ref: 455b42743d3a3458f7c23926607e53c0b2906e5e
dir: /sys/src/cmd/audio/libvorbis/lpc.h/
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
* by the XIPHOPHORUS Company http://www.xiph.org/ *
* *
********************************************************************
function: LPC low level routines
last mod: $Id: lpc.h,v 1.19 2002/07/11 06:40:49 xiphmont Exp $
********************************************************************/
#ifndef _V_LPC_H_
#define _V_LPC_H_
#include "vorbis/codec.h"
#include "smallft.h"
typedef struct lpclook{
/* en/decode lookups */
drft_lookup fft;
int ln;
int m;
} lpc_lookup;
extern void lpc_init(lpc_lookup *l,long mapped, int m);
extern void lpc_clear(lpc_lookup *l);
/* simple linear scale LPC code */
extern float vorbis_lpc_from_data(float *data,float *lpc,int n,int m);
extern float vorbis_lpc_from_curve(float *curve,float *lpc,lpc_lookup *l);
extern void vorbis_lpc_predict(float *coeff,float *prime,int m,
float *data,long n);
#endif