FFmpeg: libavcodec/lpc.h File Reference

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

Go to the source code of this file.

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

#define	LPC_TYPE float

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 max_shift, int zero_shift)
	Calculate LPC coefficients for multiple orders.

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

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

void	ff_lpc_init_x86 (LPCContext *s)

void	ff_lpc_end (LPCContext *s)
	Uninitialize LPCContext.

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

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

Macro Definition Documentation

#define ORDER_METHOD_EST 0

Definition at line 28 of file lpc.h.

Referenced by calc_predictor_params(), dprint_compression_options(), ff_lpc_calc_coefs(), flac_encode_init(), and ra144_encode_frame().

#define ORDER_METHOD_2LEVEL 1

Definition at line 29 of file lpc.h.

Referenced by dprint_compression_options(), and encode_residual_ch().

#define ORDER_METHOD_4LEVEL 2

Definition at line 30 of file lpc.h.

Referenced by dprint_compression_options(), encode_residual_ch(), and flac_encode_init().

#define ORDER_METHOD_8LEVEL 3

Definition at line 31 of file lpc.h.

Referenced by dprint_compression_options(), and encode_residual_ch().

#define ORDER_METHOD_SEARCH 4

Definition at line 32 of file lpc.h.

Referenced by dprint_compression_options(), encode_residual_ch(), and flac_encode_init().

#define ORDER_METHOD_LOG 5

Definition at line 33 of file lpc.h.

Referenced by dprint_compression_options(), encode_residual_ch(), and flac_encode_init().

#define MIN_LPC_ORDER 1

Definition at line 35 of file lpc.h.

Referenced by alac_encode_init(), ff_lpc_calc_coefs(), and flac_encode_init().

#define MAX_LPC_ORDER 32

Definition at line 36 of file lpc.h.

Referenced by calc_predictor_params(), compute_ref_coefs(), encode_residual_ch(), ff_lpc_calc_coefs(), ff_lpc_calc_ref_coefs(), flac_encode_init(), and ra144_encode_frame().

#define LPC_TYPE float

Definition at line 113 of file lpc.h.

Referenced by compute_lpc_coefs(), and compute_ref_coefs().

Enumeration Type Documentation

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 41 of file lpc.h.

Function Documentation

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	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 170 of file lpc.c.

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

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

Definition at line 152 of file lpc.c.

Referenced by cng_encode_frame().

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

Initialize LPCContext.

Definition at line 268 of file lpc.c.

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

void ff_lpc_init_x86 ( LPCContext * s )

Definition at line 148 of file lpc.c.

Referenced by ff_lpc_init().

void ff_lpc_end ( LPCContext * s )

Uninitialize LPCContext.

Definition at line 290 of file lpc.c.

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

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 120 of file lpc.h.

Referenced by ff_lpc_calc_ref_coefs().

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

inlinestatic

Levinson-Durbin recursion.

Produce LPC coefficients from autocorrelation data.

Definition at line 151 of file lpc.h.

Referenced by apply_tns(), backward_filter(), and ff_lpc_calc_coefs().