Write Starting GPS Location tags to MP4 automatically

[thisisbommy]

As discussed elsewhere, it would be cool if this tool could be set to...

• Write the full GPS data to a GPX (existing behaviour)
• Write the first GPS location point in the file to the MP4, as readable data for Immich, Mac Photos and other such apps
• Or both together

I've been playing with a dedicated script to do this once I have the GPX, and also with SRTs from DJI Drone MP4s.

The script writes two metadata fields into the processed MP4 using ExifTool:
1. Keys:GPSCoordinates
• Value contains latitude + longitude, and absolute altitude if present in the SRT.

3. 2.	Keys:LocationAccuracyHorizontal
•	Set to a constant of 10

Then in ExifTool I'm using
• -overwrite_original (writes into the MP4 in-place)
• -api LargeFileSupport=1

So far it seems to work.

[francescocaponio]

As I wrote in #2, it's really a nice idea to implement this feature. Let me start looking for how to implement such a feature.

I would not do it automatically while extracting the gpx, but as a different command, to prevent accidental file overwriting.

Do you have a working python code to do the work done with ExifTool? It would be nice a pythonic implementation to prevent calling an external process. Even the MP4 is now parsed for metadata in python rather than relying on external tools (even if it was faster by calling ffmpeg, but maybe less easy to use in different environments).

[thisisbommy]

OK, understood.

No, my script (which I'm happy to share) relies on ExifTool.

[francescocaponio]

So, I did some tests on a separated python script and it seems possible to replicate a metadata box inside the mp4 which stores GPS coordinates, altitude, and the camera model used to shoot the video, together with the creation datetime. I tested it by uploading the generated video on immich and it was added in the library according to the metadata creation datetime, while also recognizing the location.

I still need to integrate this portion of code in the lib and add the command to copy the video while adding the metadata.

Will you be willing to test it from the PR branch in the next days?

[thisisbommy]

Yep, I'll give it a go over the weekend!

[francescocaponio]

I pushed the code in the PR #6.
I used one of your videos to do a test, and this is how it appears in immich after processing it:

It is just a first test, it may be still hide bugs, but if you have additional videos, can you do a test?