WPCSILENCE - routines for in memory silence en/decoding

codeSilence	encode the silence pieces of a stream 
codeDesilence	decode the silence encoded stream

Function Prototypes:
void codeSilence (void *inb, void *outb)
void codeDesilence ( void *inb, void *outb)

codeSilence:
Input:
inb	input buffer
Output:
outb	output buffer

codeDesilence:
Input:
inb	input buffer
Output:
outb	output buffer

codeSilence:
Note:
To avoid the inefficiency in encoding isolated 0's, I start a run
only when there are CODESTARTTHRSHOLD consective 0's. Therefore, 
a look ahead buffer is needed. The run is stopped as soon as there
is a non-0 symbol.  
Author: CWP: Tong Chen, 1994