When I encode an existing MP4 video file orig.mp4 into a new MP4 video file result.mp4 then unfortunately the
GPS location (longitude + latitude) from original MP4 video file is NOT copied by the converter tool (Avidemux).
So I am searching for a workaround to copy the header tags manually.
Is this possible with exiftool?
How should the cmdline command look like for orig.mp4 and result.mp4 ?
The command line depends on where the information is stored. Use this command to determine where it is stored:
exiftool -location:all -G1 -s FILE
Then, if the GPS is in Keys:GPSPosition for example, you would copy it from one file to another for all files in 2 directories like this (assuming the files have the same name)"
exiftool -tagsfromfile ORIGINAL_DIR/%f.%e -keys:gpsposition -ext mp4 ENCODED_DIR
- Phil
You should also note that if there's a GPS track or EXIF data embedded in the file, that cannot be copied. If such data is important to you, then you should keep the original file.
Hmm, when I look into the header fields of the source mp4 video then I found the following GPS values:
keystocopy.png
As you can see
- its in a separate group "UserData" which does not exist in the destination mp4 video any more
- has a different keyname "GPScoordinates" and not "gpsposition"
- it is unclear if this is a "embedded" value "which cannot be copied" or not
I tried the following:
exiftool.exe -tagsfromfile src.mp4 -keys:GPScoordinates dest.mp4
and got the following output from exiftool:
Warning: No writable tags set from D:\todo\test\src.mp4
0 image files updated
1 image files unchanged
So whats wrong?
An additional problem is that a src exif header value should not only be copied into an existing header field in dest. Instead the header field GPScoordinates must be created at first and that under a (new) group "UserData". How can I achieve this?
It is UserData:GPSCoordinates, not Keys.
- Phil
Quote from: pstein on June 07, 2024, 12:19:49 AM- its in a separate group "UserData" which does not exist in the destination mp4 video any more
The
UserData group will be created when you copy the data.
Quote- has a different keyname "GPScoordinates" and not "gpsposition"
That was a typo in Phil's post.
GPSCoordinates is the embedded tag and can appear in the
Keys,
ItemList, and
UserData tags (which are all sub-groups of Quicktime tags (https://exiftool.org/TagNames/QuickTime.html)). This is the madness of video metadata, where the same tag can appear in multiple locations.
GPSPosition is a Composite tags (https://exiftool.org/TagNames/Composite.html) which will write to the
GPSLatitude/
GPSLongitude tags at the same time.
QuoteAn additional problem is that a src exif header value
Minor nitpick, this is Quicktime data, not EXIF data. All EXIF data is metadata, but not all metadata is EXIF data.
Quote from: StarGeek on June 07, 2024, 11:14:13 AMThat was a typo in Phil's post.
(or Phil's bad memory. :P)- Phil
Quote from: Phil Harvey on June 07, 2024, 07:48:36 AMIt is UserData:GPSCoordinates, not Keys.
works :)
Thank you
One more related question:
Assume I want to copy ALL header fields whose keynames contain the pattern *CreateDate (in several different groups) at once. Is this possible with wildcards?
In detail I want to copy all timestamps (if they exist in source video) from
Track1:TrackCreateDate
Track1:MediaCreateDate
Track2:TrackCreateDate
Track2:MediaCreateDate
QuickTime:CreateDate
-*.*CreateDate
does not work.
Similarly: How can I copy ALL header fields in group "UserData"?
simply use -UserData or -UserData: instead of -UserData:GPSCoordinates does not work
Close. You need a colon instead of a period after the group name: "-*:*CreateDate" or "-all:*CreateDate"
And "-userdata:*" or -userdata:all will copy all of the UserData tags.
I suggest you read and try to understand the -tagsFromFile documentation (https://exiftool.org/exiftool_pod.html#tagsFromFile-SRCFILE-or-FMT) as this is a powerful feature with vast possibilities.
- Phil
Everything works fine. Great!
However one minor problem remains:
In source video file a group "Samsung" exists with a key inside:
SamsungModel = SM-A528B
Similar to copying the whole UserData group I want to copy "Samsung" group too with the following parameter:
-"Samsung:all"
but it is not copied.
Again: -"UserData:all" works (even in the same command).
So I could imagine that exiftool copiess only pre-defined, well known groups but not unknown one.
Is this the reason?
The Samsung group are MakerNotes, which are a subset of the EXIF group. As I said above, EXIF data cannot be copied into another video. The reason for this is that there isn't a standard for doing so and every camera company does it in different ways.
If you look at the Samsung smta Tags documentation (https://exiftool.org/TagNames/Samsung.html#smta), you will see that SamsungModel is not writable.
The good news is that basically nothing but ExifTool and maybe some Samsung software will read this.
- Phil
Ooops, me jumping to conclusions again.