shithub: opus

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ref: c544b1238cf4f07b02f8f30ea761f41c1389a594
parent: 72d89fd7f93e9ac6d1fbd4aac762a959217b6230
author: Jean-Marc Valin <[email protected]>
date: Sun Jul 24 18:06:08 EDT 2016 

Fixes an overflow in amp2Log2() for very large encoder input


--- a/celt/quant_bands.c
+++ b/celt/quant_bands.c
@@ -548,9 +548,15 @@
    c=0;
    do {
       for (i=0;i<effEnd;i++)
+      {
          bandLogE[i+c*m->nbEBands] =
-               celt_log2(SHL32(bandE[i+c*m->nbEBands],2))
+               celt_log2(bandE[i+c*m->nbEBands])
                - SHL16((opus_val16)eMeans[i],6);
+#ifdef FIXED_POINT
+         /* Compensate for bandLogE[] being Q12 but celt_log2() taking a Q14 input. */
+         bandLogE[i+c*m->nbEBands] += QCONST16(2.f, DB_SHIFT);
+#endif
+      }
       for (i=effEnd;i<end;i++)
          bandLogE[c*m->nbEBands+i] = -QCONST16(14.f,DB_SHIFT);
    } while (++c < C);