[Snippet] Using 2+ Cameras with minimal bandwidth usage

[Justin Buist]

Originally Posted by fovea1959

kmodos: thank you very much. works perfectly for us.

has anyone figured out how to open both cameras at once? we would like to open both camera, grab a frame from each, lay them down side by side in a double size frame, and send *that* to the DS. The problem is that IMAQdxConfigureGrab throws an exception if you already have called it with*out* an intervening MAQdxStopAcquisition.

It's possible, but you'd have to roll your own version of CameraServer. It's not terribly hard. I put one together last week so we can publish OpenCV Mat images back to the dashboard. The protocol for getting stuff back to the dashboard is pretty simple. Just take a peek at the GRIP code for doing it (https://github.com/WPIRoboticsProjec...Operation.java) ... basically everything in that main while() loop is the important stuff. CameraServer from WPIlibj works much the same way but utilizes NIVision.Image objects instead.

How you mash the two images together I don't know as I have basically zero experience with the NIVision libs. But, roll your own CameraServer, solve the issue of mashing images together into a single JPEG and there you go.

[Ozuru]

Awesome code, this snippet will surely be helpful in the future. Thanks for sharing.

[RamTech 59]

When I use this code my cameras seem to lag, does anyone have complete code that I can use as reference?

[kmodos]

Originally Posted by RamTech 59

When I use this code my cameras seem to lag, does anyone have complete code that I can use as reference?

Does the lag occur when you switch between the two? Switching will always lag a bit as well as all feeds will lag a tiny bit. Try to lower the quality of the returned image or lower the resolution.