-all= preventing writing new tags

[TSM]

The following has a problem.
When using -all= on MP4 videos all subsequent commands to set metadata do nothing.

Clears metadata but does not set the Copyright field.
exiftool -use WENNMWG -g -j 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4 -use MWG -all=  -Composite:Copyright="Video International"

We are not clearing the metadat, just set the Copyright field which does work
exiftool -use WENNMWG -g -j 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4 -use MWG -Composite:Copyright="Video International"

[TSM]

Ignore me, I am not sure why but its working now, probably a mistake my end.

[TSM]

Nop seems to be a bug, ive added correct paths as they were previously incorrect.
It always shows '1 image files updated' but does nothing in the first instance, works fine with jpg images.
Currently I have to do two calls to get around this, one to clear the metadata and one to then set it without (-all=).

Clears metadata but does not set the Copyright field.
exiftool -use WENNMWG -use MWG -E -all=  -Composite:Description="Video International" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

We are not clearing the metadat, just set the Copyright field which does work
exiftool -use WENNMWG -use MWG -E -Composite:Description="Video International" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

[TSM]

A bit more info on this.

Here is a step by step
1. take source file and run following command which blanks data out but does not apply Description, you can run this as much as you want but still no metadata shows
exiftool -use WENNMWG -use MWG -E -all=  -Composite:Description="Video International" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

2. run the following once and metadata is now written to file
exiftool -use WENNMWG -use MWG -E  -Composite:Description="Video International" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

3. if you then run this it changes the metadata and all is fine
exiftool -use WENNMWG -use MWG -E -all=  -Composite:Description="Video International XXX" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

4. run this and it clears the metadata
exiftool -use WENNMWG -use MWG -E -all= 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

5. we go back and run the same command in step 1, this now does not make any change to the metadata
exiftool -use WENNMWG -use MWG -E -all=  -Composite:Description="Video International" 20160425_MR_Movie_Report_Criminal_No_Music_43a1db8818abda1230e0.mp4

[ryerman]

Make sure you're not trying to write a composite tag.
Composite tags could be described as pseudo tags and are derived from actual, real tags.
http://www.exiftool.org/TagNames/Composite.html

[TSM]

I am using composite tags, but this still does not explain the problems as it works but only if you clear all tags first, this only is happening on these MOV/MP4 files, with JPG its fine and we do a lot of image metadata work on JPG files.

[ryerman]

I'm unfamiliar with using MWG and WENNMWG (whatever that is?) and was surprised to see Composite:anything as a tag name.
But I can reproduce your issue and took the liberty of rephrasing the problem in a new thread:
https://exiftool.org/forum/index.php/topic,7212.0.html

Apparently Phil is on holidays, so it may be a few days before we get an expert's answer.

[StarGeek]

I'm unfamiliar with using MWG and WENNMWG (whatever that is?) and was surprised to see Composite:anything as a tag name.

Apparently, when -use MWG is in effect, Composite:Description is an alias for MWG:Description (today I learned).

I'm still not sure where WENNMWG is coming from since it doesn't appear on anything ExifTool related that I can find on Google.

[Phil Harvey]

There appears to be a bug when deleting all from MP4 then adding back some tags in the same command.  Ryerman started a new thread for this problem, and I'll post there when I have more information.

- Phil

[TSM]

I'm unfamiliar with using MWG and WENNMWG (whatever that is?) and was surprised to see Composite:anything as a tag name.

Apparently, when -use MWG is in effect, Composite:Description is an alias for MWG:Description (today I learned).

I'm still not sure where WENNMWG is coming from since it doesn't appear on anything ExifTool related that I can find on Google.

That is my custom MWG class that overrides the default MWG rules for pulling default data from EXIF/XMP/IPTC sections.
We found that we preferred the data for the Description & Creator fields to be pulled from the IPTC->XMP->EXIF rather than the default (EXIF->IPTC->XMP) where the EXIF field was first as some cameras were putting a description but the metadata editors that some people were using did not modify the EXIF fields and only did the IPTC/XMP fields.
I could have done this in my codebase but did it this way so I would always see what I wanted when testing on the CLI.

[Phil Harvey]

Found the -all= bug.  This should be fixed in ExifTool 10.16 (to be released this week).

Thanks.

- Phil

Edit: Version 10.16 is now available.