lpc.c File Reference

#include <stdio.h>
#include <assert.h>
#include "private.h"
#include "gsm.h"
#include "proto.h"

Macros
#define	SCALE(n)
#define	STEP(k)
#define	NEXTI   sl = *++sp
#define	STEP(A, B, MAC, MIC)

Functions
static void Autocorrelation	P2 ((s, L_ACF), word *s, longword *L_ACF)
static void Reflection_coefficients	P2 ((L_ACF, r), longword *L_ACF, register word *r)
static void Transformation_to_Log_Area_Ratios	P1 ((r), register word *r)
static void Quantization_and_coding	P1 ((LAR), register word *LAR)
void Gsm_LPC_Analysis	P3 ((S, s, LARc), struct gsm_state *S, word *s, word *LARc)

Macro Definition Documentation

NEXTI

#define NEXTI   sl = *++sp

SCALE

#define SCALE

(

n

)

Value:

case n: for (k = 0; k <= 159; k++) \
                float_s[k] = (float)    \
                        (s[k] = GSM_MULT_R(s[k], 16384 >> (n-1)));\
        break;

STEP [1/2]

#define STEP	(		A,
			B,
			MAC,
			MIC )

Value:

temp = GSM_MULT( A,   *LAR );   \
temp = GSM_ADD(  temp,   B );   \
temp = GSM_ADD(  temp, 256 );   \
temp = SASR(     temp,   9 );   \
*LAR  =  temp>MAC ? MAC - MIC : (temp<MIC ? 0 : temp - MIC); \
LAR++;

STEP [2/2]

#define STEP

(

k

)

Value:

L_ACF[k] += (longword)(sl * sp[ -(k) ]);

Function Documentation

P1() [1/2]

void Quantization_and_coding P1 ( (LAR) , register word * LAR )

static

P1() [2/2]

void Transformation_to_Log_Area_Ratios P1 ( (r) , register word * r )

static

P2() [1/2]

void Reflection_coefficients P2 ( (L_ACF, r) , longword * L_ACF, register word * r )

static

P2() [2/2]

void Fast_Autocorrelation P2 ( (s, L_ACF) , word * s, longword * L_ACF )

static

P3()

void Gsm_LPC_Analysis P3	(	(S, s, LARc)	,
		struct gsm_state *	S,
		word *	s,
		word *	LARc )