Video Meta Data: DJI Drones

Published: 2024-06-16
Last Updated: 2024-06-18 18:24:28 UTC
by Johannes Ullrich (Version: 1)
1 comment(s)

Many years ago, I wrote about the EXIF data in pictures taken with Smartphones. Smartphones often record extensive meta data, including GPS and accelerometer data.

So I wondered how much similar data can be found in footage collected with a drone. As an example, I am using a DJI Mini Pro 4 drone. This is a very common and popular drone, and I have footage available.

The drone has the ability to record video as well as still photos. For the still photos, typically saved in JPG format, the data looks like what you expect from a smartphone. It includes camera parameters, date, time, and GPS coordinates (oddly, the height was VERY wrong in my sample if I used the "exists" tools, but inspecting it with a homemade tool, it looks better. Likely just an encoding issue)

Here is the complete EXIF data from a sample image

Tag Value
exiftags invalid field offset (Make)
exiftags maker note not supported
Camera-Specific Properties  
Camera Model FC8482
Camera Software
Maximum Lens Aperture f/1.7
Focal Length (35mm Equiv) 24 mm
Image-Specific Properties  
Image Orientation Top, Left-Hand
Horizontal Resolution 72 dpi
Vertical Resolution 72 dpi
Image Created 2024:03:20 11:43:03
Exposure Time 1/2500 sec
F-Number f/1.7
Exposure Program Normal Program
ISO Speed Rating 100
Lens Aperture f/1.7
Exposure Bias 0 EV
Subject Distance 0.00 m
Metering Mode Average
Light Source Daylight
Flash No Flash
Focal Length 6.72 mm
Color Space Information sRGB
Image Width 4032
Image Height 2268
Rendering Normal
Exposure Mode Auto
White Balance Auto
Scene Capture Type Standard
Gain Control None
Contrast Normal
Saturation Normal
Sharpness Normal
Latitude N [redacted]
Longitude W [redcated]
Altitude 4294927.26 m 
GPS Status Measurement In Progress
Geodetic Survey Data WGS-84

The coordinates are the coordinates of the drone, not the coordinates of the operator. The serial number of the drone is not displayed. Note that the serial number uses an "Unknown" exif tag and is only displayed with the -u option in exiftags

"Unknown Tags"

Attribute Value
Title default
GPS Info IFD Pointer 746
Unknown 972
Unknown 1100
Unknown 2
Manufacturer Notes 890
Supported FlashPix Version 808464688
Interoperability IFD Pointer 860
Device Settings 0
Unknown 6TVQL[redacted serial number]
Unknown 24
Unknown DJI FC8482
Unknown R98
Unknown 808464688

Some of the "Unknown" data may be sensitive, but I have not redacted it so far. Let me know if I should :)

The video data is a bit more complex. DJI saves 3 different files:

  • MP4 File: This is the main, full resolution video file
  • LRF File: Lower resolution video file
  • SRT File: A file with GPS coordinates in "Subtitle" format (more below)

Users sharing a file are most likely going to share the MP4 file. Like the JPEG, some metadata is embedded in the MP4 data stream. It is less verbose than the JPEG data, but it does include the drone's serial number. I did not find GPS data in the MP4 metadata. Just information about the camera and firmware.

hex dump of mp4 file

The SRT file contains some basic GPS data for each "time slice". In this format, it can easily be overlayed to the video file.

00:00:00,033 --> 00:00:00,066
<font size="28">FrameCnt: 2, DiffTime: 33ms
2024-03-20 12:59:17.852
[iso: 400] [shutter: 1/320.0] [fnum: 1.7] [ev: 2.0] [color_md: default] [focal_len: 36.30] [latitude: 30.xxxxxx] [longitude: -81.xxxxxx] [rel_alt: 6.500 abs_\
alt: -32.309] [ct: 5695] </font>

Again, only the drone's GPS data is saved, not the operator's location. It has been well documented that DJI includes the operator (or better controller) location in the datastream sent to the drone, in part to comply with regulations in some locales [1]. An image file doesn't necessarily give it away.




Johannes B. Ullrich, Ph.D. , Dean of Research,

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