ref: 571e861dc31c602e826921ce6766f3b06d16c7e4
parent: 559e8ff602f172470b7f7faa37a1e531e83faf28
author: Jean-Marc Valin <[email protected]>
date: Sat Dec 29 19:06:10 EST 2007
more exp_rotation() cleanup
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -37,53 +37,56 @@
/* Applies a series of rotations so that pulses are spread like a two-sided
exponential */
-static void exp_rotation(float *X, int len, float theta, int dir)
+static void exp_rotation(float *X, int len, float theta, int dir, int stride, int iter)
{- int i, k, stride=2;
+ int i, k;
float c, s;
c = cos(theta);
s = sin(theta);
if (dir > 0)
{- for (i=0;i<len-2;i++)
+ for (k=0;k<iter;k++)
{- float x1, x2;
- x1 = X[i];
- x2 = X[i+2];
- X[i] = c*x1 - s*x2;
- X[i+2] = c*x2 + s*x1;
+ 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;
+ }
}
- for (i=len-5;i>=0;i--)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+2];
- X[i] = c*x1 - s*x2;
- X[i+2] = c*x2 + s*x1;
- }
-
} else {- for (i=0;i<len-4;i++)
+ for (k=0;k<iter;k++)
{- float x1, x2;
- x1 = X[i];
- x2 = X[i+2];
- X[i] = c*x1 + s*x2;
- X[i+2] = c*x2 - s*x1;
+ 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;
+ }
}
-
- for (i=len-3;i>=0;i--)
- {- float x1, x2;
- x1 = X[i];
- x2 = X[i+2];
- X[i] = c*x1 + s*x2;
- X[i+2] = c*x2 - s*x1;
- }
}
}
-
/* Compute the energy in each of the bands */
void compute_band_energies(const CELTMode *m, float *X, float *bank)
{@@ -264,7 +267,7 @@
{float theta;
theta = pow(.1f,1.f*abs(m->nbPulses[i])/(B*(eBands[i+1]-eBands[i])));
- exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, dir);
+ exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, dir, 2, 1);
}
//printf ("\n");}