# \[X\] Can't copy some unusual TRACK tags from MP3 / FLAC to WMA

**URL:** https://community.mp3tag.de/t/x-cant-copy-some-unusual-track-tags-from-mp3-flac-to-wma/17714
**Category:** No Bugs
**Created:** [March 4, 2016, 10:40am UTC](https://community.mp3tag.de/t/x-cant-copy-some-unusual-track-tags-from-mp3-flac-to-wma/17714 "2016-03-04T10:40:10Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![ryerman](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ryerman/32/5285_2.png) [@ryerman](https://community.mp3tag.de/u/ryerman)
#### Post date: [March 4, 2016, 1:25pm UTC](https://community.mp3tag.de/t/x-cant-copy-some-unusual-track-tags-from-mp3-flac-to-wma/17714/4 "2016-03-04T13:25:20Z")

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> [@zerow](#):
>
> So the bug is: it can be copied, but to MP3 and FLAC; but such an attempt on a WMA file will spit out an error saying, that it cannot be opened for writing

This is not a bug, but the result of an Mp3tag feature.

WMA files use ASF (Advanced Systems Format) tags.  
see here:  
[https://msdn.microsoft.com/en-us/library/wi...v=vs.85%29.aspx](https://msdn.microsoft.com/en-us/library/windows/desktop/dd757536%28v=vs.85%29.aspx)  
[https://msdn.microsoft.com/en-us/library/wi...v=vs.85%29.aspx](https://msdn.microsoft.com/en-us/library/windows/desktop/dd743066%28v=vs.85%29.aspx)

My understanding is this:

ASF tags support both Track and TrackNumber.  
Track is 0-based and included for legacy reasons. (ie back-wards support)  
TrackNumber is 1-based.  
Mp3tag writes both.

You may ask, "How does Mp3tag write those tags?"

Only the developer knows for sure, but my observations suggest this:  
Whatever number is entered by the user becomes TrackNumber.  
Track is calculated by substracting 1 from the integer portion (the part before the decimal) of TrackNumber.

This means that you may only enter any decimal number ~~greater than~~ greater than or equal to 1. [EDIT]  
Anything else will cause the warning you have seen.  
This allows the feature of writing both Track and TrackNumber.

For example:  
If you enter 1, then TrackNumber = 1 and Track = 0  
If you enter 1.12345, then TrackNumber = 1.12345 and Track = 0  
If you enter 1.9, then TrackNumber = 1.9 and Track = 0  
If you enter +1.9, then TrackNumber = +1.9 and Track = 0  
If you enter +300.9, then TrackNumber = +300.9 and Track = 299

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