[F] Unknown MP4 atoms are deleted on save


What do you need ITUNESHDVIDEO=0 for?
Isn't it the same as a missing ITUNESHDVIDEO tag?


Hi Dano,

It's a bigger issue than just that I'm afraid... For example see the post higher up, noting that CDEC is deleted...

Another example is the "rate" box... There appears to be an issue where MP3Tag does not read "unknown" first level atoms (read: not itunes styles). This means that if you open the file containing such as tag, and save it, the unread tags are destroyed.

This ITUNESHDVIDEO issue appears to be a play on the above, as MP3Tag does write the "0" value to the file (as shown by mediainfo), however, if you close and re-open MP3Tag, the tag is NOT visible within mp3tag, and saving the file does not write the tag back (as again, checked by mediainfo).

(Note, when I say visible, I mean even within the "Extended Tags" dialog).

I lost hundreds of my "rate" tag due to this bug, and I've been begging Florian to allow that tag to be written so that I can automate it... I'm afraid nothing yet. :confused:


I know all the issues, my question was only what's the use of ITUNESHDVIDEO=0


:slight_smile: For that specific case, no difference. Just stating the issue. :slight_smile:


Still an issue with "e" version.


Bump, as the issue is still present in 2.48.

Tags that are not recognized by MP3Tag are destroyed upon a save (also see this reported here: /t/10052/1

Also, Florian, can you please add first level atom "rate" mp4 (similar to cprt atom) to allow me to reverse the damage cause by the destruction of the tag? I've been waiting 6 months to fix my files. :frowning:


what is cprt?

what app is allowing you to write ratings to mp4? itunes unwisely doesn't seem to support writing ratings to tags. i am trying to get winamp to do this for mp4, so as much info about "rate" and cprt and apps that support them like twonky would be appreciated.


"cprt" is the copyright atom for mp4. mp3tag can write this using the attribute "COPYRIGHT"

"rate" is the ratings tag. The program that I use which uses it is Twonky Media Server. I'm waiting for florian to fix a bug that causes this atom to be deleted if it exists in mp4 files, and hopefully for florian to be kind enough to allow this tag to be written by mp3tag so that I can fix the files that lost the tag.

Note that itunes doesn't write (or read) ratings tag from the file. It always stores it in its database.

Recent versions of atomic parsely support writing this tag, but you have to compile from source, and do one file at a time. :confused:



thx for the info, i shared it with the winamp devs, so maybe they will implement it as well. i def hope mp3tag does too, and as with winamp, i always suggest any app ignore a frame it doesn't understand, rather than delete it. i am still confused as to why mp3tag "reorders" mp4/atom data.

i wonder how or why twonky got into supporting such a non-standard frame? i doubt too many folks out there are compiling parsley code. can twonky write ratings to the file?


Updated to 2.48b... still same issue...

Florian, can you please add first level atom "rate" for mp4 (similar to cprt atom) to allow me to reverse the damage cause by the destruction of the tag? I'm approaching a wait of 9 months to fix my files that had the first level 'rate' atom deleted incorrectly by mp3tag. :frowning:


Still an issue with 2.48d


Hi edrikk,

thanks for your patience (and all the others who are reading here too). I really want to get this fixed (preferable by keeping unknown atoms) but unfortunately fixing this is far from trivial. I've started working on this and hope to have a working solution over the next weeks.

Kind regards



Thank you Florian!

Version 2.48e fixes all of the issues that have been stated in this thread! :smiley:


what is the appropriate data range of values for the rate atom?

is it unrated, and then 0-5 or 0-100 or what? what does twonky do?


Guys, can some one help me with this ratings ?

I am using winamp for storing my music in library and use ratings, and now I decide to start using twonky server for sharing music and video between devices at home, can I save somehow ratings so that server can using this ratings data ?


winamp only saves ratings to tags/files if you check / opt-in to the pref, and even if you do that, it does not work on mp4/atom based files afaik. ratings for those are only in its ML DB.

i think twonky created its "own" standard for such files, and uses its own custom atom for such files, but i have yet to find out what atom it is, and what data range is acceptable. (i don't use twonky)

i would like to know, b/c then i can lobby for winamp to support it, and i am basically singlehandedly responsible for winamp now supporting ratings in files/tags, and the data ranges they use.


Somehow twonky finds a rating in the files that I never set ratings manually.
I found this link http://www.twonkyforum.com/mediawiki/index...Twonky_Database
here we see that m4a format have rating tag, so can i use mp3tag for changing all my tag data to this new tag format, and then manually reset ratings to them ?


I remember one more sing.
Some time ago, when I had to move my audio to another HDD, I made this steps:
First I create db dump in winamp. It creates xml file, so then I use php for replacing paths for all files.
And I don't need to re rate all my music. In xml dump file you can see some thing like this:
So winamp use range 0-100 for rate files.


Оh yeah, i add tag rating = 5 and twonky found all my files )

I was wrong, it was enough to add the comment "rating=5" to all files


i'm not sure how to respond to all that above...

i don't really know twonky or mp4s/atoms very well. i know there is an "official" atom called rating, aka "rtng" but that is for age groups, meaning explicit or not, like G, PG, R, that kind of thing.


afaik, there is no official tag for ratings in the 0-5 stars sense. twonky, afaik, does its own thing, aka "rate"

the xml data dump in winamp is an itunes import/export thing. but the ratings are from the winamp DB, they aren't in the files (meaning, mp4/atom type files).

so have you solved this by putting ratings in comment tags? does twonky support that? that sounds like a separate solution from using a 'rate' atom. and i am pretty sure winamp doesn't support ratings in comment tags.