libswresample/resample.c File Reference

audio resampling More...

#include "libavutil/log.h"
#include "swresample_internal.h"

Go to the source code of this file.

Data Structures
struct	ResampleContext
Defines
#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)
	builds a polyphase filterbank.
ResampleContext *	swri_resample_init (ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff)
void	swri_resample_free (ResampleContext **c)
int	swr_set_compensation (struct SwrContext *s, int sample_delta, int compensation_distance)
	Activate resampling compensation.
int	swri_resample (ResampleContext *c, int16_t *dst, const int16_t *src, int *consumed, int src_size, int dst_size, int update_ctx)
int	swri_multiple_resample (ResampleContext *c, AudioData *dst, int dst_size, AudioData *src, int src_size, int *consumed)

---

Detailed Description

audio resampling

Author:

Michael Niedermayer <michaelni@gmx.at>

Definition in file resample.c.

---

Define Documentation

#define FELEM   int16_t

Definition at line 34 of file resample.c.

#define FELEM2   int32_t

Definition at line 35 of file resample.c.

#define FELEM_MAX   INT16_MAX

Definition at line 37 of file resample.c.

#define FELEM_MIN   INT16_MIN

Definition at line 38 of file resample.c.

#define FELEML   int64_t

Definition at line 36 of file resample.c.

#define FILTER_SHIFT   15

Definition at line 32 of file resample.c.

#define WINDOW_TYPE   9

Definition at line 39 of file resample.c.

---

Function Documentation

static double bessel

(

double

x

)

[static]

0th order modified bessel function of the first kind.

Definition at line 78 of file resample.c.

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

builds 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 112 of file resample.c.

int swr_set_compensation	(	struct SwrContext *	s,
		int	sample_delta,
		int	compensation_distance
	)

Activate resampling compensation.

Definition at line 248 of file resample.c.

Referenced by audio_decode_frame(), and do_audio_out().

int swri_multiple_resample	(	ResampleContext *	c,
		AudioData *	dst,
		int	dst_size,
		AudioData *	src,
		int	src_size,
		int *	consumed
	)

Definition at line 360 of file resample.c.

Referenced by resample().

int swri_resample	(	ResampleContext *	c,
		int16_t *	dst,
		const int16_t *	src,
		int *	consumed,
		int	src_size,
		int	dst_size,
		int	update_ctx
	)

Definition at line 271 of file resample.c.

Referenced by swri_multiple_resample().

void swri_resample_free

(

ResampleContext **

c

)

Definition at line 241 of file resample.c.

Referenced by swr_free(), and swr_init().

ResampleContext* swri_resample_init	(	ResampleContext *	c,
		int	out_rate,
		int	in_rate,
		int	filter_size,
		int	phase_shift,
		int	linear,
		double	cutoff
	)			[read]

Definition at line 202 of file resample.c.

Referenced by swr_init().