VLC Lua script to extract artist and title metadata from the filename

artist_title.lua

--[[
Tries to extract artist and title from the filename.
Expected file name format: <artist> - <title>.ext

Usage: put this script inside <vlc-dir>/lua/meta/fetcher folder (create if not present).
If a music file is opened without meta tags, the script analyzes the filename and, if the pattern applies, sets the extracted artist and title info as metadata.
--]]

function descriptor()
    return { scope="local" }
end

function fetch_meta()
    local metas = vlc.item:metas()

    -- Don't do anything if there is already a title or artist
    if metas["title"] or metas["artist"] then
        return
    end

    local name = metas["filename"];
    if not name then
        return
    end

    -- Find "artist - title.ext"
    _, _, artist, title = string.find(name, "^(.+) %- (.+)%..+$")
    if not artist or not title then
        return
    end

    vlc.item:set_meta("title", title)
    vlc.item:set_meta("artist", artist)
end