Support for disc number in path templates (multi-disc releases)

[jee-r]

Hi @sentriz,

First of all, thanks for wrtag — I’ve been using Beets + Betanin for years, and I’m currently trying to migrate my tagging workflow to wrtag.

With Beets, my paths configuration looked like this:

paths:
  default: $artist_fallback - $album ($fixedyear)/%if{$multidisc,$disc.}$track - $title
  albumtype:single: $artist_fallback - $album ($fixedyear) [Single]/%if{$multidisc,$disc.}$track - $title
  albumtype:ep: $artist_fallback - $album%if{$ep_not_in_title, ($fixedyear) [EP]}/%if{$multidisc,$disc.}$track - $title
  albumtype:live: $artist_fallback - $album ($fixedyear) [Live]/%if{$multidisc,$disc.}$track - $title
  albumtype:bootleg: $artist_fallback - $album ($fixedyear) [Bootleg]/%if{$multidisc,$disc.}$track - $title
  albumtype:soundtrack: $artist_fallback - $album ($fixedyear) [Soundtrack]/%if{$multidisc,$disc.}$track - $title - $artist
  singleton: $artist_fallback - $album ($fixedyear) [Single]/%if{$multidisc,$disc.}$track - $title - $artist
  comp: $albumartist - $album ($fixedyear)/%if{$multidisc,$disc.}$track - $title - $artist

This way, Beets automatically handled multi-disc releases by prefixing track numbers with the disc number only when needed, e.g.:

# disc 1
Pink Floyd - The Wall (1979)/01.01 - In the Flesh.opus
...
# disc 2 
Pink Floyd - The Wall (1979)/02.01 - Hey You.opus

There are some adjustements to do but my current pathFormat in wrtag looks like:

/Media/Music/Opus/{{ artists .Release.Artists | sort | join "; " | safepath }} - {{ .Release.Title | safepath }}{{ if not (eq .ReleaseDisambiguation "") }} ({{ .ReleaseDisambiguation | safepath }}){{ end }} ({{ .Release.ReleaseGroup.FirstReleaseDate.Year }}){{ if ne .Release.ReleaseGroup.PrimaryType "Album" }} [{{ .Release.ReleaseGroup.PrimaryType }}]{{ end }}/{{ pad0 2 .TrackNum }}.{{ len .Tracks | pad0 2 }} {{ if .IsCompilation }}{{ artistsString .Track.Artists | safepath }} - {{ end }}{{ .Track.Title | safepath }}{{ .Ext }}

I saw in the docs that {{ len .Tracks | pad0 2 }} gives the total number of tracks, not the disc number.
Looking at musicbrainz/musicbrainz.go I couldn’t find any field exposing .Track.DiscNumber or something similar.

Would it be possible to expose:

.Track.DiscNumber → the disc number of the track

.Release.Discs (or equivalent) → to check if a release has multiple discs

That way we could write templates like:

{{ if gt (len .Release.Discs) 1 }}
{{ pad0 2 .Track.DiscNumber }}.{{ pad0 2 .Track.TrackNum }}
{{ else }}
{{ pad0 2 .Track.TrackNum }}
{{ end }}

Which would give the exact same flexibility as Beets with %if{$multidisc,$disc.}$track.

Thanks again for your work 🙏

Note:

• {{ len .Tracks | pad0 2 }} return the total tracks => https://github.com/sentriz/wrtag?tab=readme-ov-file#with-disc-and-track-numbers
• release i used for my tests : https://musicbrainz.org/release/118b5e37-d344-40ee-951a-5f8db76d4cfe

[Zariel]

#177

[sentriz]

some breaking changes we're implemented to get this in a good place

• for path-format you must now use .Track.Position instead of .TrackNum, and .Media.TrackCount instead of len .Tracks
• .Media field is now available in templates
• DISCNUMBER tag now correctly reflects disc position for multi-disc releases (was always 1 before)
• DISCSUBTITLE tag written from media title
• path-format validation prevents path formats that would put different discs in different directories

---

@Zariel (and @antifuchs) thank you for the PRs! sorry that I couldn't accept them, for:

• creating multiple folders for a release shouldn't be possible, and the "album root dir" change wasn't needed given that constraint
• a backwards incompatible change, and refactor is better in this case. the manually count track indexes was always going to get us in trouble, so i removed that

so I'm sorry to close those PRs, but @Zariel I added you as a co-author on one of the commits so all credit is not lost

[antifuchs]

Thanks for landing this! I'm happy with any solution, and yours looks very reasonable. I like that .Media is available now, seems very clean.

[gozes]

Two questions from me on this.

1. Is Track.Position relative to the disc or to the release? For example, far a two disc release with 15 tracks on each disc what would be the Track.Position value for the first track on disc 2? Would it be 01 or 16?
   I would think it would be 01 because when you look at the back insert, in the case of a CD, track numbers restart from 01 on each disc in the release.

2. I really want to try out this feature but I don't see it listed on the release that went out a few days ago so can we have a .1 so that the docker container gets build again with this feature in it?

[sentriz]

for a two disc release with 15 tracks on each disc, what would be the Track.Position value for the first track on disc 2? Would it be 1 or 16?

that would be 1, yes 👍

I really want to try out this feature but I don't see it listed on the release that went out a few days ago

this stuff will be coming on the next release 0.30.0, when that PR is merged, the release is created. if you'd like to try it now, I would recommend cloning the repo, and in your docker-compose change "image: x" to be "build: path/to/repo"

[jee-r]

Wow thank you everyone !!

I have a question about conditional prefix i mean add Media.Position only on multi discs release

I see there is a DISCTOTAL ref in

wrtag/tags/normtag/normtag.go

Line 46 in 3d7fa95

DiscTotal = "DISCTOTAL" //tag: alts "TOTALDISCS" "TOTALDISKS" "TOTALDISC" "TOTALDISK"

but i'm not sure if this is usable in template as a condition

I would do something like this

{{ if gt (len <DISCTOTAL GOES HERE>) 1 }}
{{ pad0 2 .Media.Position }}.{{ pad0 2 .Track.Positon }}
{{ else }}
{{ pad0 2 .Track.Position }}
{{ end }}

Is there a way to do that ?

[sentriz]

Wow thank you everyone !!

I have a question about conditional prefix i mean add Media.Position only on multi discs release

I see there is a DISCTOTAL ref in

wrtag/tags/normtag/normtag.go

Line 46 in 3d7fa95
DiscTotal = "DISCTOTAL" //tag: alts "TOTALDISCS" "TOTALDISKS" "TOTALDISC" "TOTALDISK"
but i'm not sure if this is usable in template as a condition

I would do something like this

{{ if gt (len <DISCTOTAL GOES HERE>) 1 }}
{{ pad0 2 .Media.Position }}.{{ pad0 2 .Track.Positon }}
{{ else }}
{{ pad0 2 .Track.Position }}
{{ end }}

Is there a way to do that ?

hey, yes, there is a reference to the medias in .Release, so you can do

{{ if gt (len .Release.Media) 1 }}{{ pad0 2 .Media.Position }}.{{ end }}{{ pad0 2 .Track.Position }}

[jee-r]

Thank's a lot @sentriz , Party on 🥳

Edit:
For those who want to test it with Docker or Podman: ( amd64 only )
https://github.com/users/jee-r/packages/container/wrtag/650176628?tag=0.30.0