ExifTool Forum

ExifTool => Bug Reports / Feature Requests => Topic started by: Zetorg on January 01, 2024, 10:26:49 AM

Title: exiftool -all= does not remove dates
Post by: Zetorg on January 01, 2024, 10:26:49 AM
This command:
exiftool -all= file
Does not remove date-time metadata, which is still available:
Create Date                     : 2010:08:14 00:00:00
Modify Date                     : 2010:08:14 00:00:00
Track Create Date               : 2010:08:14 00:00:00
Track Modify Date               : 2010:08:14 00:00:00
Media Create Date               : 2010:08:14 00:00:00
Media Modify Date               : 2010:08:14 00:00:00

removed with this command:
exiftool -overwrite_original -time:all="" -wm w file
Can't the app just be updated to remove this metadata as well with '-all=' option? Why has to be done separately, is it not EXIF but other kind of metadata like IPTC, XMP, etc.?
Title: Re: exiftool -all= does not remove dates
Post by: StarGeek on January 01, 2024, 11:09:34 AM
The reason is that these tags cannot be removed, only cleared.

Previous post (https://exiftool.org/forum/index.php?topic=10414.msg54897#msg54897) by Phil on the subject.

Quote from: Zetorg on January 01, 2024, 10:26:49 AMis it not EXIF but other kind of metadata like IPTC, XMP, etc.?

It is not EXIF, it is Quicktime metadata (see the Quicktime tags page (https://exiftool.org/TagNames/QuickTime.html)).  EXIF is only a very small percent of the entire range of metadata.  Additionally, EXIF data is non-standard in videos.
Title: Re: exiftool -all= does not remove dates
Post by: Zetorg on January 31, 2024, 06:28:50 AM
Isn't then any flag to remove all metadata that can be removed, and those that can't just clear them?
Title: Re: exiftool -all= does not remove dates
Post by: StarGeek on January 31, 2024, 11:18:39 AM
There is not.

This situation pretty much applies only to videos (and a similar, but different situation with PDFs).  And there can be other data in video files that exiftool can't remove because it is non-standard, such as EXIF data as I mentioned, or embedded in the streams, such as GPS tracks, and exiftool doesn't edit video streams.

The best way to clear video data would be to use ffmpeg with a command like this
ffmpeg -hide_banner -i input.mp4 -c copy -map 0 -map_metadata -1 output.mp4

This will do a lossless remux of the video.  It does not recompress the video and will be as fast as copying the file.  You can also use a program such as AVIDeMux (https://avidemux.sourceforge.net/) to do so.  The settings I use to copy the streams can be found in this post (https://exiftool.org/forum/index.php?topic=11977.msg64673#msg64673).
Title: Re: exiftool -all= does not remove dates
Post by: Zetorg on February 02, 2024, 06:29:49 AM
Thanks a lot, didn't think of that possibility.