media player problem

Hi guys. Why runnuing a MediaPlayer in netbeans it works (I see the video) and if I exec it from command line I have

C:\Documents and Settings\emanuele\player\src>java -classpath .;lib\ext\mp3plugin.jar;lib\ext\jmf.jar;lib\ext\fobs4jmf.jar MediaPlayer

here

file:/C:/Documents%20and%20Settings/emanuele/Documenti/uni.avi

Unable to handle format: MP42, 640x480, FrameRate=25.0, Length=921600 0 extram bytes

Unable to handle format: mpeglayer3, 44100.0 Hz, 0-bit, Stereo, Unsigned, 1596 3.0 frame rate, FrameSize=8 bits

Failed to realize: com.sun.media.PlaybackEngine@147c5fc

Error: Unable to realize com.sun.media.PlaybackEngine@147c5fc

how could I fix it?

thanks in advance,

[739 byte] By [emanuele.ga] at [2007-11-27 4:57:32]