ref: 590ad03a7e3fa9f3479f4e408bee93712b8b89df
parent: a9c38d5675ecc54f371bf6d78991872ca0f53f81
author: knik <knik>
date: Wed Aug 7 14:10:39 EDT 2002
rsfft output was reversed i.e. high frequencies first
--- a/libfaac/fft.c
+++ b/libfaac/fft.c
@@ -16,7 +16,7 @@
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
- * $Id: fft.c,v 1.5 2001/06/08 18:01:09 menno Exp $
+ * $Id: fft.c,v 1.6 2002/08/07 18:10:39 knik Exp $
*/
#include <math.h>
@@ -417,6 +417,9 @@
void rsfft(double *x, int logm)
{+ int i;
+ int size;
+
/* Call recursive routine */
rsrec(x, logm);
@@ -423,5 +426,20 @@
/* Output array unshuffling using bit-reversed indices */
if (logm > 1) {BR_permute(x, logm);
+ }
+
+ size = 1 << (logm - 1);
+
+ for (i = 0; i < (size / 2); i++)
+ {+ double tmp;
+
+ tmp = 1 * x[i];
+ x[i] = 1 * x[size - 1 - i];
+ x[size - 1 - i] = tmp;
+
+ tmp = 1 * x[size + i];
+ x[size + i] = 1 * x[2*size - 1 - i];
+ x[2*size - 1 - i] = tmp;
}
}