Bug 479830

Summary: Vinyl sequence numbers marked as erroneous
Product: [Applications] kid3 Reporter: nelson.suniaga
Component: generalAssignee: Urs Fleisch <ufleisch>
Status: RESOLVED INTENTIONAL    
Severity: minor CC: nelson.suniaga
Priority: NOR    
Version First Reported In: 3.9.x   
Target Milestone: ---   
Platform: Debian stable   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: screenshot of Kid3 displaying files with Track Number frame highlighted in red

Description nelson.suniaga 2024-01-15 04:38:08 UTC 
SUMMARY
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Track Number" frames accepts double side disc sequence numbers (A1, A2, A3, B1, B2, B3), as fetched from Discogs (I haven't test it with another metadata provider), but Kid3 mark them in red with the notice: "Must be numeric or number/total". Once those frames are deleted can't be edited manually, only imported from its filename or from Discogs.

STEPS TO REPRODUCE
1. Click on File > Import data from Discogs.
2. Add the string "vinyl" or "LP" to the Album field.
3. Click Find.
4. Double click on one of the records listed.
5. Click on Close (in the Discogs window).
6. Click on OK (in the Import window).

OBSERVED RESULT

All the files are highlighted in red, as the frame "Track Number".
Hover the mouse pointer over the "Track Number" frame will display the tag: "Must be numeric or number/total".

EXPECTED RESULT

KId3 should accept and manage such type of track sequence numbers. Of course, this feature should come with some modifications in the track number validation and edition to manage the leading letters ("A" and "B", in first instance).

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Debian GNU/Linux 12.4 «Bookworm»
(available in About System)
KDE Plasma Version: 5.27.5-2
KDE Frameworks Version: 5.103.0-1+deb12u1
Qt Version: 5.15.8-2

ADDITIONAL INFORMATION
Comment 1 nelson.suniaga 2024-01-15 14:28:48 UTC 
Created attachment 164915 [details]
screenshot of Kid3 displaying files with Track Number frame highlighted in red
Comment 2 Urs Fleisch 2024-01-15 19:20:22 UTC 
Sorry, this is not a bug, it is simply that ID3v2 does not support non-numeric track numbers. See the ID3v2.4.0 standard https://github.com/id3/ID3v2.4/blob/master/id3v2.4.0-frames.txt:

TRCK
   The 'Track number/Position in set' frame is a numeric string
   containing the order number of the audio-file on its original
   recording. This MAY be extended with a "/" character and a numeric
   string containing the total number of tracks/elements on the original
   recording. E.g. "4/9".

So you will agree that "A1" is not a valid value for a TRCK frame. Someone requested the feature to get these vinyl numbers when importing from Discogs. I can imagine that some players may have problems with such numbers, but most players ignore them anyway. So if you can live with this "standard violation", you can simply ignore it or disable this red highlighting by unchecking "Mark standard violations" in the "Tags/Tag 2" tab of the settings. Otherwise you can only import Discogs entries from CD releases or change the numbers to numeric format after importing, e.g. using Tools/Number Tracks.