Can't add more than one WWW tag info WMA file. Is it correct?

[kanda]

Extended tags dialog allows me to enter arbitrary amount of WWW tags.

But only the last entered tag survives after save.

Is it correct for WMA file?

mp3tag is concurrent development: v3.31k, Nov 7 2025

[ohrenkino]

I see the www field just as I saved it:

Where/which program does not show the data as you expected it?

PS: current version is 3.32 ...

[kanda]

@ohrenkino

PS: current version is 3.32 ...

Thank you for noting, I have missed the update. I can reproduce the issue in 3.32 too.
Extended tags dialog before entering WWW tags:

I had added 2 WWW tags, “4” then “3”, but had not clicked OK yet:

I clicked OK, ext. tags dialog is closed, and I reopened it again:

Only WWW = “3” survived Tried a few (5-6) other wma files, the same issue.

May I have missed something?

[ohrenkino]

Between clicking OK (screenshot 2) and reopening the extended tags dialogue (screenshot 3) did anything else happen like saving tags again?
(because my file, even a day later still looks like initially shown: 2 WWW fields).
I suspect that some other manipulation happens in between that saves the tag again but takes only the data from the one of the WWW fields, e.g. if there is a column that shows the contents of %www% but not $meta_sep(www,\\) which will show only 1 www field.

[poster]

I can confirm this behavior that only 1 multivalue filed for www remains after saving. It happens hear with wma-files but also with mp3-files.
The hex-editor shows me that there is only 1 www-field.
In tests with a wma-file always the last added www remained, with mp3-files it changed sometimes.

I does not happen with flac-files here.

It is not restricted to the www-tag-field.
Also also tried it with a user-defined field TEST and get the same issue.

Edit:
I also happens with wav-files.

With the user-defined field TEST I could only reproduce it with wma-files so far, not mp3 and also not wav.

[ohrenkino]

Thank you for testing.
Apparently, I was not alert enough and did my tests on an m4a (not wma) file.
So please ignore all my comments.

[kanda]

@poster

It happens hear with wma-files but also with mp3-files

Given that, I also tried mp3 files. Indeed,
only 1 (one) WWW tag value remains in mp3 file. I didn’t notice that

Custom tag may have multiple values in mp3 file, but again, only 1 (one) in WMA file

[Florian]

WMA tags are a little special when it comes to supporting multiple values. There is a list from Microsoft that details which fields actually support multiple values

Attributes with Multiple Values (Windows Media Format 11 SDK) - Win32 apps

However, not all are supported by Mp3tag (e.g., the WM/UserWebURL field is a binary field that currently isn't).

For a complete list refer to the official Mp3tag mapping, where supported fields have an entry at ASF/Windows Media, e.g., WM/AlbumArtist.

Tag Field Mappings – Mp3tag Documentation

---

As for support for WWW in ID3v2, it internally maps to WXXX which is defined as

This frame is intended for URL links concerning the audio file in a similar way to the other "W"-frames. The frame body consists of a description of the string, represented as a terminated string, followed by the actual URL. The URL is always encoded with ISO-8859-1. There may be more than one "WXXX" frame in each tag, but only one with the same description.

This means, you can only one WWW field to an ID3v2 tag (e.g., in MP3s or WAVs ID3 chunk) with an empty description. If you intend to use more than one of such fields, you need to use a different description.

In Mp3tag, such descriptions can be added as part of the field name, e.g,
WWW DESCRIPTION = Field contents

[kanda]

@Florian

As for support for WWW in ID3v2, it internally maps to WXXX which is defined as

There may be more than one "WXXX" frame in each tag, but only one with the same description.

Thank you for explaining. The entity ID3v2 frame is new for me: Mp3tag documentation does not mention it. Could you, please, clarify, how do ID3v2 frame, ID3v2 tag, and Mp3Tag field correspond to each other?

@Florian

In Mp3tag, such descriptions can be added as part of the field name, e.g,
WWW DESCRIPTION = Field contents

Well, but

1. most important, it looks like keeping data in custom tags, what looses web url semantic. Is WWW DESCRIPTION more web url than, say, WWW2 = https://... or ABC 1 = https://..., ABC2 = https://...?
2. The description is lower-case prohibited.
3. WWW DESCRIPTION tag(s) (frame(s)?) can not be mapped into file list column, because %www% does not catch them.

Curiously, I managed to get, only with Mp3tag and Windows Explorer, double WWW tag (frame?):

So multivalue WWW tag (frame) is technically possible. It gets alone again after changing any other tag, for example, YEAR:

Would it be more correct not to overwrite them?

@Florian

However, not all /WMA tags/ are supported by Mp3tag (e.g., the WM/UserWebURL field is a binary field that currently isn't)

Well, but single WWW tag is saved by Mp3tag. Which WMA attribute is used for that? This is not documented in Mp3Tag.

[Florian]

@kanda

Could you, please, clarify, how do ID3v2 frame, ID3v2 tag, and Mp3Tag field correspond to each other?

It does mention it at Tag Field Mappings – Mp3tag Documentation, where you can see how Mp3tag's field names are mapped to ID3v2 frames. ID3v2 tags consist of ID3v2 frames.

See https://id3.org if you want to learn more.

@kanda

WWW DESCRIPTION tag(s) (frame(s)?) can not be mapped into file list column, because %www% does not catch them.

You can use %WWW DESCRIPTION% if you really want to use those.

@kanda

So multivalue WWW tag (frame) is technically possible. It gets alone again after changing any other tag, for example, YEAR:

Yes, it's technically possible. However, I don't want to go into commenting on your experiments with multiple WWW fields. I think I've explained Mp3tag's behaviour in my previous post.

@kanda

Which WMA attribute is used for that?

It uses the field name without any mapping, i.e., WWW.

[kanda]

@Florian

@kanda

The entity ID3v2 frame is new for me: Mp3tag documentation does not mention it.

It does mention it at Tag Field Mappings – Mp3tag Documentation, where you can see how Mp3tag's field names are mapped to ID3v2 frames

Surely I can not. The document contains a mapping — but to ID3v2… well, You-Know-What.
The term frame never appears at all. The document happily avoids naming what exactly Mp3tag is mapping to. So does every other document in the Mp3tag Documentation.

@Florian

However, I don't want to go into commenting on your experiments with multiple WWW fields. I think I've explained Mp3tag's behaviour in my previous post

I have noticed that you are not so principled about ID3v2.3 spec conformance when it comes to writing multivalued TCOM, TPE1, TXXX and other ID3v2.3 frames, or when writing letter values to the TBPM frames, and possibly other spec violations.

So you really could not write to me as if I had, um, suggested something improper.

Since some issues raised in the discussion remain unaddressed, I’ve decided to file them as separate bug reports.

Thank you for your time.

[Florian]

@kanda

Surely I can not. The document contains a mapping — but to ID3v2… well, You-Know-What.
The term frame never appears at all. The document happily avoids naming what exactly Mp3tag is mapping to. So does every other document in the Mp3tag Documentation.

From what you write, I think you now understood that what I mean by how they are mapped to the internal structures of the different tag formats I'm referring to ID3v2 frames for ID3v2.3 and ID3v2.4.

@kanda

I have noticed that you are not so principled about ID3v2.3 spec conformance when it comes to writing multivalued TCOM, TPE1, TXXX and other ID3v2.3 frames, or when writing letter values to the TBPM frames, and possibly other spec violations.

Are you suggesting that I'm doing something improper? I surely hope that this doesn't turn into something nasty, only because Mp3tag doesn't behave in the way you like.

@kanda

So you really could not write to me as if I had, um, suggested something improper.

I don't think I did that, sorry if that came around the wrong way. I've simply outlined Mp3tag's behaviour with regard to multiple WWW fields in WMA and MP3.

[kanda]

@Florian

From what you write, I think you now understood that what I mean by how they are mapped

Sure yes, for now. But it would save me a great amount of time if Mp3tag had documented that

• Mp3tag tag fields map to ID3v2 frames, not You-Know-What

Btw, the same silence in [Tag Field Mappings] is about other tagging formats. Mp3tag tag fields map to what in WMA, map to what in MP4 and so on.

@Florian

@kanda

writing multivalued TCOM, TPE1, TXXX and other ID3v2.3 frames, or when writing letter values to the TBPM frames

Are you suggesting that I'm doing something improper?

Absolutely proper I just believe, that enabling multivalued WXXX is even more proper.

@kanda

Is WWW DESCRIPTION more web url than, say, WWW2 = https://... or ABC 1 = https://..., ABC2 = https://...?

I verified and can confirm, WWW description and WWWdescription syntax map to WXXX frame with corresponding description