

0 on success, negative on error

Definition at line 102 of file resample2.c.

Referenced by av_resample_init().