Bug #779

Crash with unknown lens tags in DNG

Added by Moritz Moeller over 10 years ago. Updated over 5 years ago.

Target version:
Start date:
15 Jul 2011
Due date:
% Done:


Estimated time:
1.00 h


This is a crash in Darktable ( when DNGs with unknown lens tags are read via exiv2.
The DT devs have confirmed the bug is present in exiv2 0.19 and 0.21.

The resp. thread from the Darktable mailing list is here:
A DNG to replicate the crash is here (GH2 folder):

Related issues

Related to Exiv2 - Feature #543: make exiv2 respect makernote offset that Microsoft WIC tools introduce when it edits photosClosed




Updated by Andreas Huggel over 10 years ago

It appears that the makernote in the attached DNG is corrupted. Exiftool says

Warning                         : [minor] Possibly incorrect maker notes offsets (fix by 17080?)

and has an algorithm to guess the correct offset. Exiv2 doesn't, it uses the wrong offset to get (among others) the lens type which results in garbage output as reported.

As a workaround, check if Exiftool can fix the makernote by writing the guessed offset back into the image.
I'll consider adding a similar guessing algorithm to Exiv2 to handle such cases.



Updated by Robin Mills about 6 years ago

  • Target version set to 53

Updated by Robin Mills over 5 years ago

  • Category set to image format
  • Status changed from New to Assigned
  • Assignee set to Robin Mills

This issue has been in the database for 4 years and nobody else has requested progress with this matter. So, unless you engage to persuade me to keep this matter alive, it will be closed on April 30 as “no longer needed/wanted.


Updated by Robin Mills over 5 years ago

  • Category changed from image format to withdrawn
  • Status changed from Assigned to Closed
  • % Done changed from 0 to 100
  • Estimated time set to 1.00 h

Updated by Robin Mills over 5 years ago

  • Target version changed from 53 to 0.26

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