I want to edit m4a file's ©prf tag value, but I can't read or find ©prf tag by mp3tag. kid 3 can read ©prf tag. so I am sure my m4a file has ©prf tag. is it a bug of mp3tag?
You can have a look here:
to check what kind of m4a ©abc fields are already available.
What exactly would ©prf contain?
Update with some more detailed information:
(thanks for the hint to @ohrenkino)
So ©prf would be the fieldname for performers .
This atom is currently not supported by Mp3tag up to version v3.28e.
There are a wide variety of tags that mp4 files could have. Most are based on what Apple included in their software. ©prf is for performers
Here are a somewhat exhaustive list QuickTime Tags
MP3Tag don’t include it afaik, but @Florian may device to add it.
Thanks for reply, ©prf is "performer". mp3tag doesn't seem to support reading ©prf yet. But ©pub is ok. Is there a chance that it will be supported in the next version?
In my experience, ©prf is not very widely supported. In fact, I don't know any app that displays this as Performer (even kid3, referenced in the original post, displays the atom id and not a mapped name). Do you know how this field was added to the files and which apps are currently supporting this?
Mapping ©prf to PERFORMER would result in any existing custom field PERFORMER (which is read and listed by any app that supports flexible tagging via custom fields, e.g., foobar2000) be written as ©prf MP4 atom when saving any changes.
As a consequence, this would result in this field not being visible anymore for apps that don't support the ©prf MP4 atom.
The reason for modifying ©prf is that Roon will read ©prf first. Although PERFORMER can be modified, only the original value of ©prf is displayed in Roon. I tried to map ©prf to PERFORMER, but the modified result is still only written to PERFORMER tag. Is there any other way to modify it by mp3tag?
So if you remove this and only have PERFORMER, Roon will read this field?
No, unfortunately not.