How can mplayer play rmvb video file

[Barry]

Downloaded and extracted "all-20071007.tar.bz2" to /usr/lib/codec;

mkdir -p /usr/lib/codecs
tar -jxvf all-20071007.tar.bz2 --strip-components 1 -C /usr/lib/codecs/
(I can see some *.dll files and others under the /usr/lib/codecs/)
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Mplayer started and is play sound but no video, pop up error message 
showing;
Cannot find codec matching selected -vo and video format 0x30345652.
Wud appreciate some input