error when using user defined tag

[lnjustin]

I'm trying to write a user-defined tag that will record the ID used by Apple Photos in its database. An example ID is "aqqYIEgwQCS+MZY9JfxTjA". so just text. My config file is:

%Image::Exiftool::UserDefined = (
   'Image::Exiftool::XMP::xmp' => {
      applePhotosID => { Name => 'applePhotosID' },
   },
);

1;

When I run this command: /usr/local/bin/exiftool -config customConfigPath -xmp-xmp:applePhotosID=itemID

I get this error:
error "Photos got an error: Unrecognized character \\xE2; marked by <-- HERE after    <-- HERE near column 2 at /Users/xxxxxxxx/Pictures/Exported/customConfig line 2.
Warning: Tag 'xmp-xmp:applePhotosID' is not defined
Nothing to do." number 1

Help?
Also, while I'm here, can you confirm this is the write type of tag to use (XMP) for this purpose?
And, will this be able to write a user defined tag no matter the type of file (video or photo)?

[greybeard]

You are getting that error because you have back-tick characters instead of single quotes on both lines 2 and 3

%Image::Exiftool::UserDefined = (
   'Image::Exiftool::XMP::xmp' => {
      applePhotosID => { Name => 'applePhotosID' },
   },
);

1;

[Phil Harvey]

See this stack exchange thread to fix your quote problem.

- Phil

[lnjustin]

Thanks. That fixed it. Now i can't figure out how to just read back out the string value of the tag. If i use -xmp -b -xmp:applePhotosID, it spits out a whole binary file (and if i leave out the -b option it tells me to use -b to extract). And i can't even see the applePhotosID information in the binary file.

I tried switching to IPTC:
%Image::Exiftool::UserDefined = (
   'Image::Exiftool::IPTC::ApplicationRecord' => {
      240 => {
         Name => 'applePhotosID',
         Format => 'string[0,64]',
      },
   },
);

1;

And calling with just -applePhotosID=itemID. But i get
Warning: Tag 'applePhotosID' is not defined
Nothing to do." number 1

It's certainly reading the config file correctly, since it notified me of the syntax problem. What am i doing wrong then?

[Phil Harvey]

The devil is in the details.

The capitalization of "ExifTool" is wrong in 2 places.   Try this:

Code Select Expand

%Image::ExifTool::UserDefined = (
   'Image::ExifTool::XMP::xmp' => {
      applePhotosID => { Name => 'applePhotosID' },
   },
);

1;

[lnjustin]

Ahh! Details. Thanks. That worked like a charm now. With the only thing being that i was running this on a .heic file. Fortunately, you added support for that format fairly recently, so i was able to update ExifTool accordingly. It looks like with this new version i have to add the option -overwrite_original whereas previously i didn't. That threw me a bit but it seems to be working as expected with that option now. Thanks!!

[Phil Harvey]

Why do you say that you need to use -overwrite_original?  ExifTool should have always preserved the original file whenever anything in the file is changed.

- Phil