imdct: Use the 1/sqrt(2) constant from math.h.

No need to define our own one.

diff --git a/imdct.c b/imdct.c
index ba5690b04e52bdd45ea2d433822d6e6da47fc19d..3495e61181b1074a5223955d6d66d90381436fbe 100644 (file)
--- a/imdct.c
+++ b/imdct.c
@@ -95,9 +95,6 @@ static int split_radix_permutation(int i, int n)
                return split_radix_permutation(i, m) * 4 - 1;
 }
 
-/** 1 / sqrt(2). */
-#define SQRTHALF (float)0.70710678118654752440
-
 #define BF(x, y, a, b) {\
        x = a - b;\
        y = a + b;\
@@ -209,7 +206,7 @@ static void fft8(struct fft_complex *z)
        BF(z[6].re, z[2].re, z[2].re, t7);
        BF(z[6].im, z[2].im, z[2].im, t8);
 
-       TRANSFORM(z[1], z[3], z[5], z[7], SQRTHALF, SQRTHALF);
+       TRANSFORM(z[1], z[3], z[5], z[7], M_SQRT1_2, M_SQRT1_2);
 }
 
 static void fft16(struct fft_complex *z)
@@ -221,7 +218,7 @@ static void fft16(struct fft_complex *z)
        fft4(z + 12);
 
        TRANSFORM_ZERO(z[0], z[4], z[8], z[12]);
-       TRANSFORM(z[2], z[6], z[10], z[14], SQRTHALF, SQRTHALF);
+       TRANSFORM(z[2], z[6], z[10], z[14], M_SQRT1_2, M_SQRT1_2);
        TRANSFORM(z[1], z[5], z[9], z[13], cos_16[1], cos_16[3]);
        TRANSFORM(z[3], z[7], z[11], z[15], cos_16[3], cos_16[1]);
 }