Tags: multiple genres

[Huebi]

Hi,

adding more than one genre to the id3v2 tags in mp3 files works fine so far. All genres are taken into account and the files are still playable. In the audio info the genres are listed as comma separated lists. So i justed tested to add multiple genres in that way into tha mpo3 file, but this isnt than split up but appears as "genre 1, genre2" in moOde.

I will open an issue for MPD on github, but i guess this will take a while until this implemented in MPD und find its way to moOde, if at all.

But i would apreciate if i can select more than one genre in the library tag view and only those files are listed having all of the selected genres

[TheOldPresbyope]

Before you post an MPD issue I suggest you check to see what previously has been opened (and mostly closed) on the subject. As well, you'll get a sense of the kind of reception (hint - brusque) you'll get. 

From past experience [1] and a quick re-browse of the issues, I suspect the short answer will be some combination of 

1. MPD already returns multiple values for a tag type if the file type and metadata specification support it, and
   
2. "show me where the ID3v2.3/4 specifcations support multiple genre values".
   

I could be wrong of course, so feel free to chime in.

Regards,
Kent

[1] So far, I think my record of getting an MPD issue accepted is 1 win, 1 loss, and 1 no-decision. At least that's how I remember them. The win was to get "work" accepted as a recognized tag type.

[Huebi]

D3v2.4 was published on November 1, 2000. It allows text frames to contain multiple values, separated with a null byte. Textual data to be encoded in UTF-8 rather than UTF-16. Another new feature allows the addition of a tag to the end of the file before other tags (like ID3v1)

Maybe MPD is already supporting that. But i wasnt able to find a Tageditor for 2.4, only 2.3. I will do a little bit more investigation before opening an issue.

[TheOldPresbyope]

Mp3tag claims ID3v2.4 support if you like GUI-based editors. If you're into programming in Python you might find mutagen to be useful, although it takes some experimenting with when you're new to it. (It's the nearest thing to a "Swiss army knife" I know for audio  metadata.)

By all means first test MPD with a properly constructed and validated metadata test file and have it available (cuz you'll be asked for it) before posting any issue about MPD not doing something right with music metadata. I always construct them from test tones so I know they contain no copyrighted material.

I personally consider the ID3 metadata scheme(s) to be a hot mess and prefer to have nothing with it so I'll bow out here.

Good luck.

Regards,
Kent

PS - be sure to familiarize yourself with the ID3 text frame concept and the various defined text frame types. Read both v2.3.0 and v2.4.0 specs, specifically about text frame type "TCON" (for "content type") which is where genre values get stashed. See how peculiar life can get.

[Huebi]

Hi,

finally there is no need to open an issue for MPD

This is what i have done:

Updated my (very) old version of kid3 which is able to handle ID3v2 2.4 format. The specs of the format says that multiple values are possible separated by a null byte. In kid3 you need to separate multiple values by the pipe character | which is replaced by the null byte when saving.

In kid3 you need to convert the ID3v2 2.3 to 2.4 via Tools|Convert

Now you can enter multiple values separated by |. This does not work with version 2.3, the content will not be split at the separator.

This is not only possible for genre but for other tags as well (see kid3 user manual). Its also helpful, for example, if you have a duet and want both singers to be handled separately as well. "A&B|A|B" would then link the same file to A&B, A and B.

MPD is handling those entries fine and moOde displays them properly.

I did my research with kid3 and i don't know how to do this in other tag editors, this may differ.

Before doing this make sure your favorite player supports 2.4.

Thanks for all contributing on this topic pushing me in the right direction.

[TheOldPresbyope]

Nice!

[Nutul]

Yeah, indeed nice, just tested it out.

Only thing: I use mediainfo to extract metadata from the files and build an html of my library, and when it comes to these id3v2.4 tags, it reports the first genre only.
I think this is due to the \0 as separator: it does not break older software (\0 is a string terminator in C); but it not being aware of the v2.4 (which, I believe, uses a double \0\0 to terminate the tags, and a single \0 to separate list elements) just assumes the tag end on the first \0 encountered.
So, maybe wait for an updated version of mediainfo...

TTYTT this is not an issue for me at all, as I only use FLAC with Vorbis comment, but it's worth mentioning, in case someone else is using mediainfo too.

Most probably, to be covered up, I better use the library JSON generated by MPD, and use that to build my html; it will save me some time too, as extracting the metadata from my - almost - 1000 single-album FLACs takes a good few minutes.

[TheOldPresbyope]

Strikes me that the mediainfo devs didn't read the spec carefully when they added ID3v2.4 to their repertoire (the curse of the seemingly incremental upgrade which isn't so incremental) but I don't see an easy way to post an issue to their site. They clam to be an opensource effort but obscure how/where it's done.

Since you already have your test file, I'm curious if exiftool handles multi-valued Id3v2.4 text frames correctly.

And I totally get why you want to start using MPD's database file directly. Besides the time factor, it means both moode and your Library UI are navigating from the same map, so to speak.

Regards,
Kent

[Nutul]

(...)

Since you already have your test file, I'm curious if exiftool handles multi-valued Id3v2.4 text frames correctly.

And I totally get why you want to start using MPD's database file directly. Besides the time factor, it means both moode and your Library UI are navigating from the same map, so to speak.

Hi Kent,

I'll give exiftool a try, as soon as I find half an hour to install and play around with it.

And yes, you absolutely got the point about navigating from the same map :-)

[Huebi]

but I don't see an easy way to post an issue to their site.

https://github.com/MediaArea/MediaInfo