fixed a sig4 bug an non mmx2 cpus (in case of more sig4 errors please send me...

fixed a sig4 bug an non mmx2 cpus (in case of more sig4 errors please send me a "disassemble $eip-16 $eip+16" from gdb)

Originally committed as revision 2182 to svn://svn.mplayerhq.hu/mplayer/trunk/postproc