Feature Request: Support for more MP4 metadata boxes

Hi all,

I have compatibility issues on metadata of MP4 files, and an enhancement of MP3Tag could help.

Reading the Atomic Parsley documentation, I found out that the MP4 metadata format consists of boxes (also called atoms) that have one out of two formats. I call the first format native and the second format dash. A box in native format simply holds a name and a value. A box in dash format has the name "----" (four dashes) and contains a mean property of fixed value com.apple.iTunes followed by a name and a value (looks like the same idea as the TXXX field in the ID3v2 standard).

As I wrote in another thread, I use a media center software that relies on TagLib# for tagging. Amongst others, it expects the following boxes in native format:

  • Conductor: cond
  • Standard Genres: gnre
  • Custom Genres: @gen
MP3Tag writes these fields in dash format, so they are not available in my media center software. There's curently no way to create a custom mapping for this purpose. Thus I 'd like to see an option to write these fields as native boxes.

For the sake of completeness, I created a list of all native boxes from the TagLib# source code:

  • IsCompilation: cpil
  • Title: @nam
  • Artist: @ART
  • Album Artist: aART
  • Composer: @wrt
  • Album: @alb
  • Comment: @cmt
  • Conductor: cond
  • Standard Genres: gnre
  • Custom Genres: @gen
  • Year: @day
  • Track number & total of tracks: trkn
  • Disc number & total of discs: disk
  • Lyrics: @lyr
  • Album grouping: @grp
  • BPM: tmpo
  • Copyright: cprt
  • Sort Order Album Artist: soaa
  • Sort Order Artist: soar
  • Sort Order Album: soal
  • Sort Order Title: sonm