2010 FRC Camera Live Feed Lag

[ideasrule]

OK, here's what I just tried:

Setting battery options to "Always On".
Running the driver station software under the Developer account.
Running the software with the Dashboard selected.
Logging on to only one account at a time.
Using a laptop as the driver station.
Setting the camera's frame rate to 5 frames/sec.

None of the above had an appreciable effect on the lag. Help!

[TheDominis]

Originally Posted by ideasrule

OK, here's what I just tried:

Setting battery options to "Always On".
Running the driver station software under the Developer account.
Running the software with the Dashboard selected.
Logging on to only one account at a time.
Using a laptop as the driver station.
Setting the camera's frame rate to 5 frames/sec.

None of the above had an appreciable effect on the lag. Help!

Increase FPS? I don't know what you mean by lag. You are only going to get a new image every 200ms at that speed....

[ideasrule]

The problem is that I'm NOT getting one frame every 200 ms. I'm getting one frame every 500 ms. If I were getting 5fps, I'd be happy.

[Patrickwhite]

Well, we found *a* problem. We had been using the driver account on the ClassMate as the driver station, silly us, of course it's not designed for that exact purpose. When we logged off the driver account and switched to the developer account, the frame rate jumped up by a factor of ten or twenty (on 320x240 resolution), and the lag all but disappeared. What worries us now is we don't know whether this will be allowed at the competition (looked through the competition documents). Does anyone else have this problem and/or have a solution, or know if the Developer account will be allowed for use at the competition?

[ideasrule]

The story behind this is interesting. Patrick suggested using the developer account to test the camera feed. By chance, I was busy doing something and couldn't tell him he was being stupid because I'd already tried that (which I did). By chance, I had changed the image resolution from 640x480 to 320x240. Against all odds, these two unlikely events happened at the same time and led to our strange discovery. (I changed the resolution back to 640x480 and the lag time became the familiar 1/2 s.)

Another possibly useful piece of info is that I was using the code to test the frame rate by measuring the time it took to get 300 fresh images. We got 5 fps on 640x480, 21 fps on 320x240, and 30 fps on 160x120. However, the live feed was certainly not operating at 5 fps at a resolution of 640x480, regardless of the account used. It always operated at 2 fps.

[Mr. Lim]

We can confirm the behaviour that 610 is seeing. We get about 2 fps on the DS display, but there is a delay on top of that. The frames update at 2fps, but the frames we see are also more than 1s in the past. We notice this poor performance in the Driver account, even with 160x120 resolution frames.

Strangely, increasing the resolution does not seem to slow the framerates on the DS. In some cases the DS display updated faster on 640x480 than on 160x120.

However, the rate in which the cRIO processed the image was considerably faster with the small resolution.

[jhersh]

Is the lag and frame rate in your system impacted at all by running wired vs. wireless?

[TheDominis]

2 FPS is consistent with my benchmarks over in the C++ forums.

http://www.chiefdelphi.com/forums/sh...ad.php?t=80591

[tutkows1]

We are haveing the same problem also, are your saying a quick fix for this problem is to run the driverstation under the developer account?

[dmlawrence]

Same problem here as well

[Radical Pi]

I found the problem to be the graphs on the right side of the dashboard were causing a huge delay. I removed them and we now get near instant video (minus expected network latency). Our fixed dashboard is here http://www.chiefdelphi.com/forums/sh...ad.php?t=81378

[Radical Pi]

http://www.chiefdelphi.com/forums/sh...ad.php?t=81378

/\ is our solution. The graphs on the right side of the Dashboard were lagging the image considerably so we took them out of the Dashboard and the image is very fast now (only the expected network latency). The fixed Dashboard is attached

[Damaku250]

What do you guys mean by "logging into the camera?" Is it the Axis Camera setup? Or are we talking about logging in by navigating to its IP address (and what would that be if this is the case)?

[cheesepuffgd]

I have had that problem with the camera feed. We are using the lowest resolution, we are running it in the developer account with nothing else open. it is programmed in C++. Is there anything I can do about this?

[Greg McKaskle]

Are you using the new update for C++? The second issue that can cause lag is that the driver station is bogged down. You can check with the task manager.

Greg McKaskle