Conversion of wpl files to mp4 file format

You generally cannot convert any multimedia playlist to actual multimedia file, simply because playlists just contain list of files and not the multimedia files. In this case wpl to mp4 conversion would represent conversion of Microsoft Windows Media Player playlists to MP4 file, which is not possible.

At best you can open the playlist using a text editor and check for the file paths to the actual multimedia files listed in it.

Open WPL file    Open MP4 file