If you're on an operating system higher than snow leopard (10.6), you'll probably have to delete a couple files from AVIdemux for it to operate properly. This link tells ya what to do- http://www.zerosignal.co.uk/2011/08/a... Right click the avidemux application, then Show Contents. Then delete libxml.2.dylib and libiconv.2.dylib located in Contents/Resources/lib folder. This will make Avidemux work with lion and after.