Applescript: Help to extract PDF "Author" metadata and set it in iTunes Author field
This uses the built in unix commands to get the Author.

Try it and let me know if it needs a tweak.

tell application "iTunes"

    set sel to the selection

    if sel is {} then display dialog "Please select something" buttons {"Cancel"}

    repeat with i from 1 to count of sel

        set the_track to item i of sel

        set the_posix_path to POSIX path of (location of the_track as alias)

        set authorfield to paragraph 2 of (do shell script "mdls -name kMDItemAuthors " &amp; quoted form of the_posix_path &amp; "|  awk -F\\\" '{print $2'}")

        set artist of the_track to (authorfield &amp; "-") as string
    end repeat


end tell