Ask a Question
GoPro Support Hub Ask a question. Share an answer. Find a solution. Stay stoked.
Announcements
Is your GoPro gear up to date? Check to see If it is on our Update page.
Reply
This is an open group. Sign in and click the "Join Group" button to become a group member and start posting.
Sightseer
Posts: 2
Telemetry Camera Orientation Definitions

I am using goprotelemetryextractor.com to extract telemetry data, but I can find no defintions. I appologize if this is a dumb question, I have tried searching.

 

Ultimately I want to know the orientation of the camera relative to the velocity vector.

 

The "Camera oriention" has four fields, labeled "CameraOrientation" , "1", "2", "3". If I rotate the camera with me stationairy, through pitch, roll and yaw, I can see 1,2, and 3 going from -1 to 1, which make sense. ...but what are the units?

 

I thought I needed multiply by 180 to get them in units of degrees. But when I went driving in a car, it showed pitch changing from -30 to 60 degrees, where it should have been in the single digits.

 

I then though the 1,2,3 was a unit direction vector, but the Norm of the 1,2,3 vector does not equal unity. Are they relative to the gravity vector?

 

Thanks in advance for any help,

Tim (GoPro Rookie)

Nomad
Posts: 1,109
Re: Telemetry Camera Orientation Definitions

Hi there,

The reason there are no definitions is the camera can potentially record any type of data, and is also able to label the data so that it is self-explanatory, but that's not the case with the orientation streams, generally. The components are just labelled "CameraOrientation" , "1", "2" and "3" precisely because the camera does not label them, so the extractor just gives them numbers so they can be identified.

According to GoPro ( https://github.com/gopro/gpmf-parser#hero8-black-v12-adds-removes-changes-otherwise-supports-all-her... ) that stream is expressed in quaternions. I personally find them very complicated, so here's some background on what they are: https://youtu.be/d4EgbgTm0Bg

Finding out the orientation of the camera relative to the velocity involves some challenges. You could also use a combination of the gyroscope and the accelerometer sensors. Anyway, it will be interesting to see your progress, so feel free to post updates here.

How to think about this 4d number system in our 3d space.Part 2: https://youtu.be/zjMuIxRvygQInteractive version of these visuals: http://3imaginary1real.com...
Sightseer
Posts: 2
Re: Telemetry Camera Orientation Definitions

Ohhhhh Quanternians----I shoulda thought of that. My first clue should have been 4 values instead of 3. Thanks !!!

 

I love that video. 

 

Yes, I plan on playing with all the telemetry (gyro, accels, etc). Camera oreientation is the one that I found the most interesting... so I started with that one.

 

Thanks so much for your help.

 

Tim

Hiker
Posts: 16
Re: Telemetry Camera Orientation Definitions

Hi,

GoPro 9 vibration animation was created using extracted metadata. The below video was uploaded in Japanese, but you can easily understand what I intend to do. I used Matlab to make an animation. When making it, Camara orientation quaternion is not appropriate because of the integral error of angle velocity. Instead of that, I used image orientation quaternion. Image orientation quaternion has miller rotation, so the sign of three complex numbers, i, j ,k must be inverted. See

https://studio.youtube.com/video/SJDejDp7MPA/edit

Hiker
Posts: 16
Re: Telemetry Camera Orientation Definitions
GoPro 9用、52mmフィルターアダプター:https://www.amazon.co.jp/gp/product/B08R3MBBMR/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1CPLフィルター:https://www.amazon.co.jp/gp/p...
Nomad
Posts: 1,109
Re: Telemetry Camera Orientation Definitions

Interesting. Thanks for sharing this!