Multiple artists appear as one when using FLAC files with multiple ARTISTS tags

[MarinBernard]

Hi,

Quick description

When Emby scans FLAC files for metadata and finds several ARTISTS tags in a single file, it concatenates the values of the ARTISTS tags into the Artist field of the track metadata with a semicolon delimiter. However, Emby treats the final string as a single artist, ignoring the semicolon delimiter. The same string would generate several artist records if edited manually.

Long description

I use the latest version of Emby Server on CentOS 7.1503. I have a FLAC-only audio library configured in Emby Server. The files are tagged using MusicBrainz Picard. Recently, the developers have added support for the ARTISTS tags (note the plural) in FLAC files. As a consequence, when a FLAC file contains several of those tags, the scanner concatenates all the values in the Artist field of the track metadata. The semicolon acts as a delimiter.

For instance, one of my files have the following metadata:

$ metaflac --export-tags-to=- File.flac 
BARCODE=0035627460227
PRODUCER=Dave Stewart
TITLE=There Must Be an Angel (Playing With My Heart) (feat. Stevie Wonder)
RELEASECOUNTRY=XE
TOTALDISCS=1
LABEL=BMG
LABEL=RCA
TOTALTRACKS=9
MUSICBRAINZ_ALBUMARTISTID=b4d32cff-f19e-455f-86c4-f347d824ca61
DATE=1990
DISCNUMBER=1
TRACKTOTAL=9
ENGINEER=Jay Willis
ENGINEER=Adam Williams
ENGINEER=Don Smith
ALBUMARTISTSORT=Eurythmics
ORIGINALDATE=1985
LANGUAGE=eng
SCRIPT=Latn
WORK=There Must Be an Angel (Playing With My Heart)
MUSICBRAINZ_ALBUMID=b79941ef-9d54-4aca-8c79-4eeb164f05d3
RELEASESTATUS=official
ALBUMARTIST=Eurythmics
CATALOGNUMBER=ND 74602
MUSICBRAINZ_RELEASETRACKID=e0821bfb-e6b9-3825-9db6-ac7916eafdad
ALBUM=Be Yourself Tonight
MUSICBRAINZ_ARTISTID=b4d32cff-f19e-455f-86c4-f347d824ca61
MUSICBRAINZ_ARTISTID=1ee18fb3-18a6-4c7f-8ba0-bc41cdd0462e
MEDIA=CD
RELEASETYPE=album
MIXER=Dave Stewart
MIXER=Adam Williams
ORIGINALYEAR=1985
PERFORMER=Dean Garcia (bass guitar)
PERFORMER=Michael Kamen (strings)
PERFORMER=Olle Romo (drums)
PERFORMER=Angel Cross (background vocals)
PERFORMER=Dave Stewart (keyboard)
PERFORMER=Annie Lennox (keyboard)
PERFORMER=Annie Lennox (lead vocals)
PERFORMER=Stevie Wonder (guest harmonica)
ARTIST=Eurythmics
MUSICBRAINZ_RELEASEGROUPID=c40266f2-4f32-3dde-a639-6672ed7a4e6c
DISCTOTAL=1
WRITER=Dave Stewart
WRITER=Annie Lennox
MUSICBRAINZ_WORKID=792f5861-8d6d-3c8a-93a9-e17b06150295
MUSICBRAINZ_TRACKID=d2328fb6-b5e0-40e3-bd4b-605a481fb451
ARTISTSORT=Eurythmics feat. Wonder, Stevie
ARTISTS=Eurythmics
ARTISTS=Stevie Wonder
TRACKNUMBER=2

This file has two ARTISTS tags:

$ metaflac --export-tags-to=- File.flac | grep ARTISTS=
ARTISTS=Eurythmics
ARTISTS=Stevie Wonder

In Emby Server, those tags are converted into a single Artist value with both artists and a semicolon delimiter. Everything is fine so far:

However, if I make a search, the whole string is considered as a single artist instead of two (the single "Eurythmics" artist comes from another track):

If I click the item, I can see the actual song:

However, if I manually edit the track's metadata with the same values (removing the semicolon in the Artist field, saving, restoring the semicolon, saving again), Emby behaves as expected and generates two distinct artists. The track now appears under the main Eurythmics artist (note that Emby now automatically replaces the semicolon by a comma to show that the track has several artists):

[MarinBernard]

Fixed in 3.0.5785.