ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: mrdpenguin on February 07, 2012, 08:35:16 PM

Title: XMP Restructured When Copying
Post by: mrdpenguin on February 07, 2012, 08:35:16 PM
Hi,

I'm new to this tool. I'm trying to write the filename to the XMP IPTC title field. I've been able to do this using the following command with the example configuration file:

exiftool.exe -config <location of config file> -BaseName>XMP:title <directory of photos> -ext xmp -r -overwrite_original_in_place

However, I've noticed that if I do a difference of the XMP file before running exiftool and after running exiftool the files are completely different. I had just expected the title field to change. I have several thousand photos in Photoshop Lightroom that I'd like to update the title field with the filename. I've done the following steps:

1.) Write metadata to XMP from Lightroom
2.) run the above EXIFTOOL command
3.) Read XMP metadata from file in Lightroom
4.) Save back XMP metadata to file from Lightroom

Even after doing this a difference on the original and final XMP files are completely different. I haven't noticed any problems with Lightroom reading back in the XMP data even though the order of all the XMP fields changed, but it makes me a little nervous. I was wondering why exiftool doesn't just leave the XMP information in the same place and only update the desired field? Why does it reorder everything? Should I be concerned that this reordering will upset Lightroom? I haven't seen any problems yet, but I'm still concerned especially since I'm tackling so many photos.

Thanks!
Title: Re: XMP Restructured When Copying
Post by: BogdanH on February 08, 2012, 03:17:58 AM
Hi,

I'm no expert on this, but what for are you using config file? That is, without knowing what's inside config file, it's hard to know what's happening... and then, what is -BaseName for?
Anyway, if I uderstand what you're trying to do, I would do something like this:
exiftool -filename>Xmp:Title -r -overwrite_original -ext xmp <directory of photos>

Anyway, maybe it's better to wait for Phil -he knows this config stuff  :)

Bogdan
Title: Re: XMP Restructured When Copying
Post by: Phil Harvey on February 08, 2012, 07:12:16 AM
This is related to FAQ number 13 (https://exiftool.org/faq.html#Q13).

Basically, the structure of the XMP is (unfortunately) extremely flexible, and XMP containing identical information will look different when stored by different applications.

The actual metadata stored in the XMP should not change with your command (other than the Title tag), regardless of how it is restructured.

- Phil
Title: Re: XMP Restructured When Copying
Post by: mrdpenguin on February 08, 2012, 12:41:40 PM
Thanks Phil. So I take it there is no exiftool switch to tell it not to restructure all the XMP and just rewrite the title field?

I realize that I'm probably getting a little paranoid at this point, but I'm somewhat new to all of this and just want to make sure I don't somehow subtely damage my lightroom catalog when reading back the metadata after maniupulating it with exiftool and not realize it for weeks later.
Title: Re: XMP Restructured When Copying
Post by: Phil Harvey on February 08, 2012, 12:50:22 PM
Quote from: mrdpenguin on February 08, 2012, 12:41:40 PM
So I take it there is no exiftool switch to tell it not to restructure all the XMP and just rewrite the title field?

I can pretty well guarantee that there is no application on earth that will do this.

QuoteI realize that I'm probably getting a little paranoid at this point, but I'm somewhat new to all of this and just want to make sure I don't somehow subtely damage my lightroom catalog when reading back the metadata after maniupulating it with exiftool and not realize it for weeks later.

A valid concern.  But I think if there was an XMP problem like this I would have heard about it by now, given the number of people out there using ExifTool (both directly, and indirectly via other applications that use ExifTool) in their LR workflow.

- Phil