also autodetect xvid idct if bitexact is used

Originally committed as revision 4761 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h263dec.c

@@ -637,7 +637,7 @@ retry:
 #endif
 
 #if defined(HAVE_MMX) && defined(CONFIG_GPL)
-    if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & MM_MMX) && !(s->flags&CODEC_FLAG_BITEXACT)){
+    if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & MM_MMX)){
         avctx->idct_algo= FF_IDCT_XVIDMMX;
         avctx->coded_width= 0; // force reinit
 //        dsputil_init(&s->dsp, avctx);