libavcodec/resample2.c File Reference

audio resampling More...

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

Go to the source code of this file.

Data Structures

struct  AVResampleContext

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)
 Build a polyphase filterbank.
AVResampleContextav_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 <michaelni@gmx.at>

Definition in file resample2.c.


Define Documentation

#define FELEM   int16_t

#define FELEM2   int32_t

Definition at line 37 of file resample2.c.

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

#define FELEM_MAX   INT16_MAX

Definition at line 39 of file resample2.c.

Referenced by build_filter().

#define FELEM_MIN   INT16_MIN

Definition at line 40 of file resample2.c.

Referenced by build_filter().

#define FELEML   int64_t

Definition at line 38 of file resample2.c.

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

#define FILTER_SHIFT   15

Definition at line 34 of file resample2.c.

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

#define WINDOW_TYPE   9

Definition at line 41 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 79 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 101 of file resample2.c.

Referenced by av_resample_init(), ff_audio_resample_init(), and swri_resample_init().


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