Mixxx reads ID-tags from some flac-files only

I have many FLAC-files in my music library, and some of the files are listed with tags, some only with filename.
I loaded one of the files into audacity and the tags are shown there.
When i export the file (as FLAC) to a new filename, the tags are preserved, and mixxx then shows the tags from the new file.
also, this problem seems to only affect FLAC files.

why does the tag reader from mixxx only accept some tags, and how can i resolve that?

thanks in advance!

Maybe you added the tags after adding the file to the Mixxx library? Try right clicking on the track and Reimport the Metadata from file tags.

I re-imported the tags from the file, but no success.

When i export to WAV from audacity, the tags are also preserved and mixxx does find them.

Sidenote: loading the file in easytag also shows the tags.

What? AFAIK the WAV format doesn’t support tags at all.

The interesting point is that this problem does not affect every FLAC file.

Shall i offer an example file pair (original and re-exported version)?

WAV is a tagged file format which does in fact support tags, and mixxx shows the tags correctly.

ok, here for your local test within mixxx:
http://mondkalbantrieb.de/FLACtest-original.flac
http://mondkalbantrieb.de/FLACtest-reexported.flac

The first file is the one which mixxx shows no tags.
The second file was loaded in audacity and reexported as flac, where mixxx shows the tags as expected.

IMHO, the problem is in the tag reader for FLAC. It seems like the tag reader does not like some variants of the FLAC format.

TagLib does not detect the VorbisComment tags in this file:

Warning [LibraryScanner 1]: TagLib - Cannot read audio properties from inaccessible/unreadable/invalid file: /home/uk/Music/Corrupt Tracks/2020-10-16 flac no tags/FLACtest-original.flac

But the tags exist:

$ metaflac --list /tmp/FLACtest-original.flac 
METADATA block #0
  type: 0 (STREAMINFO)
  is last: false
  length: 34
  minimum blocksize: 4608 samples
  maximum blocksize: 4608 samples
  minimum framesize: 14 bytes
  maximum framesize: 14215 bytes
  sample_rate: 44100 Hz
  channels: 2
  bits-per-sample: 16
  total samples: 10773924
  MD5 signature: 1ab68785ca0de1294fa8b85847ef6536
METADATA block #1
  type: 3 (SEEKTABLE)
  is last: false
  length: 0
  seek points: 0
METADATA block #2
  type: 4 (VORBIS_COMMENT)
  is last: false
  length: 204
  vendor string: reference libFLAC 1.3.2 20170101
  comments: 8
    comment[0]: TITLE=Suburbia
    comment[1]: ARTIST=Pet Shop Boys
    comment[2]: ALBUM=Please
    comment[3]: DATE=1986
    comment[4]: TRACKNUMBER=02
    comment[5]: TRACKTOTAL=06
    comment[6]: GENRE=Synthie-Pop, Dance
    comment[7]: DESCRIPTION=Single-Version
METADATA block #3
  type: 1 (PADDING)
  is last: true
  length: 130
$ metaflac --list /tmp/FLACtest-reexported.flac 
METADATA block #0
  type: 0 (STREAMINFO)
  is last: false
  length: 34
  minimum blocksize: 4096 samples
  maximum blocksize: 4096 samples
  minimum framesize: 944 bytes
  maximum framesize: 12804 bytes
  sample_rate: 44100 Hz
  channels: 2
  bits-per-sample: 16
  total samples: 10773924
  MD5 signature: 4ffb1a64715d7ce0897ab2827588a043
METADATA block #1
  type: 4 (VORBIS_COMMENT)
  is last: true
  length: 157
  vendor string: reference libFLAC 1.3.3 20190804
  comments: 6
    comment[0]: TRACKNUMBER=02
    comment[1]: GENRE=Synthie-Pop, Dance
    comment[2]: DATE=1986
    comment[3]: ARTIST=Pet Shop Boys
    comment[4]: ALBUM=Please
    comment[5]: TITLE=Suburbia

The original file contains an empty SEEKTABLE and final PADDING metadata block. Unfortunately, we are not able to fix this in Mixxx.

Try to switch from libFLAC 1.3.2 to 1.3.3 for new files or repackage your existing files.