special handling for vp3 idct, use the c reference

Originally committed as revision 10105 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/bfin/dsputil_bfin.c

@@ -280,9 +280,11 @@ void dsputil_init_bfin( DSPContext* c, AVCodecContext *avctx )
 
     c->idct_permutation_type = FF_NO_IDCT_PERM;
     c->fdct                  = ff_bfin_fdct;
+    if (avctx->idct_algo!=FF_IDCT_VP3) {
         c->idct               = ff_bfin_idct;
         c->idct_add           = bfin_idct_add;
         c->idct_put           = bfin_idct_put;
+    }
 }