So should I introduce those as two new lines of code or am I supposed to replace existing?
Either $if($eql(%artist%,%albumartist%),1,0) could be implemented before Guess values, before Format value Filename/Title or replaces one or more of these?
Or was that just an example and the true coding is the second line you mentioned Format string: $if($eql(%artist%,%albumartist%),%feat_artist%,%artist%)?
The sequence I see is:
First guess value so that the FEAT_ARTIST has a chance to get filled with the after-comma-data.
Now compare ARTIST and ALBUMARTIST - if they to not match, write ARTIST to FEAT_ARTIST otherwise leave FEAT_ARTIST as it is.
Now I would update the TITLE with [feat ...]
and finally rename the file with
%track% %title%
(as TITLE should contain the feat... part by now. In that order you do not have to add the feat... part twice: once to TITLE and once to _FILENAME)
I don't think so.
Actions 1&2&3: ok
Action 4 should have FEAT_ARTIST as field to be formatted and not _FILENAME
Action 5 & 6 are a complete chaos of target fields and format strings.
Action 5 should format TITLE with format string: %title%[ (feat. %feat_artist%)]
Action 6 should format _FILENAME with format string: %track% _ %title%
However, it adds the track number to the filename again so for example '15 Lost Stars' turns into '15 15 Lost Stars (feat. Adam Levine)' and the artist name remains Adam Levine rather than being replaced by Album Artist.
If you replace text constants like "(Album)" then it is not necessary to use a regular expression (that is specifically good if you deal with patterns of variable contents) but just a plan "Replace".
I would use an action of the type "Format value" for _DIRECTORY to get a unified naming scheme. So instead of cutting away pieces of the string, rewrite it completely with e.g.
Format string: %year% - %album%
I have a specific and peculiar problem with Artist vs Album Artist. I used to have my cell phone music (~2000 tracks) all done up nicely with both fields correct. If the track is "Moves Like Jagger," then Artist was "Maroon 5 & Christina Aguilera" and Album Artist was "Maroon 5." HOWEVER, I bought a new car with Bluetooth and I can play music with my phone in my pocket and it's displayed on a dash panel. BUT ... the display shows Title and Artist only and it was Album Artist it was displaying. I experimented & found if there was no Album Artist tag, it would display just Artist. SO, I did an Mp3tag export and looked for all case where Artist & Album Artist were not equal and blanked out the Album Artist tag in those cases. Now my car display really shows me who the artist is! (It bothers my perfection gene, but if I ever wanted to fix the tags as they should be, it would be pretty easy.)