tag "not defined" when trying to write but ExifTool reports value when reading!

[camner]

The attached file "exiftool1.jpg" clearly shows, in red, the existence of a tag named "CreationDate" within the "QuickTime" group.  However, the attached file "exiftool2.jpg" shows that when I try to alter the value of that tag with exiftool, Exiftool reports that the tag is not defined and therefore cannot be altered.  Why?  What is going on here, and how can I edit this QuickTime tag?  [Note that this tag is different from the QuickTime "CreateDate" tag, which appears elsewhere in the list]

As a second question, my command was exiftool -all -s -G filename – But, I didn't get "all" the tags!  I only got the tags from the File, QuickTime, and Composite groups.  This file also contains Track 1, Track 2, Track 3, and Track 4 groups, and these were not reported.  What did I do wrong here?

Thank you!

[StarGeek]

The tag can be read, exiftool just can't write it.  Many of the quicktime tags, especially in videos, can be read but not written.

As for the second question, add -a to see duplicate tags, which are suppressed by default.

[camner]

Thanks for your reply. 

For the second question, I tried adding the -a parameter, but that didn't make a difference.  If I understand the -a parameter correctly, that shows duplicate tags, but the issue I am encountering isn't duplicate tags but whole tag groups that are missing (in particular the Track1, Track2, Track3, and Track4 groups).  I know that exiftool can read these tags because (a) ExifToolGUI shows them, and (b) Graphic Converter (Mac), which uses Exiftool as its backend for viewing tags, shows those groups.

[StarGeek]

Ah, my mistake for not reading carefully enough.

Use -G1 and you'll get the track groups.

[camner]

Thanks again.  That did the trick (mostly).  By specifying -G1 I got all the Track1 group tags, but not the Track2, Track3, and Track4 group tags.

I tried specifying both -G1 and -G2 at the same time, but then got some odd output where the group names were replaced by names such as "Video" "Audio" "Time" "Location" etc. 

Using -G1234 (which I didn't really think would work since there is no delimiter) was worse!

So, what would be the right syntax for getting all of the Track n groups?  And what in the world happened when I specified both -G1 and -G2?

[camner]

OK, after poking around the Exiftool FAQ page I tried this:

exiftool -all -s -G1:4 filename

This worked better, but not perfectly.  It reported the tags from Track1, Track2, and Track4 groups, but for some reason skipped Track3.

This is puzzling to me!

[StarGeek]

Keep -a in your command.