OpenROV 2.8 poor frame rate?


#1

Hello! Awhile back I build my own ROV, and sadly it’s no longer in service. I want back in the game, and I’m very interested in OpenROV 2.8, but all the videos I’ve found on YouTube of OpenROV streams appear to have very poor frame rates (<15 fps). Even if you use a good computer, is this typical? Is 1080/30fps or 720/30fps possible without modification? If so, can someone provide a link to a video showing it’s full capabilities? Thank you.

Here’s a video of my old ROV in case anyone is interested: Homemade ROV exploring UCF’s Lake Claire. The analog camera had great low-light performance, and 30fps, but the resolution was obviously poor (recording was done with a gopro).


#2

No one? :frowning:

I’m probably going to go with the HD camera upgrade. At $350, it’s pricey, but the quality looks fantastic for live feed.


#3

I can’t comment on the OpenROV 2.8 as I don’t have one, however I have done some research into cameras and have my own homemade ROV. What I have found is the frame rate and latency are highly dependent on the video encoding and streaming implementation. I use a Logitech C920, which has inbuilt H264 encoding and stream using Gstreamer through a Raspberry Pi to my laptop. I easily get 720/25fps with very low latency and can even do 1080, although my laptop screen resolution isn’t high enough.

I cannot recall what the OpenROV 2.8 uses but I am pretty sure it does not have inbuilt H264 encoding, thus requiring the beaglebone to do some processing.

I would imagine the new HD camera being offered has some solution to provide high speed encoding as well as superior low light sensitivity. This is one area where off the shelf webcams are not the best.


#4

@william_alexander is correct in his assessment of the cameras that we are using.

The stock camera on the v2.8 is a Genius F100 web-camera and is processed on the BeagleBone Black into an MJPEG stream. This causes increased latency and the decreased frame rate.

The new HD camera we have been designing to be fantastic for capturing underwater video. The camera encodes into an H.264 stream which decreases the latency and reduces the CPU load on the BeagleBone Black. The camera has a high dynamic range to handle high contrast situations and works much better in low light situations. The lens and focus is also set to match the sensor and the underwater environment. We have spent a lot of time on the design of this camera (for Trident as well as for the 2-series) because we know this is the most important sensor on the vehicle.

Having flown with both cameras I find the new one much better. While the image quality is better the biggest difference is in the latency. We have been working to reduce it as much as possible and makes the vehicle much more responsive because when you give a control command you get very fast visual feedback of the change in direction. This makes for a very different flying experience. The greater resolution and frame rate are also extremely nice to have :slight_smile:


#5

@tgfeminella,
Make sure that you carefully build the End Caps according to the Assembly Manual and vacuum test thoroughly or that $350 HD camera is going to be an expensive loss if you suffer water intrusion!
Regards,
TCIII AVD


#6

I’ll most likely start with the stock camera setup until I have the ROV working well, then upgrade. Thank you.