Creating a Video with GPS Data as Subtitles

We want to overlay GPS data (speed, altitude, time, and coordinates) on a video, synchronized with both time and movement. One situation where I’d need this is when I have a sports or dash camera that doesn’t have GPS. Besides the camera, we also need a smartphone that can record GPS data along the route we’re filming, and the app we use must be able to export GPX files.

First we start the app on the smartphone, then the video recording. At the end, we stop the video first, then the route recording. This way we’ll have GPS data recorded for the entire duration of the video clip.

A GPX file looks like this:

We can see that the recording started at 18:26:00 (line 17), but the first logged point appears at 15:26:00 (line 19). That’s because the start time is taken from the phone (Eastern European Time in my case), while the logged time is taken from the GPS satellite, which uses GMT. We need to remember to add 3 hours for correction (if daylight saving time is in effect) or 2 hours (if standard time is in effect).

Since the first line is useless to me (from the video file name I know the recording started at 18:26:13), we’ll delete line 19 or any other lines that contain GPS data recorded before the video started.

To convert GPX to SRT we need the GPSBabel app (free).

Under Filters we choose

Move – 3 hours (the correction I mentioned above) and we tick Speed, so it will also calculate the speed for us.

Under Options we choose the subtitle format. Clear explanations are in Help.

Here I can also use the first 3 parameters if I want second-level accuracy. Explanations are also in Help.

Now I have all the parameters I need, I can start the conversion.

The result looks like this:

1
00:00:00,000 --> 00:00:13,000
0.0 km/h 85 m
18:26:23 Lat=45.72882 Lon=21.23525

2
00:00:13,000 --> 00:00:26,000
4.6 km/h 90 m
18:26:36 Lat=45.72882 Lon=21.23503

.....
.....

Basically, for each GPS record a subtitle with two lines is created.

Now you can upload the subtitle file in YouTube Studio

And the result…

Sources: Photo by Vecteezy

Innoxius

Programming, graphic design, and cooking relax me. The fact that I also earn some money from the first two is just a minor detail. I’m skilled in Microsoft Office and LibreOffice (including developing applications for Office), all sorts of IT&C tools that make life easier, web design (Joomla and WordPress, with a bit of CSS and PHP), SEO optimization, and Google Ads campaigns. I like traveling — to non-Instagrammable places. I use a Motorola Edge 50 Ultra, which doubles as my laptop (together with a 15″ Viewsonic touch display and a Logitech K380 keyboard + Logitech M720 Triathlon mouse). PS: I have a 2007 Logan. I keep it just to joke about it, to embarrass it.