Warning: [minor] Maker notes could not be parsed - Canon PowerShot G1X Mark III

[ChrisCam]

Hi,

if I use

exiftool -P -DateTimeOriginal+=1:30 -CreateDate+=1:30 -ModifyDate+=1:30 -FileModifyDate+=1:30 \imagefolder

all the dates change as they should. However, I got two warnings:
Warning: [minor] Missing 2 entries in CanonCustom2 group 4 directory - IMG_0090.CR2
Warning: [minor] Maker notes could not be parsed - IMG_0090.JPG

The first one seems not to be so important at this moment, because the original image-file shows the same warning as I already described here and hope will be fixed:
https://exiftool.org/forum/index.php?topic=11998.0

The second warning instead is not only a warning but all the information of Canon get erased/will not show up if I open the image, e.g. in ACDSee.

How can I avoid this behavior?

If I only use

exiftool -P -FileModifyDate+=1:30 \imagefolder

there are none of the two warnings but the important dates will not be changed 

[StarGeek]

Just to verify, you did not change the Make or Model tags of the file?  If so, see FAQ #8.

Otherwise, it sounds as if the MakerNotes got corrupted.

[ChrisCam]

No, the files are fresh from the camera without changing anything at the file.
The MakerNotes appear nicely in ACDSee when I just open the fresh copied files from the Camera.

Just after I try to use either of -DateTimeOriginal+=1:30 or -CreateDate+=1:30 or -ModifyDate+=1:30 the Canon-information will be lost. That doesn't happen if use -FileModifyDate+=1:30 only.

[StarGeek]

Can you make a sample available?  Phil might want to look at it if exiftool is damaging an image straight from the camera.

That doesn't happen if use -FileModifyDate+=1:30 only.

That's because that's part of the underlying file system, not an embedded tag in the image.

[ChrisCam]

Thanks for the info.
Here's a sample I just took a minute ago and transfered the file via USB connected directly to the camera.

[Phil Harvey]

This is a deficiency in ACDSee.  The makernotes are not rebuilt when ExifTool writes this file due to the Canon firmware bug which writes an incorrect count for the makernotes IFD (it stores a count of 48, but in fact there are 47 entries).  But the offset information is included so they are fully decodable even though the location changes when you modify the file.  ExifTool can extract all the makernote information with no problem, but you will get 1 more warning with the edited file:

Code Select Expand

> exiftool -validate -warning -a IMG_2891.JPG
Validate                        : 3 Warnings (2 minor)
Warning                         : [minor] Missing 2 entries in CanonCustom2 group 4 directory
Warning                         : Possibly corrupted CanonCustom2 data
Warning                         : [minor] Bad format (0) for MakerNotes entry 47
> exiftool -DateTimeOriginal+=1:30 IMG_2891.JPG
Warning: [minor] Maker notes could not be parsed - IMG_2891.JPG
    1 image files updated
> exiftool -validate -warning -a IMG_2891.JPG
Validate                        : 4 Warnings (3 minor)
Warning                         : [minor] Adjusted MakerNotes base by -76
Warning                         : [minor] Missing 2 entries in CanonCustom2 group 4 directory
Warning                         : Possibly corrupted CanonCustom2 data
Warning                         : [minor] Bad format (0) for MakerNotes entry 47

- Phil