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Adjusting GOP settings for camera output


(Etienne Demers) #1

Hello Guys,

I know we can adjust the frame rate on the web interface but I was wondering where I can adjust the GOP settings?

What is the default settings for the camera output?

Thank you,
E.


(Etienne Demers) #2

@jwalser Any idea on this?


(Jacob) #3

All of the adjustable settings are exposed on the camera page. The camera does not provide an interface for this.


(Etienne Demers) #4

Do you know what the basic GOP setting are?


(Jacob) #5

I am not certain. I can look at some diagnostics, though. Is there anything in particular you want to know? May I ask why you need this information?


(Etienne Demers) #6

Hello,

I am programming a video recorder that can record basically anything and generate overlay.

I am able to record IP cameras and now the BR2 camera but I need to know the relation between the key frame and frame rate in order to synch the timecode.

Example: if I am using 25FPS and GOP 50 (1 key frame every 50 frames), I know I am 2 seconds out in my timecode.

This is because I record a stream that I have not started myself and I am recording in native format.


(Jacob) #7

You should be able to determine the type of frame when you decode it and dynamically determine the key frame interval.


(Etienne Demers) #8

Yeah but I just thought you guys might have a quick answer since you set it up…

I don’t always have the ROV besides me to run some tests.


(Jacob) #9

gstreamer has handled this for us, I’ve never had to deal with these parameters.

You can find the keyframe interval using ffprobe, I can try this later on…


(Etienne Demers) #10

Its fine, I use ffprobe also. I thought it would be a quick answer.

Do you guys use ffmpeg to record the video?


(Jacob) #11

We use gstreamer.


(Etienne Demers) #12

lol of course. sorry its 4am over here :slight_smile:


(Jacob) #13

You may be interested in this branch of QGC that has support for text overlay on the recorded video file. The CPU overhead to decode/reencode the video is not practical though, and it will only keep up on high-end hardware.