shithub: aacenc

--- a/libfaac/aacquant.c

+++ b/libfaac/aacquant.c

@@ -17,7 +17,7 @@

  * 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: aacquant.c,v 1.18 2003/05/01 10:29:06 knik Exp $

+ * $Id: aacquant.c,v 1.19 2003/05/12 17:52:47 knik Exp $

*/

 #include <math.h>

@@ -362,18 +362,33 @@

                             double *xr, double *xmin, int quality)

   int sfb, start, end, l;

-  const double globalthr = 37.0 / (double)quality;

-  int last = cb_offset[num_cb];

+  const double globalthr = 31.1 / (double)quality;

+  int last = 0, lastsb = 0;

   double totnrg = 0.0;

   static const double minfix = 1.5;

-  for (l = 0; l < last; l++)

+  end = cb_offset[num_cb];

+  for (l = 0; l < end; l++)

+  {

+    if (xr[l])

+    {

+      last = l;

     totnrg += xr[l] * xr[l];

+    }

+  }

+  last++;

   totnrg /= last;

     for (sfb = 0; sfb < num_cb; sfb++)

+    if (last > cb_offset[sfb])

+      lastsb = sfb;

+  }

+  for (sfb = 0; sfb < num_cb; sfb++)

+  {

     double thr, tmp;

     double enrg = 0.0;

@@ -380,12 +395,18 @@

         start = cb_offset[sfb];

         end = cb_offset[sfb + 1];

+    if (sfb > lastsb)

+    {

+      xmin[sfb] = 0;

+      continue;

+    }

     for (l = start; l < end; l++)

       enrg += xr[l]*xr[l];

-    thr = pow((double)(end-start)*totnrg/enrg, 0.5*(num_cb-sfb)/num_cb + 0.0);

+    thr = pow((double)(end-start)*totnrg/enrg, 0.425*(lastsb-sfb)/lastsb + 0.075);

-    tmp = minfix * pow((double)(start + 400) / (double)last, 0.6);

+    tmp = minfix * (double)(start + 400) / (double)last;

     if (tmp < thr)

       thr = tmp;

@@ -415,23 +436,26 @@

       int sfac;

       double fac;

       int dist;

+      double sfacfix0 = 1.0, dist0 = 1e50;

+      double maxx;

-      if (!xmin[sb])

-        continue;

       start = coderInfo->sfb_offset[sb];

       end = coderInfo->sfb_offset[sb+1];

-      tmp = 0.0;

+      if (!xmin[sb])

+	goto nullsfb;

+      maxx = 0.0;

       for (i = start; i < end; i++)

-	if (xr_pow[i] > tmp)

-	  tmp = xr_pow[i];

+	if (xr_pow[i] > maxx)

+	  maxx = xr_pow[i];

-      //printf("band %d: tmp: %f\n", sb, tmp);

-      if (tmp < 10.0)

+      //printf("band %d: maxx: %f\n", sb, maxx);

+      if (maxx < 10.0)

+      nullsfb:

 	for (i = start; i < end; i++)

 	  xi[i] = 0;

 	coderInfo->scale_factor[sb] = 10;

@@ -438,10 +462,11 @@

 	continue;

-      sfacfix = 1.0 / tmp;

+      sfacfix = 1.0 / maxx;

       sfac = log(sfacfix) * log_ifqstep - 0.5;

       for (i = start; i < end; i++)

 	xr_pow[i] *= sfacfix;

+      maxx *= sfacfix;

       coderInfo->scale_factor[sb] = sfac;

       QuantizeBand(xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);

       //printf("\tsfac: %d\n", sfac);

@@ -462,10 +487,44 @@

       quantvol = sqrt(quantvol/(double)(end-start)) * (double)(end-start);

       //printf("\tdiffvol: %f, qvol: %f\n", diffvol, quantvol);

-      dist = (diffvol / quantvol) > xmin[sb];

-      fac = 0.0;

+      tmp = diffvol / quantvol;

       if (fabs(fixstep) > maxstep)

+	double dd = 0.5*(tmp / xmin[sb] - 1.0);

+	if (fabs(dd) < fabs(fixstep))

+	{

+	  fixstep = dd;

+	  if (fabs(fixstep) < maxstep)

+	    fixstep = maxstep * ((fixstep > 0) ? 1 : -1);

+	}

+      }

+      if (fixstep > 0)

+      {

+	if (tmp < dist0)

+	{

+	  dist0 = tmp;

+	  sfacfix0 = sfacfix;

+	}

+	else

+	{

+	  if (fixstep > .1)

+	    fixstep = .1;

+	}

+      }

+      else

+      {

+	dist0 = tmp;

+	sfacfix0 = sfacfix;

+      }

+      dist = (tmp > xmin[sb]);

+      fac = 0.0;

+      if (fabs(fixstep) >= maxstep)

+      {

 	if ((dist && (fixstep < 0))

 	    || (!dist && (fixstep > 0)))

@@ -481,10 +540,24 @@

       if (fac != 0.0)

+	if (maxx * fac >= IXMAX_VAL)

+	{

+	  // restore best noise

+	  fac = sfacfix0 / sfacfix;

+	  for (i = start; i < end; i++)

+	    xr_pow[i] *= fac;

+	  maxx *= fac;

+	  sfacfix *= fac;

+	  coderInfo->scale_factor[sb] = log(sfacfix) * log_ifqstep - 0.5;

+	  QuantizeBand(xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);

+	  continue;

+	}

 	if (coderInfo->scale_factor[sb] < -10)

 	  for (i = start; i < end; i++)

 	    xr_pow[i] *= fac;

+          maxx *= fac;

           sfacfix *= fac;

 	  coderInfo->scale_factor[sb] = log(sfacfix) * log_ifqstep - 0.5;

 	  QuantizeBand(xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);