Print Page - (some) tags of the Canon group cannot be written

Title: (some) tags of the Canon group cannot be written
Post by: spitfire_ch on March 31, 2019, 06:21:59 PM

First of all, thanks very much for creating ExifTool and your continuous support!

When trying to write Tags from the CanonGroup, I run into a problem for many tags of this group. Without any specific error message, I get the following feedback:

exiftool -Canon:FocalLength="6.1 mm" f:\TestMovies\CameraTest\CanonG12\MVI_4929c.MOV
0 image files updated
1 image files unchanged

Nothing is being written. If I skip the group and just use -FocalLength="6.1 mm", the tag is written but the XMP-exif group.

Is my suspicion correct, that the tags in the Canon group cannot be written? If so, maybe the Canon Tags section (https://www.exiftool.org/TagNames/Canon.html) should be adjusted. At least MaxFocalLength and MinFocalLength are listed as writeable int16u.

Thanks very much for looking into this and best regards
Pesche

P.S. I was using a Canon Powershot G12, converted the movie using FFMPEG and tried to apply the tags from the original to the converted movie (or just set a tag in the converted movie).

Title: Re: (some) tags of the Canon group cannot be written
Post by: Phil Harvey on March 31, 2019, 09:09:36 PM

Makernote tags are not yet writable in MOV videos (currently just JPEG, TIFF, RAW, etc). From the current QuickTime tags documentation (https://exiftool.org/TagNames/QuickTime.html):

ExifTool currently has a limited ability to write metadata in QuickTime-format videos. It can edit/create/delete any XMP tags, but may only be used to edit existing tags in native QuickTime metadata.

I'm working on expanding this.

- Phil

Title: Re: (some) tags of the Canon group cannot be written
Post by: spitfire_ch on April 01, 2019, 02:37:07 PM

Thanks for the explanation! I'll try to change the output format, then. Would mp4 or mkv work?

Best regards
Pesche

EDIT: I just tried that.
MKV returns the info of not being supported: "Error: Writing of MKV files is not yet supported"
MP4 behaves like MOV: it does not return an error, but does not write the tags, either:
0 image files updated
1 image files unchanged

EDIT2: Only now your list of supported file types popped into my eyes. I apologize for the unnecessary questions!
Maybe you could add another column for "maker notes" after EXIF, IPTC, XMP, ICC, though.

Title: Re: (some) tags of the Canon group cannot be written
Post by: Phil Harvey on April 01, 2019, 09:23:35 PM

The maker notes generally come under the heading "EXIF", since most maker notes are EXIF format.

- Phil

Title: Re: (some) tags of the Canon group cannot be written
Post by: spitfire_ch on April 02, 2019, 02:52:20 PM

I see, thanks for the info!

ExifTool Forum

ExifTool => Bug Reports / Feature Requests => Topic started by: spitfire_ch on March 31, 2019, 06:21:59 PM