ref:http://www.real.com/linux
I found the newest version Realplayer for linux:RealPlayer 11 for Linux.
and I have extracted the codec files.
There are the newest rmvb decoder in it,maybe it can improve the
capability of playing rmvb.
But I don't know how to use it .

You can download the codecs from here:
http://www.myhtpc.com.cn/attachment.php?aid=2553
if anyone knows how to use it,please tell me.
Thank you.