supporting rare overflow mess even with error_resilience>=0

Originally committed as revision 839 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/msmpeg4.c

@@ -1859,7 +1859,7 @@ static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
         if (i > 62){
             i-= 192;
             if(i&(~63)){
-                if(s->error_resilience<0){
+                if((i+192 == 64 && level/qmul==-1) || s->error_resilience<0){
                     fprintf(stderr, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
                     break;
                 }else{