[AF] iTunes Sound Check bug.

MP3tag seems to remove the trailing space from the iTUNNORM tag, making iTunes think it needs to re computed.

I believe the bug is located in actions that use the _TAG tag, to adjust all the tags at once instead of individually. do you think you guys could exempt iTUNNORM from the "_TAG" selector?

tl;dr if you remove trailing spaces, and the _TAG selector to select all tags, it will corrupt iTunes's Sound Check data, which is stored in the ITUNNORM tag. In order to solve this issue, you should exempt iTUNNORM from the _TAG selector. there are literally no downsides to this, as the iTUNNORM tag contains binary data and should never be subject to data manipulation in the first place.

Hardly a 'bug', the tag you refer to is proprietary metadata for iTunes and other Apple devices and not part of any official ID3 specification so how or why should any third party application be expected to 'know' how to handle it, or not as the case maybe.

that doesn't mean it's not damaging data stored there, and I don't get the attitude?

There are two options, we can each individually set our scripts to ignore Sound Check data, which will be a total pain in the ass, we''ll get cryptic messages of bugs and problems in the forums, and only a select few that saw this post or experienced the bug themselves will be able to answer, or we can go straight to the source and make an exception for the iTUNNORM tag in mp3tag itself, saving everyone this trouble.

1. You can avoid this, whenever there is the need to trim left tag-field names, ...
by replacing the leading space character in all iTUN* tag-field names with a replacement character.
Afterwards, when using _TAG all tag-field names has been trimmed, then revert the replacing.

  1. You can avoid this, whenever there is the need to trim left tag-field names, ...
    after the first step of using _TAG and trimming all tag-field names...
    do a second step to insert one leading space character in all iTUN* tag-field names.


It seems to me that I was wrong in understanding the given situation.
'marcusj0015' has put the focus on the tag-field value, but not on the tag-field key name.

But the idea, to preserve leading or trailing spaces in the tag-field value by substitution the space characters with a different unique character should work.

How to rename a tag-field key name using an action, read there ...
Help with changing FLAC field name, please.


No attitude, just a simple statement of fact.

This is a 'use case' issue not a global MP3Tag issue, so has to be rectified by the user for this particular scenario.

Not every MP3Tag user is also an iTunes user and not every iTunes user is also a MP3Tag user, and the number of simultaneous coincidences where a MP3Tag and iTunes user is wanting to trim trailing spaces from all tags is maybe in the order of ... well, probably just you. :slight_smile:

So it is not a program 'bug' simply because a program bug is;
Unexpected or erroneous behaviour under a given set of circumstances that affects all users equally and can be repeated during testing.

There is no way that a developer of any kind of 'tagging' software can test every possible combination of functions and media players that could exist, so there is always going to be unforseen circumstances.

Lol, this should be no itunes bashing.
But if you know you have tag fields which need trailing spaces, you should probably not apply an action which removes trailing spaces from all tag fields.
And for other itunes users who don't know their tag fields, they should probably apply no action at all which changes all tag fields.

Actually I wasn't aware that the ITUNNORM tag contained/required a trailing space, or that my action removed it from that tag, I was under the impression _TAG only applied to tags that contained strings for some reason. I thought it was an iTunes bug and contacted them about it, and I thought i'd tell you guys about it after they discovered the bug.

I understand you can't test every possible combination, especially when it comes to user created actions, I get that. hence my posting of the problem, I'm literally here just to keep future users from suffering the same strange issues I encountered.

Welp, if you're not going to do that, All I can do is hope any future users expierencing sound check corruption that use mp3tag actions to remove spaces find this thread and can rectify their issues easily compared to all the trouble I had.

Also, the Apple Support Engineers said he would make sure iTunes ignored missing spaces in the iTUNNORM tag, in the version coming out after iTunes, so for future Googlers, update iTunes and it SHOULD work, at least that's what Apple says.

If it doesn't get fixed, or work, could you not just adjust your Trim Action to replace the character in the ITUNESNORM tag?

Are you speaking about trailing or leading spaces? Can you please also refer to the post from Apple Support?

Kind regards

There was no post, I filed a bug report with them; it's private, I can take a screenshot of it if you want?

No, if it was a private conversation I'd prefer to keep it as such.

Can you give a comment on the first question, are you speaking about trailing or leading spaces?

Kind regards