Capture from two cameras frames on sync

Hi,

We are developing an application called SyncSnap, the idea is to be able to capture from two or more cameras frames on sync, with the less time possible between the frames. We are getting good numbers but I was wondering if there is a mode on nvcamerasrc or libargus that we could use to improve more the synchronization. Does NVIDIA has a combination of property values or environment variables that we could set such that several nvcamerasrc instances would capture on sync? This would help us to improve the times that we are getting:

Specially on the very first set of images.

-David

Hi DavidSoto,

Is the result (https://developer.ridgerun.com/wiki/index.php?title=SyncSnap_Application#Testing_Results) based on hw fsync cameras?

You can refer to syncSensor (~/tegra_multimedia_api/argus/samples/syncSensor) in samples of MM APIs to see if help.

Hi vickyy,

   Thanks for your reply. Could you elaborate a little bit more on hw fsync cameras? I am not sure to what you are referring to. I will review syncSensor as well.

“HW fsync cameras” sounds to me like cameras that use a hardware sync cable. Many sensors have a separate input signal that can tell them to start, but it’s often not brought out on camera boards, and even if it is, you need to wire up a GPIO of some sort to actually start it.

Hi Snarky,

Yes, that is my guess too, thanks for your help. I just wanted to check if that is what NVIDIA would recommend too or if the TX1 had a special feature to handle these scenarios.

Hi DavidSoto,

No, we don’t have special feature to handle frame sync use case, just the syncSensor sample as reference, we’re curious how you got the test result in your wiki.
Regarding the HW sync, that will required synchronization mechanism support on the sensor, and enable it on that board design, currently no plan to do that in NVIDIA side, but you could check with our camera partner whether they implemented it or not.

Thanks

Hi,

We were basically capturing a stopwatch in a monitor from all the cameras and checked the value. We are talking with e-consystems they seem to have one camera for that (e-CAM30_HEXCUTX1). We will run the syncsnap test there and report the new values.

-David