ref: 06c67dbce2f214d58981ce4ed84bc2ec06d57bd8
parent: 5215623dcd5a26474239f6f817c153b7f3e02d73
author: Jean-Marc Valin <[email protected]>
date: Wed Feb 13 12:41:37 EST 2008
Simplified exp_spreading by unifying both directions. Have to admit I don't fully understand why that works!
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -43,47 +43,24 @@
int i, k;
float c, s;
c = cos(theta);
- s = sin(theta);
- if (dir > 0)
+ s = dir*sin(theta);
+ for (k=0;k<iter;k++)
{- for (k=0;k<iter;k++)
+ for (i=0;i<len-stride;i++)
{- for (i=0;i<len-stride;i++)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+stride];
- X[i] = c*x1 - s*x2;
- X[i+stride] = c*x2 + s*x1;
- }
- for (i=len-2*stride-1;i>=0;i--)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+stride];
- X[i] = c*x1 - s*x2;
- X[i+stride] = c*x2 + s*x1;
- }
+ float x1, x2;
+ x1 = X[i];
+ x2 = X[i+stride];
+ X[i] = c*x1 - s*x2;
+ X[i+stride] = c*x2 + s*x1;
}
- } else {- for (k=0;k<iter;k++)
+ for (i=len-2*stride-1;i>=0;i--)
{- for (i=0;i<len-2*stride;i++)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+stride];
- X[i] = c*x1 + s*x2;
- X[i+stride] = c*x2 - s*x1;
- }
- for (i=len-stride-1;i>=0;i--)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+stride];
- X[i] = c*x1 + s*x2;
- X[i+stride] = c*x2 - s*x1;
- }
+ float x1, x2;
+ x1 = X[i];
+ x2 = X[i+stride];
+ X[i] = c*x1 - s*x2;
+ X[i+stride] = c*x2 + s*x1;
}
}
}