Prefer nfo (or musicbrainz metadata) to music tags

[df1ad]

Is it possible for Jellyfin to use metadata in an album.nfo (or MusicBrainz) instead of the metadata tagged in the files?

I did the following test:
1. Add album to Jellyfin library
2. Turn on nfo saver for Music library
3. Add album MBID to album in Jellyfin web
4. Refresh metadata > Replace all metadata (including images)
(album.nfo gets saved, track titles and album title still use metadata from file tags)
5. Make some manual changes to metadata via Jellyfin web, e.g. change album title and some track titles
(see changes are reflected in album.nfo)
6. Remove album from music folder, wait for library refresh
7. Turn off nfo saver for Music library
8. Re-add album to music folder, wait for library refresh

The result in the library is an album that has the album and release-group MBIDs (which must have come from the album.nfo, because they weren't present on initial import, ie step 1 above) but still uses track titles and album title from the tags. Track titles and album title from album.nfo are ignored.

I also noticed that if I do:
9. Re-introduce manual changes to metadata via Jellyfin web
10. Refresh metadata > Search for missing metadata

Then my metadata changes are undone, and tag metadata for album title and track titles is used again. Why should that be if I only "searched for missing metadata?"

The album.nfo is below if that helps. No manual editing of this file, just the process described above (after step 5).

Code:

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<album>
  <review />
  <outline />
  <lockdata>false</lockdata>
  <dateadded>2023-12-16 20:47:15</dateadded>
  <title>Flash Gordon</title>
  <year>1980</year>
  <premiered>1980-01-01</premiered>
  <releasedate>1980-01-01</releasedate>
  <runtime>48</runtime>
  <genre>Rock</genre>
  <musicbrainzalbumid>c8a6c0d4-1fe4-4940-a0df-cfb112f9800c</musicbrainzalbumid>
  <musicbrainzreleasegroupid>70bd9521-c3ea-38c9-9d67-a6a6100bfa48</musicbrainzreleasegroupid>
  <art>
    <poster>/media/buggy/var/lib/jellyfin/metadata/library/35/35e72663627f0f51cf2b2d1ab090f4ad/folder.jpg</poster>
  </art>
  <artist>Queen</artist>
  <albumartist>Queen</albumartist>
  <track>
    <position>1</position>
    <title>Flash's Theme</title>
    <duration>03:29</duration>
  </track>
  <track>
    <position>2</position>
    <title>In The Space Capsule (The Love Theme)</title>
    <duration>02:42</duration>
  </track>
  <track>
    <position>3</position>
    <title>Ming's Theme (In the Court of Ming the Merciless)</title>
    <duration>02:40</duration>
  </track>
  <track>
    <position>4</position>
    <title>The Ring (Hypnotic Seduction Of Dale)</title>
    <duration>00:57</duration>
  </track>
  <track>
    <position>5</position>
    <title>Football Fight</title>
    <duration>01:28</duration>
  </track>
  <track>
    <position>6</position>
    <title>In The Death Cell (Love Theme Reprise)</title>
    <duration>02:24</duration>
  </track>
  <track>
    <position>7</position>
    <title>Execution Of Flash</title>
    <duration>01:05</duration>
  </track>
  <track>
    <position>8</position>
    <title>The Kiss (Aura Resurrects Flash)</title>
    <duration>01:44</duration>
  </track>
  <track>
    <position>9</position>
    <title>Arboria (Planet Of The Tree Men)</title>
    <duration>01:41</duration>
  </track>
  <track>
    <position>10</position>
    <title>Escape From The Swamp</title>
    <duration>01:43</duration>
  </track>
  <track>
    <position>11</position>
    <title>Flash To The Rescue</title>
    <duration>02:43</duration>
  </track>
  <track>
    <position>12</position>
    <title>Vultan's Theme (Attack Of The Hawk Men)</title>
    <duration>01:12</duration>
  </track>
  <track>
    <position>13</position>
    <title>Battle Theme</title>
    <duration>02:18</duration>
  </track>
  <track>
    <position>14</position>
    <title>The Wedding March</title>
    <duration>00:56</duration>
  </track>
  <track>
    <position>15</position>
    <title>Marriage Of Dale And Ming (And Flash Approaching)</title>
    <duration>02:04</duration>
  </track>
  <track>
    <position>16</position>
    <title>Crash Dive On Mingo City</title>
    <duration>01:00</duration>
  </track>
  <track>
    <position>17</position>
    <title>Flash's Theme Reprise (Victory Celebrations)</title>
    <duration>01:23</duration>
  </track>
  <track>
    <position>18</position>
    <title>The Hero</title>
    <duration>03:33</duration>
  </track>
  <track>
    <position>1</position>
    <title>Flash (Single Version)</title>
    <duration>02:49</duration>
  </track>
  <track>
    <position>2</position>
    <title>The Hero (October 1980... Revisited)</title>
    <duration>02:57</duration>
  </track>
  <track>
    <position>3</position>
    <title>The Kiss (Early Version, March 1980)</title>
    <duration>01:12</duration>
  </track>
  <track>
    <position>4</position>
    <title>Football Fight (Early Version, No Synths! - February 1980)</title>
    <duration>01:56</duration>
  </track>
  <track>
    <position>5</position>
    <title>Flash (Live in Montreal, November 1981)</title>
    <duration>02:12</duration>
  </track>
  <track>
    <position>6</position>
    <title>The Hero (Live in Montreal, November 1981)</title>
    <duration>01:48</duration>
  </track>
</album>

[tmsrxzar]

see https://jellyfin.org/docs/general/server/metadata/nfo/
note that albumartist and tracktitle are not among the supported tags according to the official documentation

most of that should be encoded into the files themselves via id3, maybe musicbrainz picard(?)

[df1ad]

Any idea of the rationale for supporting writing of fields that cannot be read back again? And just to steer back to my original question, are id3 tags the only supported method for getting this metadata? I have some constraints preventing me from writing to the files themselves.