Makernotes Sanyo

[Archive]

[Originally posted by geve on 2006-11-11 00:00:59-08]

Some Sanyo camera's have (I assume) a software fault. For example the C4, J2 and J4 calculted the offset pointer for makernotes 12 to high

For example your picture sanyo-C4.jpg results in
sanyo-C4.html and should look like sanyo-C4.rmaker

p.e. Exif tool tag "MakerNotes_05 DigitalZoom" points to h'05cc and is located at h'05c0, see rmaker file "Makernote field-6".

Q1: should Exiftool handle software faults?

Q2: and rewriting the data should it repair, or make the same mistakes?

Ger

[Archive]

[Originally posted by exiftool on 2006-11-11 03:11:00-08]

Hi Ger,

Thanks for pointing out this problem.  My philosophy is that ExifTool
should handle problems like this and duplicate them when rewriting
the image.  (Believe me, there are far worse things that makers do
with their offsets than this!)  I will take a look at my Sanyo samples
and see if I can come up with a general way to fix this.  If not, I will
resort to recognizing individual models if necessary.  Give me a few
days to think about it.

- Phil

[Archive]

[Originally posted by exiftool on 2006-11-13 15:43:39-08]

I have looked into this.  The current version of ExifTool will read and write
these maker notes properly if you use the -F option.  I will add a patch to
fix the maker notes offsets automatically for this camera model and the update
will appear in ExifTool 6.56 when it is released.  Normally a warning would
be issued when ExifTool detects a possible problem with the maker notes
offsets (as a clue that you should try -F), but some other manufacturers
leave 12 bytes of unused data at the end of the IFD, which looks exactly
like a 12-byte offset error, so the warning message was being suppressed
for this case.

So if you use the -F option (and without the -F option with ExifTool 6.56
or greater), the error in the offsets will be preserved when the file is rewritten.
This is in keeping with my philosophy of trying to preserve the original
structure of the image.

- Phil