Unable to remove/write tags for FLAC files with 16 MB+ embedded cover

[enve]

I've recently had several .flac files that were tagged with 16 MB+ covers; which I've attempted to edit with Mp3tag; however Mp3tag won't load the cover for such file (tags are loaded alright).

That would be acceptable however attempting to remove all tags or just edit any tags just results in "Cannot write file" error message. It would be nice if this could at least be fixed, to be able to remove the invalid tag block - though I guess since the metadata area does not shrink when editing with Mp3tag, it may not be possible?

I could view the tags and the cover in other apps, using Icaros as property handler it displayed fine in explorer as well. If this is to be closed as won't fix, I understand but it would be really great if I didn't need to re-encode such files.

[ohrenkino]

See also this thread:

Cannot embed large size cover image(s) for FLAC

When writing tags for FLAC files, the program simily fails if the cover image file that is bigger than about 20mb. I have been wrestling with the cover image which happens to be 35.6mb (PNG file), and the program tells me it cannot write the tag. I reduced the size to 24mb (JPG file) and it still fails to write the tag. Is this limitation of FLAC tag structure? ....My guess is that not many people are that insane enough to put ultra high quality cover art files, but it would be great if this …

It looks to me as though some other program wrote an invalid FLAC tag.

[enve]

Yeah I'm aware of the limitation with the flac file format; but imho not being able to remove such block without re-encoding externally is a bug in Mp3tag to me. I'm not looking to have 20 MB covers in my files, quite the opposite.

Funny that the cover loads with other libraries though.

[ohrenkino]

I would investigate how the invalid falc tag got written in the first place and then see if that step can be revoked at the source or left out in the future.

Here is a thread / post that gives a hint about another program that may help you:

Problems Cover Art FLAC files

Yes, removal of padding (or at least resizing it to something that makes sense) is on my internal list of things to improve for Mp3tag. Until then, you can create this workaround using metaflac.exe (you can download it from the FLAC website, look for flac-1.3.2-win.zip). In Mp3tag, define a user-defined tool via Options → Tools, and name it, e.g., FLAC remove padding, put the path to metaflac.exe and use the parameters --remove --block-type=PADDING --dont-use-padding "%_path%" If you want to …

[Florian]

FLAC has a limitation of ~16MB because the length field of the metadata block can only hold numbers up to 24bit.

The workaround via metaflac linked to above might work, but I can't verify myself. If you like, you can send me one of the offending files.

Also, how did you end up with covers exceeding the possible size? How can I create those files myself?

[enve]

So, upon your inquiry "how", I've checked the source of the tagging app that caused to generate such file and it just ignores the spec and looks like other apps that read it do too. Again, I'm just asking to be able to remove such blocks instead of ending up with an error.

As we know:

RFC 9639: Free Lossless Audio Codec (FLAC)

But in the PICTURE block of the offending flac file the size of picture data is 0x011231F0 which corresponds to the 17.1 MB cover that follows. I can send you such file for testing but I'd prefer to not share publicly as its copyrighted.

[Florian]

@enve

I've checked the source of the tagging app that caused to generate such file and it just ignores the spec

I'd like to know the name of and an URL to this app and if you already reported the issue.

@enve

Again, I'm just asking to be able to remove such blocks instead of ending up with an error.

Yes, I know -- I'm just not sure if it's worth the effort from my side. I don't consider this a bug in Mp3tag, but more of an inconvenience that's (to my knowledge) currently only affecting you.

Have you tried removing the erroneous block via metaflac as outlined above?

[enve]

@Florian

I'd like to know the name of and an URL to this app and if you already reported the issue.

I've sent you both the file and the url in a PM, hope that's okay.

@Florian

Have you tried removing the erroneous block via metaflac as outlined above?

Yeah, metaflac won't remove the PICTURE block if it's above 24bit size.

@Florian

Yes, I know -- I'm just not sure if it's worth the effort from my side. I don't consider this a bug in Mp3tag, but more of an inconvenience that's (to my knowledge) currently only affecting you.

I understand; well, yeah, it is rather inconvenient and I was hoping this could get fixed in the future but I get that this is more of an edge case and not a bug that would be affecting most of the users.

[MotleyG]

@enve

@Florian

I'd like to know the name of and an URL to this app and if you already reported the issue.

I've sent you both the file and the url in a PM, hope that's okay.

Kind of cryptic that you are asking for support here to use mp3tag to help fix this issue, but aren't willing to share with the community what program you were using that ignored the spec. Sharing information is how we can help others that may come across this thread as they search for solutions.

[Florian]

I'm not going to add a workaround for this.

The software used to create this is clearly broken, and the time I'd need to address the symptom is of much less benefit compared to addressing the cause of the issue.

[enve]

Thanks for the statement regarding this, I understand.

[LyricsLover]

@enve

I've checked the source of the tagging app that caused to generate such file and it just ignores the spec...

You could try to open an issue at the source.
This way every user of your "tagging app" would benefit from a fix at the source and no more causing out-of-spec modifications.