Hi Phil,
once again I seek help ;)
I have created a csv-import-file with GPS information and the SourceFileTag (gpsout.csv).
The structure is as follows:
"SourceFile","GPSLatitude","GPSLatitudeRef","GPSLongitude","GPSLongitudeRef","GPSAltitude","GPSAltitudeRef","GPSPosition","GPSDateStamp","GPSTimeStamp","GPSDateTime"
"C:/Users/jens/Documents/50_EXIFTOOL/TestGPS/Angkor-050511.dng","13.434870","13.434870","103.891075","103.891075","46.9","46.9","13.434870 103.891075","2019:11:05","01:45:00","2019-11-05T01:45:00"
"C:/Users/jens/Documents/50_EXIFTOOL/TestGPS/angkor-050153.dng","13.434741","13.434741","103.891017","103.891017","36.4","36.4","13.434741 103.891017","2019:11:05","01:48:59","2019-11-05T01:48:59"
I also have a csv-Filelist that includes all the files to be processed
Now if a run
exiftool -csv=gpsout.csv -@filelist.csv
it works perfectly!
But then I changed it, so that the tag are written to an xmp-Sidecar instead of the original image.
Therefore I changed file extensions in both csv-Files to "xmp" and ran the same exiftool command again.
This time it created the xmp-files (yeah!), but only some tags are written. The output for a single file is:
======== ./testgps/Angkor-050660.xmp
GPS Altitude : 16.2 m
GPS Latitude : 13 deg 25' 47.81" N
GPS Longitude : 103 deg 53' 54.65" E
GPS Date/Time : 2019:11:05 09:45:24
GPS Latitude Ref : North
GPS Longitude Ref : East
GPS Position : 13 deg 25' 47.81" N, 103 deg 53' 54.65" E
As you can see, the following tags are missing:
"GPSAltitudeRef","GPSDateStamp","GPSTimeStamp"
I am trying to understand why that happens and if I did something wrong.
Maybe you can enlighten me :)
This is due to the difference between the specification for GPS in EXIF and XMP. There is no GPSAltitudeRef in XMP. Instead, the GPSAltitude value is signed. And GPSDateStamp/GPSTimeStamp are combined into a single tag in XMP.
Also note that GPSPosition is a Composite tag, and isn't actually XMP. Use the -G option to see where the tags are coming from.
It's all a bit confusing, and unfortunate (due to lack of foresight in the original specifications), but hopefully this will makes sense.
There are argfiles in the full distribution (https://github.com/exiftool/exiftool/tree/master/arg_files) for mapping EXIF GPS to XMP and visa versa.
- Phil
I knew there was a logic to it :)
Thank you!