Unable to parse makernotes inside dng file

[Hayo Baan]

I have a batch of dng files that exiftool is unable to parse the makenotes from. This is strange as it is able to read dng files from other batches (with the same camera) just fine. When running exiftool -v -v -v on the file, I do notice a makernote code prefix that is different from other (working) files:

Parsing fine (same camera):

Code Select Expand

  | 39) DNGAdobeData (SubDirectory) -->
  |     - Tag 0xc634 (136482 bytes, int8u[136482] read as undef[136482]):
  |         373e: 41 64 6f 62 65 00 4d 61 6b 4e 00 02 15 14 4d 4d [Adobe.MakN....MM]
  |         374e: 00 00 34 88 4e 69 6b 6f 6e 00 02 10 00 00 4d 4d [..4.Nikon.....MM]
  |         375e: 00 2a 00 00 00 08 00 3b 00 01 00 07 00 00 00 04 [.*.....;........]
  |         376e: 30 32 31 30 00 02 00 03 00 00 00 02 00 00 01 18 [0210............]
  |         377e: 00 04 00 02 00 00 00 08 00 00 02 d2 00 05 00 02 [................]
  |         [snip 136402 bytes]
  | + [DNGAdobeData directory, 136482 bytes]
  | | MakN = MM4.Nikon..MM*.;...0210...................................................[snip]
  | | - Tag 'MakN' (136468 bytes):
  | |     374c: 4d 4d 00 00 34 88 4e 69 6b 6f 6e 00 02 10 00 00 [MM..4.Nikon.....]
  | |     375c: 4d 4d 00 2a 00 00 00 08 00 3b 00 01 00 07 00 00 [MM.*.....;......]
  | |     376c: 00 04 30 32 31 30 00 02 00 03 00 00 00 02 00 00 [..0210..........]
  | |     377c: 01 18 00 04 00 02 00 00 00 08 00 00 02 d2 00 05 [................]
  | |     378c: 00 02 00 00 00 0d 00 00 02 da 00 07 00 02 00 00 [................]
  | |     [snip 136388 bytes]
  | | + [AdobeMakN directory, 136468 bytes]

Not parsing:

Code Select Expand

  | 41) DNGAdobeData (SubDirectory) -->
  |     - Tag 0xc634 (38156 bytes, int8u[38156] read as undef[38156]):
  |         4c48: 41 64 6f 62 65 00 4d 61 6b 4e 00 00 94 fe 4d 4d [Adobe.MakN....MM]
  |         4c58: 00 00 03 d8 00 01 01 02 00 00 00 01 00 00 00 01 [................]
  |         4c68: 4e 69 6b 6f 6e 00 02 10 00 00 4d 4d 00 2a 00 00 [Nikon.....MM.*..]
  |         4c78: 00 08 00 37 00 01 00 07 00 00 00 04 30 32 31 30 [...7........0210]
  |         4c88: 00 02 00 03 00 00 00 02 00 00 1c 20 00 04 00 02 [........... ....]
  |         [snip 38076 bytes]
  | + [DNGAdobeData directory, 38156 bytes]
  | | MakN = MM.......Nikon..MM*.7...0210.... .........................................[snip]
  | | - Tag 'MakN' (38142 bytes):
  | |     4c56: 4d 4d 00 00 03 d8 00 01 01 02 00 00 00 01 00 00 [MM..............]
  | |     4c66: 00 01 4e 69 6b 6f 6e 00 02 10 00 00 4d 4d 00 2a [..Nikon.....MM.*]
  | |     4c76: 00 00 00 08 00 37 00 01 00 07 00 00 00 04 30 32 [.....7........02]
  | |     4c86: 31 30 00 02 00 03 00 00 00 02 00 00 1c 20 00 04 [10........... ..]
  | |     4c96: 00 02 00 00 00 08 00 00 02 a2 00 05 00 02 00 00 [................]
  | |     [snip 38062 bytes]
  | | + [AdobeMakN directory, 38142 bytes]
  | | | Warning = Maker notes could not be parsed

It looks like there are some additional bytes in the (prefix) block, but I'm not sure what to make of them. Do you have any clue? I can send you an offending file if you like (>12MB though).

Thanks,
Hyao

[Phil Harvey]

Hi Hayo,

Sure, send me the file and I'll take a look (philharvey66 at gmail.com).

Do you know what version of the DNG Converter produced these files?

- Phil

[Hayo Baan]

File+original sent (it turned out, these were JPG files saved as DNG by Adobe Camera Raw).