From c8f62a4aedc1e6fd6ab3091f95df301f38d1488b Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Tue, 31 Dec 2013 00:00:37 -0500
Subject: [PATCH] Improving the accuracy of the fixed-point radix-3 and radix-5
---
celt/kiss_fft.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/celt/kiss_fft.c b/celt/kiss_fft.c
index 79df7ee1e..a7bdde818 100644
--- a/celt/kiss_fft.c
+++ b/celt/kiss_fft.c
@@ -167,7 +167,12 @@ static void kf_bfly3(
kiss_twiddle_cpx epi3;
kiss_fft_cpx * Fout_beg = Fout;
+#ifdef FIXED_POINT
+ epi3.r = -16384;
+ epi3.i = -28378;
+#else
epi3 = st->twiddles[fstride*m];
+#endif
for (i=0;i<N;i++)
{
Fout = Fout_beg + i*mm;
@@ -215,13 +220,19 @@ static void kf_bfly5(
kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
int i, u;
kiss_fft_cpx scratch[13];
- const kiss_twiddle_cpx * twiddles = st->twiddles;
const kiss_twiddle_cpx *tw;
kiss_twiddle_cpx ya,yb;
kiss_fft_cpx * Fout_beg = Fout;
- ya = twiddles[fstride*m];
- yb = twiddles[fstride*2*m];
+#ifdef FIXED_POINT
+ ya.r = 10126;
+ ya.i = -31164;
+ yb.r = -26510;
+ yb.i = -19261;
+#else
+ ya = st->twiddles[fstride*m];
+ yb = st->twiddles[fstride*2*m];
+#endif
tw=st->twiddles;
for (i=0;i<N;i++)
--
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