I frequently get mp4 files from friends who strictly use MAC/iTunes.

I've read here that Mp3tag will not write leading zeros in Mp4 tags because the format does not support them. I also read that a custom "track" field was added at some point to accommodate this but then removed because iTunes choked on it.

I am curious then, as to why I have some Mp4 files that HAVE leading zeros in the track numbers and other don't. The ones that do can be written/converted back and forth and they retain the leading zeros, but there are some which will not, even though Mp3tag does not indicate there was a problem writing the data. The only difference I can see between the files is either the encoder or the version of iTunes listed, but even that is not consistent. The tag field ONLY shows "MP4 (MP4)" in both cases.

I have tried deleting the tags completely. Doesn't matter. The ones that can have leading zeros still can and the ones that can't still can't. Can someone explain why this is or if there is a work-around? Would it be possible to give the option of using the custom "track" field or not with a check box?

Few more questions:

- Can an ID3v2 tag be written to an Mp4 file?

- Will there be any support for other file types (.wav .aif, etc.)?
I am able to write tags to these file types in Tag&Rename, and they read fine in other apps, but I have no idea how that application is doing it.

- Will Mp4 be added to the options dialog so it can be checked unchecked for reading/writing?

Thank you for your time. This is a wonderful program that I've only recently discovered and it's already saved me a lot of headache getting things in order!

Unfortunately not. I've never encountered such files and still think that track numbers can be numeric only with MP4.


No


Not at the moment.


No, because it's the only tag format that is supported for MP4.


That's great! Thanks for the feedback

Hey - Thanks for getting back to me. Would you like me to send you one of the MP4 files that accepts leading zeros? Smallest one I have is around 8MB. Please let me know when you have a moment. Thanks again!

Yes, you can upload one file to e.g. http://drop.io and send me the URL to support@mp3tag.de

Kind regards
Florian

Hey - drop.io is going through some changes and no longer allows free uploads. I used sendspace instead. You should have the link in your email now. Thanks!

OK just realized the file I linked you is an m4a. Since it showed up as (MP4) in the tag field, I didn't bother to look at the extension... I guess there's the answer, although I thought they were basically the same with the exception of copy-protection (which this file does not have).

It's a file that contains a Nero Digital tag which supports leading zeros for MP4 files and is displayed by Mp3tag.

Kind regards
Florian

If you have the ability to read it, can it be written via the same method or with some custom settings?