Signal Processing Library

Program name: wcepstra

Language: C

In file: parameter_lib.c

Objective: Calculate the Weighted Cepstral Coefficients from the Cepstral vectors

Usage: void weighted_cepstral(double ccep[], double ccepp[], int order, int type);

Parameters:

• ccep - The Cepstral Coefficients vector for the window of input data
• ccepp - The output array to put the calculated data
• order - The order
• type - The type of weighting system
  • 1 - no change
  • 2 - multiply by n
  • 3 - multiply by (1.0+((L/2.0)*sin(PI*(double)(n+1)/L)))

• void

Mathematical Description:

Comments:

User Comments

Code:

void weighted_cepstral(double ccep[], double ccepp[], int order, int type)
{
        int n;
        double aux, L;

        for(n = 0; n <= order; n++) {
                ccepp[n]=0.0;
        }

        L = (double) order;

        switch (type) {
        case 1:
                for(n = 0; n <= order; n++) {
                        ccepp[n] = ccep[n];
                }
                break;
        case 2:
                for(n = 0; n <= order; n++) {
                        ccepp[n] = ccep[n] * n;
                }
                break;
        case 3:
                for(n = 0; n <= order; n++) {
                        aux = PI*(double)(n+1)/L;
                        ccepp[n] = ccep[n] * (1.0+((L/2.0)*sin(aux)));
                }
                break;
        default:
                fprintf(stderr, "Weighted Cepstral type not within range(1-3)\n");
                exit(1);
                break;
        }
} /* End of the weighted cepstral function */