Hello. I'm an ExifTool and metadata newbie, and I'm trying to understand why there are two Quicktime date tags that have nearly identical names, and how exactly they are different.
exiftool -creat*date -G 20180731T190001.IMG_2776.0.0.MOV
[QuickTime] Create Date : 2018:08:01 00:00:01
[QuickTime] Creation Date : 2018:07:31 19:00:01-05:00
My search online and on this forum has not turned up a clear answer, except that one of them might use UTC and the other reflects the time zone of a device (the camera?). I'm hoping for more background and other details. Can anyone provide? :-)
I also noticed that ExifTool might consider the CreateDate tag more important in some way given that it is returned when using the -alldates shortcut, where the other tag is not. Is it preferred for some reason?
exiftool -alldates -G 20180731T190001.IMG_2776.0.0.MOV
[QuickTime] Create Date : 2018:08:01 00:00:01
[QuickTime] Modify Date : 2018:08:01 00:08:32
The renaming program that was used to add a timestamp to my filename apparently uses non-UTC create/creation metadata, which in this file's case, indicates a different day. This hasn't been a problem (yet), but perhaps I should consider adopting a better standard. Any opinions on that would also be welcome!
CreateDate is part of the movie header. CreationDate is part of the metadata proper. The fact that these differ by the time zone indicates that you should be using the -api QuickTimeUTC option, because they (presumably) should be the same.
The AllDates shortcut is really for EXIF date/time tags, but yes, I would give CreateDate priority although there is the problem of whether or not it is stored properly in UTC as per the QuickTime specification.
- Phil
BTW, you look a lot like Bruce Willis ;)
Thank you. Can you direct me to some (newbie-friendly) documentation on how to use/set the -api QuickTimeUTC option? I assume this is something that is available somewhere on the ExifTool site, but I cannot seem to locate it. :P
P.S. Bruce was one of the available avatars, and since he (coincidently) looks exactly like me, I chose that option.
Here is how to use this option with the first command you mentioned:
exiftool -api QuickTimeUTC -creat*date -G 20180731T190001.IMG_2776.0.0.MOV
- Phil