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Improved PNS

--- a/libfaad/pns.c

+++ b/libfaad/pns.c

@@ -16,7 +16,7 @@

 ** along with this program; if not, write to the Free Software 

 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 **

-** $Id: pns.c,v 1.11 2002/08/26 18:41:47 menno Exp $

+** $Id: pns.c,v 1.12 2002/08/30 12:11:57 menno Exp $

 **/

 #include "common.h"

@@ -74,6 +74,7 @@

 static INLINE void gen_rand_vector(real_t *spec, uint16_t scale_factor, uint16_t size)

 {

     uint16_t i;

+    real_t energy = 0;

     /* 14496-3 says:

        scale = 1.0f/(size * (fftw_real)sqrt(MEAN_NRG));

@@ -80,11 +81,17 @@

     */

     float32_t scale = 1.0/(float32_t)sqrt(size * MEAN_NRG);

-    scale *= (float32_t)exp(LN2 * 0.25 * scale_factor);

-

     for (i = 0; i < size; i++)

     {

         spec[i] = REAL_CONST(scale*(float32_t)random2());

+        energy += MUL(spec[i],spec[i]);

+    }

+

+    scale = 1 / (float32_t)sqrt(energy);

+    scale *= (float32_t)pow(2.0, 0.25 * scale_factor);

+    for (i = 0; i < size; i++)

+    {

+        spec[i] = MUL(REAL_CONST(scale), spec[i]);

     }

 }