Assign Signed value to unsigned GPS altitude

[willm]

Long time listener first time caller...

I am trying to assign a relative altitude value (XMP-drone-dji:RelativeAltitude (real)) to the GPS altitude value (GPS:GPSAltitude(rational64u))

The DJI relative altitude is signed (e.g: +39.6), and the GPS Altitude is unsigned (e.g. 50 m).

When I try to write the relative altitude to gps altitude as below:

exiftool -n -GPS:GPSAltitude=XMP-drone-dji:AbsoluteAltitude dir

I get an error:

Code Select Expand


Warning: Error converting value for GPS:GPSAltitude (ValueConvInv)
Nothing to do.


Is there a protocol to convert signed to unsigned?

[Phil Harvey]

Welcome willm,

The problem is you need to use "<" instead of "=" when copying the value of another tag.  "=" is for assigning a literal value.  This is common mistake 5c.

- Phil

[willm]

Thanks Phil! I knew it would be something silly but could just not figure it out. Working great now, thanks for the fantastic tool!

[julianpatterer]

Thank you very much for the solution, how can I make it add the "+" sign as well?

-exiftool -n -XMP-drone-dji:AbsoluteAltitude<GPS:GPSAltitude -dir

[Phil Harvey]

Like this?:

exiftool -n "-XMP-drone-dji:AbsoluteAltitude<+$GPS:GPSAltitude" DIR

- Phil