Unknown artist
 

Some songs are shown as unknown artist in the lists of Artists, Playlists, etc. However, when I click on an unknown artist song and start playing it, winamp shows the name of the artist.

In the list views, winamp does not show the length of the unknown artist songs, but times are shown when playing the songs.

I tried clearing the media storage data and rebooting, but that didn't help.

The songs are properly tagged according to mp3tag, foobar2000 and itunes. I don't have desktop winamp, so I haven't checked that.

I've seen other posts regarding unknown artist problems, but none with this specific oddity.

Why would winamp show the artist name of a song when playing the song, but show it as unknown artist in the various list views? Any fixes?

The problem can be fixed by running

ffmpeg -i file.m4a -vn -codec copy newfile.m4a
or
ffmpeg -i file.m4a -codec copy newfile.mp4

BTW, ffmpeg -i file.m4a -codec copy newfile.m4a shows an error on all of my m4a files, whether or not they are a problem for winamp.