Remove vestiges of radix-2 FFT

Patch (mostly) by Loren Merritt

Originally committed as revision 23957 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 5 insertions, 77 deletions

diff --git a/libavcodec/fft.c b/libavcodec/fft.c
index bf240bf5c1..821665b08d 100644
--- a/libavcodec/fft.c
+++ b/libavcodec/fft.c
@@ -80,26 +80,21 @@ av_cold void ff_init_ff_cos_tabs(int index)
 
 av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
 {
-    int i, j, m, n;
-    float alpha, c1, s1, s2;
-    int av_unused has_vectors;
+    int i, j, n;
 
     if (nbits < 2 || nbits > 16)
         goto fail;
     s->nbits = nbits;
     n = 1 << nbits;
 
-    s->tmp_buf = NULL;
-    s->exptab  = av_malloc((n / 2) * sizeof(FFTComplex));
-    if (!s->exptab)
-        goto fail;
     s->revtab = av_malloc(n * sizeof(uint16_t));
     if (!s->revtab)
         goto fail;
+    s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
+    if (!s->tmp_buf)
+        goto fail;
     s->inverse = inverse;
 
-    s2 = inverse ? 1.0 : -1.0;
-
     s->fft_permute = ff_fft_permute_c;
     s->fft_calc    = ff_fft_calc_c;
 #if CONFIG_MDCT
@@ -107,104 +102,37 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse)
     s->imdct_half  = ff_imdct_half_c;
     s->mdct_calc   = ff_mdct_calc_c;
 #endif
-    s->exptab1     = NULL;
-    s->split_radix = 1;
 
     if (ARCH_ARM)     ff_fft_init_arm(s);
     if (HAVE_ALTIVEC) ff_fft_init_altivec(s);
     if (HAVE_MMX)     ff_fft_init_mmx(s);
 
-    if (s->split_radix) {
         for(j=4; j<=nbits; j++) {
             ff_init_ff_cos_tabs(j);
         }
         for(i=0; i<n; i++)
             s->revtab[-split_radix_permutation(i, n, s->inverse) & (n-1)] = i;
-        s->tmp_buf = av_malloc(n * sizeof(FFTComplex));
-    } else {
-        int np, nblocks, np2, l;
-        FFTComplex *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 = av_malloc(np * 2 * sizeof(FFTComplex));
-        if (!s->exptab1)
-            goto fail;
-        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);
-        av_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;
-        }
-    }
 
     return 0;
  fail:
     av_freep(&s->revtab);
-    av_freep(&s->exptab);
-    av_freep(&s->exptab1);
     av_freep(&s->tmp_buf);
     return -1;
 }
 
 void ff_fft_permute_c(FFTContext *s, FFTComplex *z)
 {
-    int j, k, np;
-    FFTComplex tmp;
+    int j, np;
     const uint16_t *revtab = s->revtab;
     np = 1 << s->nbits;
-
-    if (s->tmp_buf) {
         /* TODO: handle split-radix permute in a more optimal way, probably in-place */
         for(j=0;j<np;j++) s->tmp_buf[revtab[j]] = z[j];
         memcpy(z, s->tmp_buf, np * sizeof(FFTComplex));
-        return;
-    }
-
-    /* reverse */
-    for(j=0;j<np;j++) {
-        k = revtab[j];
-        if (k < j) {
-            tmp = z[k];
-            z[k] = z[j];
-            z[j] = tmp;
-        }
-    }
 }
 
 av_cold void ff_fft_end(FFTContext *s)
 {
     av_freep(&s->revtab);
-    av_freep(&s->exptab);
-    av_freep(&s->exptab1);
     av_freep(&s->tmp_buf);
 }