From 73e718f38aff8c558e8c1a08ec063dbc5b4cb9c6 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Wed, 14 Oct 2009 21:17:28 +0200
Subject: [PATCH] simplify fft_init() due to split_radix is always 1.

---
 imdct.c | 71 +++++++++++----------------------------------------------
 1 file changed, 13 insertions(+), 58 deletions(-)

diff --git a/imdct.c b/imdct.c
index e2cfe034..89ee2dfb 100644
--- a/imdct.c
+++ b/imdct.c
@@ -327,9 +327,7 @@ void imdct(struct mdct_context *s, float *output, const float *input)
 
 static int fft_init(struct fft_context *s, int nbits, int inverse)
 {
-	int i, j, m, n;
-	float alpha, c1, s1, s2;
-	int split_radix = 1;
+	int i, j, n;
 
 	if (nbits < 2 || nbits > 16)
 		return -E_FFT_BAD_PARAMS;
@@ -341,64 +339,21 @@ static int fft_init(struct fft_context *s, int nbits, int inverse)
 	s->revtab = para_malloc(n * sizeof(uint16_t));
 	s->inverse = inverse;
 
-	s2 = inverse ? 1.0 : -1.0;
-
 	s->exptab1 = NULL;
 
-	if (split_radix) {
-		for (j = 4; j <= nbits; j++) {
-			int k = 1 << j;
-			double freq = 2 * M_PI / k;
-			fftsample_t *tab = ff_cos_tabs[j - 4];
-			for (i = 0; i <= k / 4; i++)
-				tab[i] = cos(i * freq);
-			for (i = 1; i < k / 4; i++)
-				tab[k / 2 - i] = tab[i];
-		}
-		for (i = 0; i < n; i++)
-			s->revtab[-split_radix_permutation(
-				i, n, s->inverse) & (n - 1)] = i;
-		s->tmp_buf = para_malloc(n * sizeof(struct fft_complex));
-	} else {
-		int np, nblocks, np2, l;
-		struct fft_complex *q;
-
-		for (i = 0; i < (n / 2); i++) {
-			alpha = 2 * M_PI * (float) i / (float) n;
-			c1 = cos(alpha);
-			s1 = sin(alpha) * s2;
-			s->exptab[i].re = c1;
-			s->exptab[i].im = s1;
-		}
-
-		np = 1 << nbits;
-		nblocks = np >> 3;
-		np2 = np >> 1;
-		s->exptab1 = para_malloc(np * 2 * sizeof(struct fft_complex));
-		q = s->exptab1;
-		do {
-			for (l = 0; l < np2; l += 2 * nblocks) {
-				*q++ = s->exptab[l];
-				*q++ = s->exptab[l + nblocks];
-
-				q->re = -s->exptab[l].im;
-				q->im = s->exptab[l].re;
-				q++;
-				q->re = -s->exptab[l + nblocks].im;
-				q->im = s->exptab[l + nblocks].re;
-				q++;
-			}
-			nblocks = nblocks >> 1;
-		} while (nblocks != 0);
-		freep(&s->exptab);
-		/* compute bit reverse table */
-		for (i = 0; i < n; i++) {
-			m = 0;
-			for (j = 0; j < nbits; j++)
-				m |= ((i >> j) & 1) << (nbits - j - 1);
-			s->revtab[i] = m;
-		}
+	for (j = 4; j <= nbits; j++) {
+		int k = 1 << j;
+		double freq = 2 * M_PI / k;
+		fftsample_t *tab = ff_cos_tabs[j - 4];
+		for (i = 0; i <= k / 4; i++)
+			tab[i] = cos(i * freq);
+		for (i = 1; i < k / 4; i++)
+			tab[k / 2 - i] = tab[i];
 	}
+	for (i = 0; i < n; i++)
+		s->revtab[-split_radix_permutation(
+			i, n, s->inverse) & (n - 1)] = i;
+	s->tmp_buf = para_malloc(n * sizeof(struct fft_complex));
 	return 0;
 }
 
-- 
2.39.2