shithub: opus

--- a/celt/celt_encoder.c

+++ b/celt/celt_encoder.c

@@ -281,6 +281,9 @@

       /* High-pass filter: (1 - 2*z^-1 + z^-2) / (1 - z^-1 + .5*z^-2) */

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

+#ifndef FIXED_POINT

+         float mem00;

+#endif

          opus_val32 x,y;

          x = SHR32(in[i+c*len],SIG_SHIFT);

          y = ADD32(mem0, x);

@@ -288,8 +291,13 @@

          mem0 = mem1 + y - SHL32(x,1);

          mem1 = x - SHR32(y,1);

 #else

+         /* Original code:

          mem0 = mem1 + y - 2*x;

          mem1 = x - .5f*y;

+         Modified code to shorten dependency chains: */

+         mem00=mem0;

+         mem0 = mem0 - x + .5f*mem1;

+         mem1 =  x - mem00;

 #endif

          tmp[i] = SROUND16(y, 2);

          /*printf("%f ", tmp[i]);*/

@@ -322,10 +330,11 @@

 #ifdef FIXED_POINT

          /* FIXME: Use PSHR16() instead */

          tmp[i] = mem0 + PSHR32(x2-mem0,forward_shift);

+         mem0 = tmp[i];

 #else

-         tmp[i] = mem0 + MULT16_16_P15(forward_decay,x2-mem0);

+         mem0 = x2 + (1.f-forward_decay)*mem0;

+         tmp[i] = forward_decay*mem0;

 #endif

-         mem0 = tmp[i];

       mem0=0;

@@ -337,11 +346,13 @@

 #ifdef FIXED_POINT

          /* FIXME: Use PSHR16() instead */

          tmp[i] = mem0 + PSHR32(tmp[i]-mem0,3);

-#else

-         tmp[i] = mem0 + MULT16_16_P15(QCONST16(0.125f,15),tmp[i]-mem0);

-#endif

          mem0 = tmp[i];

          maxE = MAX16(maxE, mem0);

+#else

+         mem0 = tmp[i] + 0.875f*mem0;

+         tmp[i] = 0.125f*mem0;

+         maxE = MAX16(maxE, 0.125f*mem0);

+#endif

       /*for (i=0;i<len2;i++)printf("%f ", tmp[i]/mean);printf("\n");*/

--

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