Trial and error genre not genres dependant

[JOJ0]

Just some trial and error approach for now. Details later.

Todo: Investigate what the default name for genre tag is according to whoever invented it and if it is common to use a "genres" plural tag as well (I guess not and wonder how difficult it is to find out what is contained in a genre tag - a list or a string, ....) Investigate, investigate more....

Read this for newer tags: https://id3.org/id3v2.4.0-frames

Read maybe this for older tags:

• https://id3.org/d3v2.3.0
• https://web.archive.org/web/20161124001116/
• http://id3.org/id3v2-00
• https://id3.org/ID3v1

Links source: https://en.wikipedia.org/wiki/ID3#References

[JOJ0]

Todo: Investigate what the default name for genre tag is according to whoever invented it and if it is common to use a "genres" plural tag as well (I guess not and wonder how difficult it is to find out what is contained in a genre tag - a list or a string, ....) Investigate, investigate more....

The genre tag's official name is difficult to find....no luck so far. I think there is no real definition. Naming it "GENRE" is just what people use. Update 30 minutes later: looking for genre is misleading since the tags actual name is TCON

ID3v2.4 introduces a definition for lists to be saved as strings with NULL characters separated.

In case of ID3v2.3 obviously there is no definition for lists. It can only be a string. Any list handling must be done on another (higher) level.

So to answer my own questions:

• It looks like that most of the time programs call it GENRE singular and GENRES would be something nobody uses. If this is a list or not can not really be determined.
• In reality the tag "frame" that is written to is TCON (Content Type).
  • puddletag has a nice list: https://docs.puddletag.net/source/id3.html
  • and mediafile's genres property saves to that frame as well.

    mediafile/mediafile.py

    Lines 1771 to 1775 in e1de364

    	genres = ListMediaField(
    	MP3ListStorageStyle('TCON'),
    	MP4ListStorageStyle('\xa9gen'),
    	ListStorageStyle('GENRE'),
    	ASFStorageStyle('WM/Genre'),

  • and this is how mutagen docs describe it https://mutagen-specs.readthedocs.io/en/latest/id3/id3v2.4.0-frames.html#tcon

More questions

• Not sure how mediafile saves a list to the file (beets supports id3v2.3 and 2.4 as well, IIRC) and whether it uses the NULL character or a self-defined delimieter (to stay 2.3 compatible)-> read the fine code....
• Still it's confusing to me that we write to a property that is named plural genres, and then there is a singular genre property, that has not really a purpose (from reading code it should be able read and write the very first entry of genre - in the case of genre, this does not really make sense:

  mediafile/mediafile.py

  Lines 1303 to 1306 in e1de364

  	def single_field(self):
  	"""Returns a ``MediaField`` descriptor that gets and sets the
  	first item.
  	"""

• Has the NULL character we use in beets as the list delimiter anything to do with the id3v2.4 delimiter? Or do we abstract that anyway and it was "just chosen" in beets for whatever reason.

Maybe genre and genres mediafile properties should indeed be synonyms, or even better, one of them removed.

[JOJ0]

this is actually wrong. should be TCON, if genre should be a "simple string version" of genres plural.

[JOJ0]

This was just an experiment. Some useful research on id3 tags in there though. Closing.