1 files changed, 20 insertions, 17 deletions

diff --git a/libavcodec/dct.c b/libavcodec/dct.c
index 83cf1b4896..ef3cd50a79 100644
--- a/libavcodec/dct.c
+++ b/libavcodec/dct.c
@@ -180,33 +180,36 @@ av_cold int ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType inverse)
     int n = 1 << nbits;
     int i;
 
+    memset(s, 0, sizeof(*s));
+
     s->nbits    = nbits;
     s->inverse  = inverse;
 
-    ff_init_ff_cos_tabs(nbits+2);
+    if (inverse == DCT_II && nbits == 5) {
+        s->dct_calc = dct32_func;
+    } else {
+        ff_init_ff_cos_tabs(nbits+2);
 
-    s->costab = ff_cos_tabs[nbits+2];
+        s->costab = ff_cos_tabs[nbits+2];
 
-    s->csc2 = av_malloc(n/2 * sizeof(FFTSample));
+        s->csc2 = av_malloc(n/2 * sizeof(FFTSample));
 
-    if (ff_rdft_init(&s->rdft, nbits, inverse == DCT_III) < 0) {
-        av_free(s->csc2);
-        return -1;
-    }
+        if (ff_rdft_init(&s->rdft, nbits, inverse == DCT_III) < 0) {
+            av_free(s->csc2);
+            return -1;
+        }
 
-    for (i = 0; i < n/2; i++)
-        s->csc2[i] = 0.5 / sin((M_PI / (2*n) * (2*i + 1)));
+        for (i = 0; i < n/2; i++)
+            s->csc2[i] = 0.5 / sin((M_PI / (2*n) * (2*i + 1)));
 
-    switch(inverse) {
-    case DCT_I  : s->dct_calc = ff_dct_calc_I_c; break;
-    case DCT_II : s->dct_calc = ff_dct_calc_II_c ; break;
-    case DCT_III: s->dct_calc = ff_dct_calc_III_c; break;
-    case DST_I  : s->dct_calc = ff_dst_calc_I_c; break;
+        switch(inverse) {
+        case DCT_I  : s->dct_calc = ff_dct_calc_I_c; break;
+        case DCT_II : s->dct_calc = ff_dct_calc_II_c ; break;
+        case DCT_III: s->dct_calc = ff_dct_calc_III_c; break;
+        case DST_I  : s->dct_calc = ff_dst_calc_I_c; break;
+        }
     }
 
-    if (inverse == DCT_II && nbits == 5)
-        s->dct_calc = dct32_func;
-
     s->dct32 = dct32;
     if (HAVE_MMX)     ff_dct_init_mmx(s);