adpcm.h

ADPCM 4:1 coder and decoder

/*
** adpcm.h - include file for adpcm coder.
**
** Version 1.0, 7-Jul-92.
*/

struct adpcm_state {
    short      valprev;        /* Previous output value */
    char       index;          /* Index into stepsize table */
};

void adpcm_coder (short [], char [], long, struct adpcm_state *);
void adpcm_decoder (char [], short [], int, struct adpcm_state *);