aacpsy.c File Reference

AAC encoder psychoacoustic model. More...

#include "libavutil/attributes.h"
#include "libavutil/ffmath.h"
#include "avcodec.h"
#include "aactab.h"
#include "psymodel.h"

Classes
struct	AacPsyBand
	information for single band used by 3GPP TS26.403-inspired psychoacoustic model More...
struct	AacPsyChannel
	single/pair channel context for psychoacoustic model More...
struct	AacPsyCoeffs
	psychoacoustic model frame type-dependent coefficients More...
struct	AacPsyContext
	3GPP TS26.403-inspired psychoacoustic model specific data More...
struct	PsyLamePreset
	LAME psy model preset struct. More...

Macros
#define	ATH_ADD   4

Typedefs
typedef struct AacPsyBand	AacPsyBand
	information for single band used by 3GPP TS26.403-inspired psychoacoustic model
typedef struct AacPsyChannel	AacPsyChannel
	single/pair channel context for psychoacoustic model
typedef struct AacPsyCoeffs	AacPsyCoeffs
	psychoacoustic model frame type-dependent coefficients
typedef struct AacPsyContext	AacPsyContext
	3GPP TS26.403-inspired psychoacoustic model specific data
typedef struct PsyLamePreset	PsyLamePreset
	LAME psy model preset struct.

Variables
const FFPsyModel	ff_aac_psy_model
#define	PSY_3GPP_THR_SPREAD_HI   1.5f
	constants for 3GPP AAC psychoacoustic model
#define	PSY_3GPP_THR_SPREAD_LOW   3.0f
#define	PSY_3GPP_EN_SPREAD_HI_L1   2.0f
#define	PSY_3GPP_EN_SPREAD_HI_L2   1.5f
#define	PSY_3GPP_EN_SPREAD_HI_S   1.5f
#define	PSY_3GPP_EN_SPREAD_LOW_L   3.0f
#define	PSY_3GPP_EN_SPREAD_LOW_S   2.0f
#define	PSY_3GPP_RPEMIN   0.01f
#define	PSY_3GPP_RPELEV   2.0f
#define	PSY_3GPP_C1   3.0f /* log2(8) */
#define	PSY_3GPP_C2   1.3219281f /* log2(2.5) */
#define	PSY_3GPP_C3   0.55935729f /* 1 - C2 / C1 */
#define	PSY_SNR_1DB   7.9432821e-1f /* -1dB */
#define	PSY_SNR_25DB   3.1622776e-3f /* -25dB */
#define	PSY_3GPP_SAVE_SLOPE_L   -0.46666667f
#define	PSY_3GPP_SAVE_SLOPE_S   -0.36363637f
#define	PSY_3GPP_SAVE_ADD_L   -0.84285712f
#define	PSY_3GPP_SAVE_ADD_S   -0.75f
#define	PSY_3GPP_SPEND_SLOPE_L   0.66666669f
#define	PSY_3GPP_SPEND_SLOPE_S   0.81818181f
#define	PSY_3GPP_SPEND_ADD_L   -0.35f
#define	PSY_3GPP_SPEND_ADD_S   -0.26111111f
#define	PSY_3GPP_CLIP_LO_L   0.2f
#define	PSY_3GPP_CLIP_LO_S   0.2f
#define	PSY_3GPP_CLIP_HI_L   0.95f
#define	PSY_3GPP_CLIP_HI_S   0.75f
#define	PSY_3GPP_AH_THR_LONG   0.5f
#define	PSY_3GPP_AH_THR_SHORT   0.63f
#define	PSY_PE_FORGET_SLOPE   511
#define	PSY_3GPP_BITS_TO_PE(bits)   ((bits) * 1.18f)
#define	PSY_3GPP_PE_TO_BITS(bits)   ((bits) / 1.18f)
#define	PSY_LAME_FIR_LEN   21
	LAME psy model FIR order.
#define	AAC_BLOCK_SIZE_LONG   1024
	long block size
#define	AAC_BLOCK_SIZE_SHORT   128
	short block size
#define	AAC_NUM_BLOCKS_SHORT   8
	number of blocks in a short sequence
#define	PSY_LAME_NUM_SUBBLOCKS   3
	Number of sub-blocks in each short block.
enum	{ PSY_3GPP_AH_NONE, PSY_3GPP_AH_INACTIVE, PSY_3GPP_AH_ACTIVE }

Detailed Description

AAC encoder psychoacoustic model.

Variable Documentation

ff_aac_psy_model

const FFPsyModel ff_aac_psy_model

Initial value:

=
{
    .name    = "3GPP TS 26.403-inspired model",
    .init    = psy_3gpp_init,
    .window  = psy_lame_window,
    .analyze = psy_3gpp_analyze,
    .end     = psy_3gpp_end,
}