typedef struct g721_adpcmwaveformat_tag {
        WAVEFORMATEX    wfx;
        WORD            nAuxBlockSize;
} G721_ADPCMWAVEFORMAT;

typedef G721_ADPCMWAVEFORMAT *PG721_ADPCMWAVEFORMAT;

typedef G721_ADPCMWAVEFORMAT NEAR *NPG721_ADPCMWAVEFORMAT;

typedef G721_ADPCMWAVEFORMAT FAR  *LPG721_ADPCMWAVEFORMAT;