avi plays in media player but not rin other programs... how is that possible?

I think i have a codec problem

I used matlab to spit out an avi which media player plays fine, but other programs do not. Other programs can read all sorts of other avis, so i guess it is a problem with the codec that matlab used which media player can deal with, but other programs cannot

how is this possible? i thought codecs work for the whole computer at once? How can I tell what codec is used with media player?

Are you using Media Player Classic (as opposed to Windows Media Player)? Windows Media Player can’t read incomplete AVI’s (it’s probably the only program that can’t). If you suspect this is a codec problem, feed the file into gspot (http://www.headbands.com/gspot). Also gspot will tell you if the AVI is incomplete.