DCT1 - 1D Discreet Cosine Transform Routines

dctiv -  in-place IV-type DCT, whose inverse is just itself 
dct   -  in-place DCT 

Function Prototypes:
void dctiv(float *x, int n, float **c);
void dct(float *x, int n, float **c, int type);

dctiv:
Input:
x         array[] of the signal before and after transform
c         table used in the transform 
n         length of the signal

dct:
x         array[] of the signal before and after transform
n         length of the signal
c         table used in the transform 
type      0 for forward and 1 for inverse transform
Author:		Tong Chen, 03/16/95
Modifier:       Tong Chen, 06/01/95, use the pre-generated table