Strange behavior when adding cover art in Win7

I have this strange behavior:

After adding a jpg file as cover art to mp3s (typically one CD at a time) they do not show up in Explorer immediately. Sometimes some of them do, sometimes not a single one. But they appear after some days!

If i want to see them immediately, I just have to save them in any other program (like AIMP3) and they show up at once.

Just to clarify: I put the files in an AIM3 playlist, select all, hit F4 (properties) and then just the save button for each file once without changing a thing and violá - here they are...

It's not really a problem, as they normally show up after some days, but it bugs me to not understand what is going on.

Thank you for reading.

I think that W7 still relies on a file per folder called folder.jpg.
So if you export one of the embedded covers to a file with that name, you should see the cover immediately.

Thanks for answering (and so quick!)
Actually, it's exactly the folder.jpg that I embed in the mp3s (I have a folder.jpg in every sub folder of my music library) And no, despite being a folder.jpg there, Explorer doesn't show them immediately. But they appear in all other places, like AIMP3 or 1&1 player or VLC.
Also also thought of the MS Windows Icon Cache and have cleared it and I restored the mp3 file properties to default etc. well actually I've tried everything I could think of. (And read half of this forum hahah... )
For a while i thought it could be my name convention (in particular the "." (period) being the problem:
%track%. %title% or %track%. %artist% - %title% when there is more than one artist on the CD.
a thing.

It looks like a windows problem to me, so perhaps a windows support pages like this one
https://answers.microsoft.com/en-us/windows/forum/windows_7-files/cant-view-album-art-in-windows-explorer-in/59ed52fd-0d9a-495d-9e4f-049be44fd9f1
helps you.

It looks like a windows problem to me, so perhaps...

No it isn't, sorry, but I found the reason for the problem:
I put a mp3 and an identical copy in a folder. Then I assigned a JPG file as cover art to it with mp3tag. It didn't show up in explorer as usual. Then I did the "open in AIPM3 and just save it" thing and like always it immediately showed up. now I opened both files in my editor and ran a compare and - bingo.
MP3TAG writes the reference to the jpg file as "JPEG" when the file actually is a "JPG" without the "E" (see screenshot) After manually changing that in the editor (erasing the "E") and saving the file, it the cover art showed up immediately. That's obviously what AIMP3 does.


Seems to be the cause for the behavior. :slight_smile:

What you've observed is the mimetype part of the ID3v2 APIC frame. This frame is used to store the cover art in the tag.

From http://id3.org/id3v2.4.0-frames 4.14. Attached picture

The "image/png" [PNG] or "image/jpeg" [JFIF] picture format should be used when interoperability is wanted.

From https://www.w3.org/Graphics/JPEG/

The registered MIME type for JPEG JFIF images is image/jpeg

Even if the strange behavior in Windows Explorer is caused by the difference in the mimetype string, I don't think that writing it in a non-standard way is a feasible solution.

FYI, I've checked with Windows 10 version 1803 (the latest) and it's working fine there.