MP4 CONDUCTOR tag not recognized by LMS

[schup011]

Hi,

I got a new bunch of classical CDs ripped with iTunes from someone else. Most of them are in the MP4 format (extension .m4a).

I usually use FLAC encoding, and I use the CONDUCTOR, BAND and COMPOSER tags which are then also displayed on the piCorePlayer via a "Custom Clock" Screen.

Now with the MP4 tracks, I also retagged everything and filled the CONDUCTOR, BAND and COMPOSER tags. But LMS does not seem to recognize the CONDUCTOR tag.

Some of the albums I have both ripped in FLAC and MP4, and tagged with mp3tag.

This is what LMS shows (Web Interface: Display Tags):

FLAC Version:
This is shown if you click on the track, next to the albumart:

Album-Interpret: Berliner Philharmoniker
Band/Orchester: Berliner Philharmoniker
Komponist: Anton Bruckner
Dirigent: Günter Wand
Album: Anton Bruckner - Symphonie Nr. 9

This is shown if you then click on "View tags":

ALBUM: Anton Bruckner - Symphonie Nr. 9
ALBUMARTIST: Berliner Philharmoniker
BAND: Berliner Philharmoniker
COMPOSER: Anton Bruckner
CONDUCTOR: Günter Wand

MP4 Version:
This is shown if you click on the track, next to the albumart:

Album-Interpret: Berliner Philharmoniker
Band/Orchester: Berliner Philharmoniker
Komponist: Anton Bruckner
Album: B E2 - Bruckner: Symphony #9

This is shown if you then click on "View tags":

AART: Berliner Philharmoniker
ALB: B E2 - Bruckner: Symphony #9
BAND: Berliner Philharmoniker
CON: Günter Wand 
WRT: Anton Bruckner

I have omitted many other tags, because they don't matter.

So the CONDUCTOR tag, although correctly tagged and visible in mp3tag and TagScanner, is not recognized.

Does anyone understand what is going on?

Thanks!

[schup011]

@mherger:

I found the tagMapping section on GitHub where the "CON" tag is not mapped to "CONDUCTOR":

https://github.com/Logitech/slimserv...rmats/Movie.pm

Could this be the reason? If so, I think it is just one line of code that is missing. It would be new line 23:


CON => 'CONDUCTOR',

Would you be so kind to add it, or could I do it (currently not active on GitHub yet)?

[mrw]

LMS will recognize a conductor tag if it is present in the form of an iTunes "reverse DNS format tag". Specifically
----:com.apple.iTunes:CONDUCTOR.

It is referenced here: https://picard.musicbrainz.org/docs/mappings/

I don't have any useful experience with tag editors, perhaps yours has an option to use this form ?

I can add this conductor tag using AtomicParsley, as follows:

AtomicParsley 'MyTrack.m4a' --rDNSatom "The conductor name" name=CONDUCTOR  domain=com.apple.iTunes

AtomicParsley refers to this type of metadata as "the reverse DNS format", I don't know what others call it.

Perhaps you can find a way of manipulating your new collection accordingly.

[mherger]

What OS are you running your LMS on? You could give this a try yourself if it was anything other than Windows...

[schup011]

I am using piCorePlayer with integrated LMS on a RPi 3 B+.

I am not familiar with the LMS code. Can I find the source file on the RPi and change it myself??

[schup011]

LMS will recognize a conductor tag if it is present in the form of an iTunes "reverse DNS format tag". Specifically
----:com.apple.iTunes:CONDUCTOR.

It is referenced here: https://picard.musicbrainz.org/docs/mappings/

I don't have any useful experience with tag editors, perhaps yours has an option to use this form ?

I can add this conductor tag using AtomicParsley, as follows:

AtomicParsley 'MyTrack.m4a' --rDNSatom "The conductor name" name=CONDUCTOR  domain=com.apple.iTunes

AtomicParsley refers to this type of metadata as "the reverse DNS format", I don't know what others call it.

Perhaps you can find a way of manipulating your new collection accordingly.

I use mp3tag. I will check whether mp3tag could convert in this format.

[mrw]

So the CONDUCTOR tag, although correctly tagged and visible in mp3tag and TagScanner, is not recognized.

Does anyone understand what is going on?

iTunes does not support a Conductor tag, so any tagger that adds one must be somewhat "unofficial", I suppose.

I see that Mp3tag does, today, use an '@con' atom: https://help.mp3tag.de/main_tags.html

But I don't think that was always the case. This post (from 2011) suggests that it was, then, using a "reverse DNS format tag":
https://community.mp3tag.de/t/conduc...p4-files/12620

When I view my MP4 files in a hex editor, I see that MP3Tag writes a com.apple.iTunes atom having its name property set to CONDUCTOR.

So, I guess what's going on is the presence and development of different ideas of how to do it.

[mherger]

I am using piCorePlayer with integrated LMS on a RPi 3 B+.

I am not familiar with the LMS code. Can I find the source file on the RPi and change it myself??

pCP is a bit peculiar: the files are only linked from an image. You'd have to delete the link and replace it with the actual file, then edit that file.

Feel free to send me a sample file so I can give this a try. Your research seems reasonable, and easy enough to do a quick test.

https://www.dropbox.com/request/T3RctyzGgNg0oFDubq6a

[schup011]

pCP is a bit peculiar: the files are only linked from an image. You'd have to delete the link and replace it with the actual file, then edit that file.

Feel free to send me a sample file so I can give this a try. Your research seems reasonable, and easy enough to do a quick test.

https://www.dropbox.com/request/T3RctyzGgNg0oFDubq6a

Thanks a lot! I guess you mean sending you a sample .m4a file with the "CON" tag. I will do that tonight.

Edit: Managed to do it already now. So the file is on the Dropbox. The conductor tag should display "Zubin Mehta" if recognized properly. I checked within this file that mp3tag has written the ©con tag.

[schup011]

iTunes does not support a Conductor tag, so any tagger that adds one must be somewhat "unofficial", I suppose.

I see that Mp3tag does, today, use an '@con' atom: https://help.mp3tag.de/main_tags.html

...


So, I guess what's going on is the presence and development of different ideas of how to do it.

You are right, it is difficult to find the "official" specification of the tag fields.

I had the simplistic approach that one of the commonly used tagging programs like mp3tag knows it better than I do :-). In fact, if you look at the main_tags table, the "©con" is the only tag of the more often used ones that is not part of the mapping list I mentioned. All others, also a couple of "©xyz", are mapped inside LMS.