initial XvMC support

Originally committed as revision 2085 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/error_resilience.c

@@ -894,6 +894,10 @@ void ff_er_frame_end(MpegEncContext *s){
     }else
         guess_mv(s);
 
+#ifdef HAVE_XVMC
+    /* the filters below are not XvMC compatible, skip them */
+    if(s->avctx->xvmc_acceleration) goto ec_clean;
+#endif
     /* fill DC for inter blocks */
     for(mb_y=0; mb_y<s->mb_height; mb_y++){
         for(mb_x=0; mb_x<s->mb_width; mb_x++){
@@ -979,6 +983,7 @@ void ff_er_frame_end(MpegEncContext *s){
         v_block_filter(s, s->current_picture.data[2], s->mb_width  , s->mb_height  , s->uvlinesize, 0);
     }
 
+ec_clean:
     /* clean a few tables */
     for(i=0; i<s->mb_num; i++){
         const int mb_xy= s->mb_index2xy[i];