I have recently been exploring new extraction methods to some success. Thus I am happy to say that I am now able to provide a new package (a ZIP file containing all 28 wc3 PSX midis without duplicates) to *replace* the old package. The files should be of similar quality, but here I also have extracted the names of the file used by the game internally. It should also be easier to find the specific piece you want to play.You can download the updated MIDI pack here (151 kb) and the MultiEx Commander script here.
I came in contact with the guys over at xentax.com and, when I detailed what I wanted to do, it was only a short while before they were able to provide a solution. I'm attaching a custom script for their MultiEx Commander program (a utility for exploring various game resource archive files). People who pay to register the program can use the script to extract any file from the *.LIB files - including all the movies and comm audio files - from the PSX versions of WC3 and WC4. So far, though, I have only had success in playing the MIDIs and have not yet come up with a solution for the movies and dialogue. I'm in the process of looking into the movie and audio file formats next.