the in/out chunk define for 52M as:
#define INCHUNK    625
#define OUTCHUNK   625
this I can understand.

But the ones for 64M are defined as:
#define INRATE     (65*SAMPSPERSYM)
#define OUTRATE    (96)
#define INHISTORY  (INRATE*2)
#define OUTHISTORY (OUTRATE*2)
#define INCHUNK    (INRATE*9)
#define OUTCHUNK   (OUTRATE*9)

WHY the inrate is 65 and outrate is 96 and inchunk = inrate * 9 outchunk = outrate * 9? Can anybody explain this?

Thanks.