Support disc titles / ID3 frame "Set subtitle" (TSST)

[sk222 5]

The ID3 specification includes a frame called TSST (Set subtitle), defined as

  TSST
   The 'Set subtitle' frame is intended for the subtitle of the part of
   a set this track belongs to.

right below the frame used for disc number, TPOS (Part of a set):

  TPOS
   The 'Part of a set' frame is a numeric string that describes which
   part of a set the audio came from. This frame is used if the source
   described in the "TALB" frame is divided into several mediums, e.g. a
   double CD. The value MAY be extended with a "/" character and a
   numeric string containing the total number of parts in the set. E.g.
   "1/2".

Other tag formats seem so have this kind of field to, quoting https://www.blisshq.com/music-library-management-blog/2018/03/27/lamentable-state-disc-title-support/

Quote

ID3 (used in MP3) only introduced formal support in ID3v2.4 using the TSST frame. It is possible to use the same frame in earlier versions of ID3v2 but it's less likely to be supported.

For FLAC and Vorbis which, commonly, use the same tagging approach of Vorbis Comments, DISCSUBTITLE is normally used. In some cases, for some music players, you may need to use SETSUBTITLE instead.

For MP4 and WMA, this is where the fun starts. A number of tag editors have documented their mappings. For example, MP4's is documented as ----:com.apple.iTunes:DISCSUBTITLE and WMA's WM/SetSubTitle; in other words, that's where the subtitle will be stored in a MP4/WMA file if you happen to use that tag editor to save one.

I'd propose displaying the disc (sub)titles (in this example: "SURGE", "RAPTURE" and "SHIMMER") something like this:

My example is definitely not the most "real-world" one (I added the tags myself as the original album, as downloaded from Bandcamp, consists of multiple albums, each representing a disc), but there's definitely more use cases, as seen in this screenshot of the implementation in Navidrome:
https://github.com/navidrome/navidrome/issues/272#issuecomment-627497195

Edited February 23, 2025 by sk222

[Luke 42077]

Hi, yes this question has come up before and is possible for future updates. Thanks for the feedback.

[user24 313]

Having a Disc Subtitle field next to the existing Disc Number field is a great suggestion and being able to import the info from the relevant embedded metadata tag(s) would be even better!

I’ve read many of the older forum posts about this, which I mostly agree with, but I think there is one aspect that hasn’t been fully discussed…

While some of my multi-disc albums have a separate subtitle for the individual discs, I also have many album re-releases (single-disc, multi-disc, bonus tracks, deluxe edition, anniversary edition, box set) where there is more than one subtitle per disc. An example is Pet Sounds [50^th Anniversary Edition] where some numbered discs have several subtitles:

With this example (plus many others I have looked at), MusicBrainz (LHS image below) groups the tracks by Disc Number, however Discogs (RHS image below) groups the tracks by Disc Subtitle:

https://musicbrainz.org/release/b5474125-17b3-4893-ba39-267b28ba9fb3

https://www.discogs.com/release/8738209-The-Beach-Boys-Pet-Sounds

I sightly prefer the Discogs method, but each has pros and cons. Therefore, perhaps Emby could consider both methods for any possible future implementation? (Or maybe grouping by Both rather than just Disc Number.)

Some sort of Group By: None | Disc Number | Disc Subtitle | Both would allow for ultimate flexibility, but I would be quite happy with even just a basic Disc Subtitle field, as suggested by others already. If this field/tag was available, it would be very useful for at least showing the titles and (if wanted) alternative track groupings could then potentially be further customized with creative tagging and basic CSS…

Having different track grouping options may also be useful for Classical Music and Audiobooks?

Thanks for considering!