I store playlists as m3u files, but sometimes I want to play it on an external device or send it over the network. The playlist references files using absolute paths, and they have various formats (wav, flac, mp3, ogg).

I would like to convert it into a single cue/flac, as if it were an album that I just ripped from CD (though it may be longer than 80min.) It would be acceptable to create a directory full of uniform flacs with appropriately adjusted metadata, again as if ripped from CD.

I would like to avoid writing intermediates to disk unnecessarily, and I would like to avoid GUI if possible, but the only hard requirement is that it run quickly (that is to say, faster than realtime.)