adpcm.h

在philips公司的ARM7芯片2136上实现ADPCM编码的原代码

/***********************************************************
Copyright 1992 by Stichting Mathematisch Centrum, Amsterdam, The
Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permission.
******************************************************************/

/*
**  ======== adpcm.h ========
**
**  Header file for adpcm.c
**
** Version 1.2, 18-Dec-92.
**
*/
#include "config.h"
 
#ifndef ADPCM_H
#define ADPCM_H

typedef struct  
{ 
  int16  valprev_L;	    /* Previous output value */
  int16  valprev_R;
  int16  index_L;
  int16  index_R;       /* Index into stepsize table */
}adpcm_state;

extern void Adpcm_Encoder(int16 *indata, int8 *outdata, int16 len, adpcm_state *state);
extern void Adpcm_Decoder(int8 *indata, int16 *outdata, int16 len, adpcm_state *state);

#endif