Canon:OwnerName not writeable

[axel.hennig]

Hi,

I tried to write the Canon-OwnerName to an *.mp4 file (can be downloaded here) from a Canon EOS 80D but wasn't successfull.

I've used the following command (on Windows):

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exiftool.exe -overwrite_original -OwnerName=test vid.mp4
And the result when running

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exiftool.exe -G1 -OwnerName -a -s vid.mp4>out.txtis just:

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[Canon]         OwnerName                       :
[ExifIFD]       OwnerName                       :
[XMP-exifEX]    OwnerName                       : test

I think the documentation says that Canon-OwnerName is writeable but even if I try

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exiftool.exe -overwrite_original -Canon:OwnerName=test vid.mp4it is not working.

Can anybody help here?

[Phil Harvey]

The OwnerName is actually stored in the embedded ThumbnailImage in Canon MP4 videos.  ExifTool automatically extracts metadata from this thumbnail when reading, but doesn't automatically edit the thumbnail when writing.  I don't like asymmetries like this, but editing the thumbnail is very unusual and it could be confusing if ExifTool did this automatically.

Since it isn't automatic, you must do it manually.  This may be done with a command similar to the last one in the PIPING EXAMPLES:

exiftool test.mp4 -thumbnailimage -b | exiftool -ownername=test - | exiftool test.mp4 -thumbnailimage"<=-"

I'm not sure if this piping will work in Windows, so here it is as 3 separate commands:

1. exiftool test.mp4 -thumbnailimage -b > thumb.jpg

2. exiftool thumb.jpg -ownername=test

3. exiftool test.mp4 "-thumbnailimage<=thumb.jpg"

- Phil

[StarGeek]

I'm not sure if this piping will work in Windows, so here it is as 3 separate commands:

I haven't tested it but it should work using Windows CMD.  PowerShell will corrupt binary data passed through pipes/redirection.

[axel.hennig]

Thanks Phil, really great support.

Your answer is

• interesting
• working

[axel.hennig]

ExifTool automatically extracts metadata from this thumbnail when reading, but doesn't automatically edit the thumbnail when writing. I don't like asymmetries like this, but editing the thumbnail is very unusual and it could be confusing if ExifTool did this automatically.

Would it make sense to add an option to do this automatically (syncing metadata and metadata in thumbnail)? In that case the user could decide if he wants that or not.

[Phil Harvey]

It probably would, but it would also be a lot of work because each manufacturer has their own way to store EXIF metadata in videos, and I don't think there is enough demand to warrant the effort.

- Phil