shithub: aacenc

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quantizer: calculate scalefactor first then band multiplier

--- a/libfaac/quantize.c

+++ b/libfaac/quantize.c

@@ -87,7 +87,7 @@

         target *= 0.45;

     }

-    target *= 6.5 / (1.0 + ((double)(start+end)/last));

+    target *= 8.0 / (1.0 + ((double)(start+end)/last));

     bandqual[sfb] = target * quality;

   }

@@ -114,7 +114,6 @@

       int sfac;

       double maxx;

       double rmsx;

-      double ein, eout;

       start = coderInfo->sfb_offset[sb];

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

@@ -140,27 +139,17 @@

           continue;

       }

-      ein = eout = 0;

-      sfacfix = bandqual[sb] / rmsx;

+      sfac = lrint(log(bandqual[sb] / rmsx) * sfstep);

+      sfacfix = exp(sfac / sfstep);

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

       {

           double tmp = fabs(xr[cnt]);

-          ein += tmp *tmp;

-

           tmp *= sfacfix;

           tmp = sqrt(tmp * sqrt(tmp));

           xi[cnt] = (int)(tmp + MAGIC_NUMBER);

-

-          tmp = pow43[xi[cnt]];

-          eout += tmp * tmp;

       }

-

-      if (eout < 1.0)

-          sfac = 10;

-      else

-          sfac = lrint(log(sqrt(eout / ein)) * sfstep);

       coderInfo->scale_factor[sb] = sfac;

     }