Simplify: move division by constant off the loop

Originally committed as revision 15402 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/ra288.c

@@ -88,10 +88,11 @@ static void decode(RA288Context *ractx, float gain, int cb_coef)
     sum = av_clipf(sum, 0, 60);
 
     /* block 48 of G.728 spec */
-    sumsum = exp(sum * 0.1151292546497) * gain; /* pow(10.0,sum/20)*gain */
+    /* exp(sum * 0.1151292546497) == pow(10.0,sum/20) */
+    sumsum = exp(sum * 0.1151292546497) * gain / 2048.;
 
     for (i=0; i < 5; i++)
-        buffer[i] = codetable[cb_coef][i] * sumsum * (1./2048.);
+        buffer[i] = codetable[cb_coef][i] * sumsum;
 
     sum = scalar_product_float(buffer, buffer, 5) / 5;