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/* test of shrtdct.c */
#include <math.h>
#include <stdio.h>
#define MAX(x,y) ((x) > (y) ? (x) : (y))
/* random number generator, 0 <= RND < 1 */
#define RND(p) ((*(p) = (*(p) * 7141 + 54773) % 259200) * (1.0 / 259200))
#define NMAX 16
int main()
{
void ddct8x8s(int isgn, double **a);
void ddct16x16s(int isgn, double **a);
void putdata2d(int n1, int n2, double **a);
double errorcheck2d(int n1, int n2, double scale, double **a);
double err;
int i;
double aarr[NMAX][NMAX], *a[NMAX], barr[NMAX][NMAX], *b[NMAX];
for (i = 0; i < NMAX; i++) a[i] = aarr[i];
for (i = 0; i < NMAX; i++) b[i] = barr[i];
/* check of 8x8 DCT */
putdata2d(8, 8, a);
ddct8x8s(-1, a);
ddct8x8s(1, a);
err = errorcheck2d(8, 8, 1.0, a);
printf("ddct8x8s err= %g\n", err);
/* check of 16x16 DCT */
putdata2d(16, 16, a);
ddct16x16s(-1, a);
ddct16x16s(1, a);
err = errorcheck2d(16, 16, 1.0, a);
printf("ddct16x16s err= %g\n", err);
return 0;
}
void putdata2d(int n1, int n2, double **a)
{
int j1, j2, seed = 0;
for (j1 = 0; j1 <= n1 - 1; j1++) {
for (j2 = 0; j2 <= n2 - 1; j2++) {
a[j1][j2] = RND(&seed);
}
}
}
double errorcheck2d(int n1, int n2, double scale, double **a)
{
int j1, j2, seed = 0;
double err = 0, e;
for (j1 = 0; j1 <= n1 - 1; j1++) {
for (j2 = 0; j2 <= n2 - 1; j2++) {
e = RND(&seed) - a[j1][j2] * scale;
err = MAX(err, fabs(e));
}
}
return err;
}
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