Hi Aleksandra,
Thanks for the csv file - it is helpful. I see that the deliminators are semicolons, please convert these to commas. Replying to your numbered items:
1) Looks like the MP4 is likely fine
2) Doesn't like those semicolons
3) OK, I assume this app works and extracts the relevant metadata.
4) The format looks good, but it may not be properly synced with your video frames if you selectively chose the metadata at 1 second intervals. We'll have to see your resulting multiplexed video file.
5) Yes, this is a pain, but you need to specifically format the UNIX timestamp column every time you open excel. It is a case of MS being too helpful.
6) The Phantom is recording RELATIVE height, whereas you need ABSOLUTE height. So determine the true elevation value at your launch site (you can use the Esri Elevation service), then add the Phantom relative height to the actual elevation value. Just add another column to your spreadsheet, enter the true elevation (say 500m) plus the Phantom height for all the cells (500 + 0 for the launch, 500 + 10 for the Phantom relative height of 10m, etc). And add the field heading name of "Sensor True Altitude" to this new column and remove it from your Phantom altitude column, of course.
And so when calculating the 4 corner data in the Video Multiplexer tool, the average elevation to enter is 500 in this example.
Let us know how it works out for you.
Cheers,
Jeff