GoPro creation metadata on Google Photos different for photos and videos (timezone offset?)

Question

If I take a video and a photo at the same time (both also have GPS tags in metadata, BTW) and upload them on Google Photos, the video will be wrongly sorted in the album because its creation time is thought to be +2 hours GMT. in Mediainfo.exe the creation date is correct (in UTC) and same as in the EXIF of the photo.

If I convert it with ffmpeg with -map_metadata 0 the problem persists.

Does it makes sense to raise a bug for Google Photos or GoPro or it's something I am doing wrong? (I did a whole lot of research but did not find anyone struggling to find a fix for exactly this issue)

Is there a ffmpeg parameter to shift the creation_time back 2 hours so my album is aligned?

something like this bat file would suffice

c:\gopro\ffmpeg" -i %1 -vcodec copy -acodec copy -metadata creation_time="+02:00:00" "%~n1.remux.mp4

i also found about mp4box but did not find such option in command line / bat file

my research that did not help 1 2 3 4

Answer 1

Assuming that the timestamp shows the exact same value for both the images and video, then that is the source of the problem. Video timestamps in MP4/Mov files is supposed to be set to UTC. Image files, on the other hand, are assumed to have the time set to the local time where the image was taken.

Google Photos (as well as Windows and Mac) understand that the timestamp for video files is in UTC and will adjust it to the local time when displayed. Side note, Adobe programs such as Photoshop/Lightroom, do not properly adjust the time in video files.

For MP4/Mov files, Exiftool would be better for adjusting the timestamp, as it will not remove any GoPro specific metadata, such as any GPS tracks. You could use a command like this to subtract two hours from the video's main timestamps
exiftool -CreateDate-=2 -ModifyDate-=2 /path/to/files/

There might be other timestamps in the file, such as stream specific timestamps. If you wish to adjust all the timestamps, you could use
exiftool -Time:All-=2 /path/to/files/

This command creates backup files. Add -overwrite_original to suppress the creation of backup files. Add -r to recurse into subdirectories.