#include <stdint.h>
#include "libavutil/avassert.h"
#include "libavutil/lls.h"
#include "aac_defines.h"

Data Structures
struct	LPCContext

Macros
#define	ORDER_METHOD_EST 0

#define	ORDER_METHOD_2LEVEL 1

#define	ORDER_METHOD_4LEVEL 2

#define	ORDER_METHOD_8LEVEL 3

#define	ORDER_METHOD_SEARCH 4

#define	ORDER_METHOD_LOG 5

#define	MIN_LPC_ORDER 1

#define	MAX_LPC_ORDER 32

Typedefs
typedef float	LPC_TYPE

typedef float	LPC_TYPE_U

Enumerations
enum	FFLPCType { FF_LPC_TYPE_DEFAULT = -1, FF_LPC_TYPE_NONE = 0, FF_LPC_TYPE_FIXED = 1, FF_LPC_TYPE_LEVINSON = 2, FF_LPC_TYPE_CHOLESKY = 3, FF_LPC_TYPE_NB }
	LPC analysis type. More...

Functions
int	ff_lpc_calc_coefs (LPCContext s, const int32_t samples, int blocksize, int min_order, int max_order, int precision, int32_t coefs[][MAX_LPC_ORDER], int *shift, enum FFLPCType lpc_type, int lpc_passes, int omethod, int min_shift, int max_shift, int zero_shift)
	Calculate LPC coefficients for multiple orders. More...

int	ff_lpc_calc_ref_coefs (LPCContext s, const int32_t samples, int order, double *ref)

double	ff_lpc_calc_ref_coefs_f (LPCContext s, const float samples, int len, int order, double *ref)

int	ff_lpc_init (LPCContext *s, int blocksize, int max_order, enum FFLPCType lpc_type)
	Initialize LPCContext. More...

void	ff_lpc_init_x86 (LPCContext *s)

void	ff_lpc_end (LPCContext *s)
	Uninitialize LPCContext. More...

static void	compute_ref_coefs (const LPC_TYPE autoc, int max_order, LPC_TYPE ref, LPC_TYPE *error)
	Schur recursion. More...

static int AAC_RENAME()	compute_lpc_coefs (const LPC_TYPE autoc, int max_order, LPC_TYPE lpc, int lpc_stride, int fail, int normalize)
	Levinson-Durbin recursion. More...

Macro Definition Documentation

◆ ORDER_METHOD_EST

#define ORDER_METHOD_EST 0

Definition at line 30 of file lpc.h.

◆ ORDER_METHOD_2LEVEL

#define ORDER_METHOD_2LEVEL 1

Definition at line 31 of file lpc.h.

◆ ORDER_METHOD_4LEVEL

#define ORDER_METHOD_4LEVEL 2

Definition at line 32 of file lpc.h.

◆ ORDER_METHOD_8LEVEL

#define ORDER_METHOD_8LEVEL 3

Definition at line 33 of file lpc.h.

◆ ORDER_METHOD_SEARCH

#define ORDER_METHOD_SEARCH 4

Definition at line 34 of file lpc.h.

◆ ORDER_METHOD_LOG

#define ORDER_METHOD_LOG 5

Definition at line 35 of file lpc.h.

◆ MIN_LPC_ORDER

#define MIN_LPC_ORDER 1

Definition at line 37 of file lpc.h.

◆ MAX_LPC_ORDER

#define MAX_LPC_ORDER 32

Definition at line 38 of file lpc.h.

Typedef Documentation

◆ LPC_TYPE

typedef float LPC_TYPE

Definition at line 126 of file lpc.h.

◆ LPC_TYPE_U

typedef float LPC_TYPE_U

Definition at line 127 of file lpc.h.

Enumeration Type Documentation

◆ FFLPCType

enum FFLPCType

LPC analysis type.

Enumerator
FF_LPC_TYPE_DEFAULT	use the codec default LPC type
FF_LPC_TYPE_NONE	do not use LPC prediction or use all zero coefficients
FF_LPC_TYPE_FIXED	fixed LPC coefficients
FF_LPC_TYPE_LEVINSON	Levinson-Durbin recursion.
FF_LPC_TYPE_CHOLESKY	Cholesky factorization.
FF_LPC_TYPE_NB	Not part of ABI.

Definition at line 43 of file lpc.h.

Function Documentation

◆ ff_lpc_calc_coefs()

int ff_lpc_calc_coefs	(	LPCContext *	s,
		const int32_t *	samples,
		int	blocksize,
		int	min_order,
		int	max_order,
		int	precision,
		int32_t	coefs[][MAX_LPC_ORDER],
		int *	shift,
		enum FFLPCType	lpc_type,
		int	lpc_passes,
		int	omethod,
		int	min_shift,
		int	max_shift,
		int	zero_shift
	)

Calculate LPC coefficients for multiple orders.

Parameters

lpc_type LPC method for determining coefficients, see FFLPCType for details

Definition at line 201 of file lpc.c.

Referenced by calc_predictor_params(), encode_residual_ch(), ra144_encode_frame(), and set_filter_params().

◆ ff_lpc_calc_ref_coefs()

int ff_lpc_calc_ref_coefs	(	LPCContext *	s,
		const int32_t *	samples,
		int	order,
		double *	ref
	)

Definition at line 160 of file lpc.c.

Referenced by cng_encode_frame().

◆ ff_lpc_calc_ref_coefs_f()

double ff_lpc_calc_ref_coefs_f	(	LPCContext *	s,
		const float *	samples,
		int	len,
		int	order,
		double *	ref
	)

Definition at line 172 of file lpc.c.

Referenced by ff_aac_search_for_tns().

◆ ff_lpc_init()

int ff_lpc_init	(	LPCContext *	s,
		int	blocksize,
		int	max_order,
		enum FFLPCType	lpc_type
	)

Initialize LPCContext.

Definition at line 301 of file lpc.c.

Referenced by aac_encode_init(), alac_encode_init(), cng_encode_init(), ff_lpc_calc_coefs(), flac_encode_init(), mlp_encode_init(), and ra144_encode_init().

◆ ff_lpc_init_x86()

void ff_lpc_init_x86 ( LPCContext * s )

Definition at line 152 of file lpc.c.

Referenced by ff_lpc_init().

◆ ff_lpc_end()

void ff_lpc_end ( LPCContext * s )

Uninitialize LPCContext.

Definition at line 323 of file lpc.c.

Referenced by aac_encode_end(), alac_encode_close(), cng_encode_close(), ff_lpc_calc_coefs(), flac_encode_close(), mlp_encode_close(), and ra144_encode_close().

◆ compute_ref_coefs()

static void compute_ref_coefs	(	const LPC_TYPE *	autoc,
		int	max_order,
		LPC_TYPE *	ref,
		LPC_TYPE *	error
	)

inlinestatic

Schur recursion.

Produces reflection coefficients from autocorrelation data.

Definition at line 135 of file lpc.h.

Referenced by ff_lpc_calc_ref_coefs(), and ff_lpc_calc_ref_coefs_f().

◆ compute_lpc_coefs()

static int AAC_RENAME() compute_lpc_coefs	(	const LPC_TYPE *	autoc,
		int	max_order,
		LPC_TYPE *	lpc,
		int	lpc_stride,
		int	fail,
		int	normalize
	)