aac.h File Reference

AAC definitions and structures. More...

#include "aac_defines.h"
#include "libavutil/float_dsp.h"
#include "libavutil/fixed_dsp.h"
#include "avcodec.h"
#include "mdct15.h"
#include "fft.h"
#include "mpeg4audio.h"
#include "sbr.h"
#include <stdint.h>

Go to the source code of this file.

Classes
struct	OutputConfiguration
struct	PredictorState
	Predictor State. More...
struct	LongTermPrediction
	Long Term Prediction. More...
struct	IndividualChannelStream
	Individual Channel Stream. More...
struct	TemporalNoiseShaping
	Temporal Noise Shaping. More...
struct	DynamicRangeControl
	Dynamic Range Control - decoded from the bitstream but not processed further. More...
struct	Pulse
struct	ChannelCoupling
	coupling parameters More...
struct	SingleChannelElement
	Single Channel Element - used for both SCE and LFE elements. More...
struct	ChannelElement
	channel element - generic struct for SCE/CPE/CCE/LFE More...
struct	AACContext
	main AAC context More...

Macros
#define	MAX_CHANNELS   64
#define	MAX_ELEM_ID   16
#define	TNS_MAX_ORDER   20
#define	MAX_LTP_LONG_SFB   40
#define	CLIP_AVOIDANCE_FACTOR   0.95f
#define	IS_CODEBOOK_UNSIGNED(x)   (((x) - 1) & 10)
#define	MAX_PREDICTORS   672
#define	SCALE_DIV_512   36
	scalefactor difference that corresponds to scale difference in 512 times
#define	SCALE_ONE_POS   140
	scalefactor index that corresponds to scale=1.0
#define	SCALE_MAX_POS   255
	scalefactor index maximum value
#define	SCALE_MAX_DIFF   60
	maximum scalefactor difference allowed by standard
#define	SCALE_DIFF_ZERO   60
	codebook index corresponding to zero scalefactor indices difference
#define	POW_SF2_ZERO   200
	ff_aac_pow2sf_tab index corresponding to pow(2, 0);
#define	NOISE_PRE   256
	preamble for NOISE_BT, put in bitstream with the first noise band
#define	NOISE_PRE_BITS   9
	length of preamble
#define	NOISE_OFFSET   90
	subtracted from global gain, used as offset for the preamble

Typedefs
typedef struct OutputConfiguration	OutputConfiguration
typedef struct PredictorState	PredictorState
	Predictor State.
typedef struct LongTermPrediction	LongTermPrediction
	Long Term Prediction.
typedef struct IndividualChannelStream	IndividualChannelStream
	Individual Channel Stream.
typedef struct TemporalNoiseShaping	TemporalNoiseShaping
	Temporal Noise Shaping.
typedef struct DynamicRangeControl	DynamicRangeControl
	Dynamic Range Control - decoded from the bitstream but not processed further.
typedef struct Pulse	Pulse
typedef struct ChannelCoupling	ChannelCoupling
	coupling parameters
typedef struct SingleChannelElement	SingleChannelElement
	Single Channel Element - used for both SCE and LFE elements.
typedef struct ChannelElement	ChannelElement
	channel element - generic struct for SCE/CPE/CCE/LFE

Enumerations
enum	RawDataBlockType {   TYPE_SCE, TYPE_CPE, TYPE_CCE, TYPE_LFE,   TYPE_DSE, TYPE_PCE, TYPE_FIL, TYPE_END }
enum	ExtensionPayloadID {   EXT_FILL, EXT_FILL_DATA, EXT_DATA_ELEMENT, EXT_DYNAMIC_RANGE = 0xb,   EXT_SBR_DATA = 0xd, EXT_SBR_DATA_CRC = 0xe }
enum	WindowSequence { ONLY_LONG_SEQUENCE, LONG_START_SEQUENCE, EIGHT_SHORT_SEQUENCE, LONG_STOP_SEQUENCE }
enum	BandType {   ZERO_BT = 0, FIRST_PAIR_BT = 5, ESC_BT = 11, RESERVED_BT = 12,   NOISE_BT = 13, INTENSITY_BT2 = 14, INTENSITY_BT = 15 }
enum	ChannelPosition {   AAC_CHANNEL_OFF = 0, AAC_CHANNEL_FRONT = 1, AAC_CHANNEL_SIDE = 2, AAC_CHANNEL_BACK = 3,   AAC_CHANNEL_LFE = 4, AAC_CHANNEL_CC = 5 }
enum	CouplingPoint { BEFORE_TNS, BETWEEN_TNS_AND_IMDCT, AFTER_IMDCT = 3 }
	The point during decoding at which channel coupling is applied.
enum	OCStatus {   OC_NONE, OC_TRIAL_PCE, OC_TRIAL_FRAME, OC_GLOBAL_HDR,   OC_LOCKED }
	Output configuration status. More...

Functions
void	ff_aacdec_init_mips (AACContext *c)

Detailed Description

AAC definitions and structures.

Author

Oded Shimon ( ods15 ods15 dyndns org )

Maxim Gavrilov ( maxim.gavrilov gmail com )

Enumeration Type Documentation

BandType

enum BandType

Enumerator
ZERO_BT	Scalefactors and spectral data are all zero.
FIRST_PAIR_BT	This and later band types encode two values (rather than four) with one code word.
ESC_BT	Spectral data are coded with an escape sequence.
RESERVED_BT	Band types following are encoded differently from others.
NOISE_BT	Spectral data are scaled white noise not coded in the bitstream.
INTENSITY_BT2	Scalefactor data are intensity stereo positions (out of phase).
INTENSITY_BT	Scalefactor data are intensity stereo positions (in phase).

OCStatus

enum OCStatus

Output configuration status.

Enumerator
OC_NONE	Output unconfigured.
OC_TRIAL_PCE	Output configuration under trial specified by an inband PCE.
OC_TRIAL_FRAME	Output configuration under trial specified by a frame header.
OC_GLOBAL_HDR	Output configuration set in a global header but not yet locked.
OC_LOCKED	Output configuration locked in place.