shithub: opus

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Adding a safeguard against unstable LPC, so now there's no way (that I can
think of) to produce NaNs in the new PLC.

--- a/libcelt/celt.c

+++ b/libcelt/celt.c

@@ -1347,13 +1347,20 @@

       iir(e, st->lpc, e, len+st->mode->overlap, LPC_ORDER, mem);

       {

-         float ratio, S2=0;

+         float S2=0;

          for (i=0;i<len+overlap;i++)

             S2 += e[i]*1.*e[i];

-         ratio = sqrt((S1+1)/(S2+1));

-         if (ratio < 1)

+         /* This checks for an "explosion" in the synthesis (including NaNs) */

+         if (!(S1 > 0.2f*S2))

+         {

             for (i=0;i<len+overlap;i++)

+               e[i] = 0;

+         } else if (S1 < S2)

+         {

+            float ratio = sqrt((S1+1)/(S2+1));

+            for (i=0;i<len+overlap;i++)

                e[i] *= ratio;

+         }

       }

       for (i=0;i<MAX_PERIOD+st->mode->overlap-N;i++)