Hidden information in recorded video on Air2s (and maybe others)

[Firejay27]

This may be new to some and for others you may say .. yeah I knew all about that. Anyway, I have two Synology NAS units that I use to backup my photos and video and I thought just for grins I would try using the Synology video station. When I started playing back my videos though there was all this data on the bottom of the screen and I thought I had turned on some feature of the drone that I didn't realize existed and ruined my footage. Come to find out DJI is capturing a lot of information when you record video and stuffing it into the subtitle track data. I'm finding this to be super helpful information as it contains things like shutter speed, focal length, iso, altitude and some other items. Great for when you go back and want to know what settings you had used on a video or how high you were flying when you got that perfect shot. I attached an example of the information here as well as what it looks like in the Synology Video app. Not sure if you can overlay the same information by using the subtitles information in Adobe or DaVinci but it's there.

 

[Yaros]

Yep, that's the subtitles. It works by providing an SRT file in the same folder as your MP4/MOV files, with the same name.
It is pretty cool, but I never tried to import it into Davinci Resolve, although I think it is possible, for my purpose, drone videos, I don't really need it.
I actually even have it disabled in the drone's settings, from the Camera Settings you can turn this on and off.

 

[Yorkshire_Pud]

@Firejay27
You may indeed have, in the App, switched on the recording of "subtitles" when shooting video.
I am pretty certain I have see the option in the Fly app but can't remember in which section of the control menus it was. I don't have a phone/drone to hand to check.

In addition it is quite likely that you can switch displaying/replaying subtitles OFF in the video player that you are using and that the video would then play without displaying that telemetry.

 

[retiredNH]

Confirming the above:
- DJI fly has a setting to turn subtitles on or off.
- Many, but not all, video players give you the option of showing subtitles (if the .srt file is in the same directory).
- This data is usually called "telemetry data"
- Dronviewer Plus, Telementary Overlay (and others?) handle the subtitle info in creative ways. Divinci Resolve, to my knowledge, does not.
Edit:
Resolve can handle subtitle files, but the results are not pretty. If you want to use the data, one of the dedicated tools is the way to go, like the ones I mentioned.

 

[spamgnome]

@Firejay27

In addition it is quite likely that you can switch displaying/replaying subtitles OFF in the video player that you are using and that the video would then play without displaying that telemetry.

absolutely.

 

[spamgnome]

Is that Lakewood Park in Leander? Just a few miles from my house.

 

[MavicAir2Marc]

There are also some programs that can convert the SRT files into a cool looking telemetry display on your video that simulates the info you get on your screen while flying.

 

[retiredNH]

There are also some programs that can convert the SRT files into a cool looking telemetry display on your video that simulates the info you get on your screen while flying.

Already mentioned a few, but note that they don't "convert" the .srt file data. They use it to display the information in useful ways. Big difference.

 

[Zbip57]

Yep, that's the subtitles. It works by providing an SRT file in the same folder as your MP4/MOV files, with the same name.

DJI's generated SRT file is recorded in plain ASCII text and can be edited using any text editor.

Sample:

1
00:00:01,000 --> 00:00:02,000
HOME(-xx.9233,xx.0141) 2022.08.16 12:02:26
GPS(-xx.9233,xx.0141,16) BAROMETER:0.0
ISO:100 Shutter:3200 EV:-2/3 Fnum:F2.8

2 [...]

The DJI app records a one-second duration entry for each second, with the text as shown above. But you can manually edit/delete/add as much text as you want, or adjust the timestamps as needed down to millisecond accuracy.

If you upload the SRT file with your video to YouTube, it will display the SRT file as closed-captioning text whenever the CC button is enabled. It is good to include such a text transcript if your videos include any talking, as hearing-impaired viewers won't otherwise know what you're saying.

YouTube Studio includes a very handy feature for editing CC content, or even auto-generating it (which usually requires cleaning up).

I made a short video (non-drone-related) of my mom's fat little dog splashing around in the swampy section of our lake's shoreline, with commentary to resemble the old National Film Board - Hinterland Who's Who series of TV commercials. Some friends, who are hearing impaired, complained they couldn't understand what I was saying. So I added the CC text, and learned how easy it to use YouTube's editor for that.

Click the CC button on the YouTube screen bottom right toolbar to enable the closed-caption SRT file.

 

[Jurgen]

Telemetry overlay is an awesome tool not just for drone footage, but action cams, phone footage, really anything that has a GPS track.

Telemetry Overlay & Extractor for GoPro, DJI, Insta360 & more

Extract, interpret, visualize and convert telemetry from GoPro, DJI, Insta360 & more videos. Create amazing data visualizations, gauges and dashboards with professional workflows

goprotelemetryextractor.com

 

[Firejay27]

Is that Lakewood Park in Leander? Just a few miles from my house.

Yes it is. I'm out there a fair amount trying different things. Either I'm in the dog park with my dog or flying.. sometimes both.

 

[Firejay27]

Thanks for all the replies. I always wondered what the setting was for turning on subtitles in the app since there's no microphone and stuff. I'm finding the information useful for testing different exposures and such when shooting. Dont necessarily have to carry a notebook now.