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

Typedefs

typedef float LPC_TYPE
 

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

#define ORDER_METHOD_EST   0
#define ORDER_METHOD_2LEVEL   1

Definition at line 31 of file lpc.h.

Referenced by dprint_compression_options(), and encode_residual_ch().

#define ORDER_METHOD_4LEVEL   2

Definition at line 32 of file lpc.h.

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

#define ORDER_METHOD_8LEVEL   3

Definition at line 33 of file lpc.h.

Referenced by dprint_compression_options(), and encode_residual_ch().

#define ORDER_METHOD_SEARCH   4

Definition at line 34 of file lpc.h.

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

#define ORDER_METHOD_LOG   5

Definition at line 35 of file lpc.h.

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

#define MIN_LPC_ORDER   1

Definition at line 37 of file lpc.h.

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

#define MAX_LPC_ORDER   32

Typedef Documentation

typedef float LPC_TYPE

Definition at line 124 of file lpc.h.

Enumeration Type Documentation

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

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_typeLPC method for determining coefficients, see FFLPCType for details

Definition at line 200 of file lpc.c.

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

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

Definition at line 159 of file lpc.c.

Referenced by cng_encode_frame().

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

Definition at line 171 of file lpc.c.

Referenced by ff_aac_search_for_tns().

int ff_lpc_init ( LPCContext s,
int  blocksize,
int  max_order,
enum FFLPCType  lpc_type 
)
void ff_lpc_init_x86 ( LPCContext s)

Definition at line 152 of file lpc.c.

Referenced by ff_lpc_init().

void ff_lpc_end ( LPCContext s)
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 132 of file lpc.h.

Referenced by ff_lpc_calc_ref_coefs(), and ff_lpc_calc_ref_coefs_f().

static int AAC_RENAME() 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 163 of file lpc.h.

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