Windows Explorer and Mp3tag Comment field disagree

Windows Explorer show a random string of characters in the Comment field for some mp3 files (ID3v2.3 UTF-16 format). Mp3tag shows its Comment field as blank for those same files. Told Mp3tag to blank the Comment field, then Save the files. The Comment field display didn't change in Explorer. Ran MP3-Diags.exe tool on those same files. It shows those files as having more than one "COMM size=" field in its ID3v2 Xing header. That seems to cause a string of characters from somewhere in the mp3 file to be displayed as part of the Comment field in Explorer, but as a blank Comment field in Mp3tag. When there is only one COMM size= field in the header, both Explorer and Mp3tag agree on what is displayed in the Comment field. The only way to fix the problem I have found so far is to tell MP3-Diags to delete the ID3v2.3 header, then use Mp3tag or Winamp audio player to manually rebuild a completely new header.

Can a future version of Mp3tag display those mp3 files having this multi COMM size= corrupted header (say by highlighting them in red) so they can be repaired? Better still, have an option to repair this issue in Mp3tag itself?

Are you using iTunes, or have you in the past? Apple has used the comments to contain several of their “proprietary” fields, specifically the normalization info. You can force these to be removed, but you will then lose any of that info in Tunes.

No, my mp3’s come from my ripping my CDs on my Windows machines. Then I used both Winamp and Mp3tag to fill out the ID3v2.3 header. Any errors that are found are fixed using that MP3-Diags tool I mentioned before.

My vehicle’s mp3 player has several restrictions (including things like the number of pixels in the cover art, external vs internal file names, etc), so every field in the header has to be carefully reviewed to work in my vehicle.

Maybe a screen shot of one such file with the extended tag view open could help. Use Alt-T to display it. Perhaps use have Ape or id3v1 tags conflicting this?

Do you refer to the comment-field in the tapanel or did you use the extended tagview (ALT-t) so see all tag-fields.

The MP3-Diags tool shows multiple COMMENT fields for this ID3v2.3 UTF-16 file (there are no ID3v1 or APE fields present). Windows Explorer display the COMMENT string it sees (I'll call it String1). Mp3tag will display an alternate COMMENT field (I'll call that String2) in its normal display window . In Mp3tag, the Alt-T tag feature shows the COMMENT field as containing String2, and another field call COMMENT COMMENT that contains String1.

The MP3-Diags tool does not indicate which string comes first, but I assume Windows Explorer will display the first string it finds in the mp3 header. (Note: String1 may be the combination of a String0+String2 combined together?) Given a choice, I would prefer Mp3tag to display the same COMMENT field as Windows Explorer does. I would also like to see Mp3tag to flag mp3 files that contain this corrupted (my opinion anyway) header information, so that I can manually fix the mp3 header.

The ID3 standard allows multi-value fields - which are several fields of the same type. So there is no corruption.
MP3tag shows all comment fields - what the Windows Explorer apparently cannot do. The idea to emulate the short comings of other programs cannot be the solution IMHO.
You can check files for fields that you do not want like this:
load all the files that you want to inspect,
select them all,
Press Alt-T to see all the tag fields in all of the files.
You could then filter for a file that has the field COMMENT COMMENT with
%comment comment% PRESENT

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There is no "normal" display window. I think you are referring to the so called tag panel. There is only a standard view with tag-fields that are presumed to be wanted by most persons. You can add or delete any tag field from this view because it is completely configurable. So adding a field with the name "COMMENT COMMENT" will also show you this tag field in the tag panel.

I have created a pdf document to highlight what mp3tag is doing, but since I don't know how to upload it, I will describe what it shows.

I have Windows Explorer displaying 2 files, one original mp3 file and another file that started out as an exact copy Windows made of the original file. Windows now shows the Comments field of the original file as the value 'K. 271', and the copy showing the value of '410EE206' in the Comments field, when in the tag panel display I performed a COMMENT set to < blank > for that file, then performing a Cntl-S save tag.

The middle display of my pdf document show the original unmodified file having a COMMENT of 'K.271', a COMMENT COMMENT field displaying another string of characters, as a result of using the Alt-T command in Mp3tag.

The bottom portion of my pdf document shows the modified results after performing a COMMENT set to < blank >, then saved. The tag panel display shows the COMMENT field blank, the Alt-T display shows no COMMENT field, and the COMMENT COMMENT field still displaying the same string of characters as the original file. As I indicated before, Windows Explorer is displaying the character value 410EE206 in the Comments field, which is not what the former COMMENT field was, nor what the current COMMENT COMMENT display is with the Alt-T, but what is displayed in the Alt-T field called COMMENT CDDB DISC ID.

So when you have both a COMMENT and COMMENT COMMENT field (according to the Alt-T display) and you tell Mp3tag to delete the COMMENT (set it to < blank >), it removes the Comment field (according to all the Mp3tag displays), but now sets the comment field to none of the original comment field values, but to the COMMENT CDDB DISC ID field value as displayed in the Alt-T display. So when Windows displays the contents of the mp3 header, it displays what Mp3tag updated in the mp3 ID3v2.3 header.

Would you not call that a bug?

Perhaps posting a screen shot of your Alt-T extended tags display would help now? Or share the file(s) in question so that others can look into the metadata and provide you with feedback? It is very difficult to follow the way it is described above.

No. Or if at all - then in Windows Explorer.
There is a peculiarity with the field COMMENT in the ID3 standard.
It allows to create such COMMENT plus extra name field and still treat them as COMMENT field.
e.g. iTunes used them for COMMENT ITUNNORM.
see more in this thread:

So there is still no bug.
I would find it much more interesting who (or which program) created those extra comment fields that puzzle you. i would remove them if there is no real need for the fields.

As you noticed: MP3tag shows (contrary to the Windows Explorer) all comment fields. It is the non-tagging program Windows Explorer that causes your problems.
You have now all the tools at hand: you know that there may be more than just plain COMMENT fields, you know (now) the extended tags dialogue, you can pinpoint which fields you want to treat - everything much better than that what the Windows explorer offers you.

Mp3tag Display.pdf (202.6 KB)

So as explained previously, mp3tag is showing the first available COMMENT field in the main display. On the second file selected, there is no standard COMMENT, so the next one up is COMMENT CDDB DISC ID. If you went ahead and deleted that field as well, the window would then display the contents from COMMENT COMMENT.

Just an observation, but I have never seen the field COMMENT COMMENT used as a standard in the past. And I have purchased from many sources including iTunes. I would suggest this was likely the result of some other change made to these particular files after the fact. I would filter to find all files that have the field COMMENT COMMENT present, then decide which needs to be kept. Format the standard COMMENT field with the contents that exist, then delete the incorrect fields. You will then find consistency with your files in Explorer and elsewhere.

COMMENT CDDB DISC ID Is an iTunes field generated when a CD is ripped from within iTunes. It is an ID field used to identify the disc and match the other metadata fields at that time. This field can also be deleted if you wish, it has no other function in iTunes, and definitely not outside of that environment.

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