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TechnikTobi / little_exif

A little library for reading and writing EXIF data in pure Rust.
Apache License 2.0
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TumbsPlus does not read or write exif data with some files written by Little Exif #29

Closed mschnell1 closed 1 month ago

mschnell1 commented 1 month ago

When I have Little Exif work on a JPG file and it for some reason does not decently detect EXIF data (either because there are none or due to issues described in #28 ) ThumbsPlus does not show any Exif for that file, eve if I pushed ImageDescription onto in. (I tested also pushing Artist but no change). Windows Explorer "Details" does correctly show the ImageDescription string as "Titel" (and funnily also as "Betreff" - which might be a hint...) (More fun: ThumbsPlus seemingly denotes "Title" to something else and uses "Comments" for Image "Description". ThumbsPlus does not provide any error message when reading the file. But when I try to set an Exif Value (e.g. "Artist" <aka "Creator" in ThumbsPlus>), I do get an error message: 

unable to update XMP: 
error #000000ce,
bad IFD offset.

Of course I can't know if the problem is with ThumbsPlus or with Little Exif. Some kind of incompatibility. :(

TechnikTobi commented 1 month ago

Still working on the encoder, so I can't tell yet. However, I have a question: What about images that are processed fine by little_exif? I presume that the Windows Explorer shows everything as you'd expect, but what about ThumbsPlus? Does it show the edited metadata or still the old one? I'm asking this because of the error message regarding XMP metadata, which is something different but still related. If ThumbsPlus relies only on XMP then you should see the unedited data - this would also explain why no ImageDescription gets displayed (as TP would look in the wrong place in this case).

mschnell1 commented 1 month ago

As far as I tested, filed that do have a bunch of metadata and those are seen in ThumbsPlus and that can be decoded by LittleExif, and I then set ImageDescription to a new string, write the metadata back and then write a new file, those files are processed by ThumbsPlus without a problem and the new ImageDescription is shown and imported in the Database as "Annotation". Both if ImageDescription was not set before and if it was overwritten by Little Exif.

mschnell1 commented 1 month ago

I don't know if this still is relevant. I seem to have found that the files ThumbsPlus does not decode, also result in Errors,when trying to decode Them with Little_Exif.

TechnikTobi commented 1 month ago

Does this problem still persist with the 0.6.0 beta?

mschnell1 commented 1 month ago

It's gotten worse, as with the Beta the Exif of even more files is not are not "verified" and a completely new/empty is created and then ImageDescription is written, which then triggers the problem with ThumbsPlus, as seemingly the format of such a "completely new" Exif content is not compatible with ThumbsPlus, while "updated" Exif content usually works as expected.

TechnikTobi commented 1 month ago

I assume we can close this issue as ThumbsPlus can read the results obtained via 0.6.0-beta3?