dither.c File Reference

Dithered Audio Sample Quantization. More...

#include <math.h>
#include <stdint.h>
#include "libavutil/attributes.h"
#include "libavutil/common.h"
#include "libavutil/lfg.h"
#include "libavutil/mem.h"
#include "libavutil/samplefmt.h"
#include "audio_convert.h"
#include "dither.h"
#include "internal.h"

Classes
struct	DitherState
struct	DitherContext

Macros
#define	MUTE_THRESHOLD_SEC   0.000333
#define	S16_SCALE   32753.0f
#define	LFG_SCALE   (1.0f / (2.0f * INT32_MAX))
#define	SQRT_1_6   0.40824829046386301723f

Typedefs
typedef struct DitherState	DitherState

Functions
int	ff_convert_dither (DitherContext *c, AudioData *dst, AudioData *src)
	Convert audio sample format with dithering. More...
void	ff_dither_free (DitherContext **cp)
	Free a DitherContext. More...
DitherContext *	ff_dither_alloc (AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map)
	Allocate and initialize a DitherContext. More...

Detailed Description

Dithered Audio Sample Quantization.

Converts from dbl, flt, or s32 to s16 using dithering.

Function Documentation

ff_convert_dither()

int ff_convert_dither	(	DitherContext *	c,
		AudioData *	dst,
		AudioData *	src
	)

Convert audio sample format with dithering.

Parameters

c	DitherContext
dst	destination audio data
src	source audio data

Returns

0 if ok, negative AVERROR code on failure

ff_dither_alloc()

DitherContext* ff_dither_alloc	(	AVAudioResampleContext *	avr,
		enum AVSampleFormat	out_fmt,
		enum AVSampleFormat	in_fmt,
		int	channels,
		int	sample_rate,
		int	apply_map
	)

Allocate and initialize a DitherContext.

The parameters in the AVAudioResampleContext are used to initialize the DitherContext.

Parameters

avr	AVAudioResampleContext

Returns

newly-allocated DitherContext

ff_dither_free()

void ff_dither_free

(

DitherContext **

c

)

Free a DitherContext.

Parameters

c	DitherContext