How to check for new/not linked *.mp3 in *.m3u playlist?

I organized all my music in such a way that I have an *.m3u playlist which should normally contain all *.mp3 songs from the current folder and all subfolders below. Simplified Example:

D:\music\ballads\ballads.m3u
contains .e.g.
D:\music\ballads\90ies\song1.mp3
D:\music\ballads\90ies\song1.mp3
...
D:\music\ballads\italian\song1.mp3
D:\music\ballads\italian\song2.mp3
...

Now it could happen that I accidentially rename one of the songs resp. copy a new song into one of the folders.

I am searching now a way to compare all the songs contained in a *.m3u playlist with all the songs in the
(sub)folders.

The comparison result should tell me e.g.:

\italian\song7.mp3 is currently NOT in ballads.m3u
\italian\song11.mp3 is currently NOT in ballads.m3u
\song325425.mp3 is currently NOT in ballads.m3u
...

How can I achieve this?

Peter

You load one of the playlists into Mp3tag.
Then create a user-defined field e.g. %in_playlist% with the value "yes".
Now you load the rest of the files and filter for
%in_playlist% MISSING
all of the shown files are not in a playlist.
Afterwards you can delete the user-defined field again.

Ok, thank you.

However this task should be doable in an easier way.

Can a new function "Compare Playlist with folder tree" be added in the next release?

Thank you
Peter

Oh, really? I think that this is due to your personal and absolutely individual workflow.
If you modify your workflow and set Mp3tag as the master, then the generation of playlists would be a subordinate step in the workflow an no comparison should be necessary.
What I am thinking about: if you fill the user-defined field for the playlist not just with a "yes" or "no" but with the name or even the names of the playlists to which a track belongs, you can easily filter for tracks that belong to a certain playlist and generate that playlist again. THis then cuts out the comparing task and avoids the problem that renamed files will not appear in MP3tag when you load the playlist.

If you have two text files, the old playlist file and the new playlist file, ...
then you can use applications like WinMerge or Notepad++ or TotalCommander or ...,
to compare the files and see the differences between the two lists.

DD.20150212.1458.CET