Hi,
i have seen "gen2-seq-num-sync" NOW my question is would it be possible to have multiple devices syncronised with each other, as this code only lets one camera synced together?

cheers

  • erik replied to this.

    Hello CodingArcher,
    another great question🙂 So this experiment uses sequence numbers of the frames to sync them. For multiple devices, instead of using packet.getInstanceNum(), you should use packet.getTimestamp(), as all devices have their time synced with the host computer, so it would be possible to sync all frames of all devices that way. I will actually add this to a TODO, as I believe it would be really useful for users with multiple cameras (such as yourself).
    Thanks, Erik

        Hi erik ,
        thank you so much for the prompt feedback.
        That actually makes so much sense to use the host timestamp to sync them all together.
        I was getting bit confused as the new updated version on github now has 3 cameras enabled but now the code it much more complicated then prior with two. 😮

        Also i am certain that it should be possible to be able to detect is the device is a OAK-D or OAK-1 as one has 3 cameras and the other only 1 thus the code would need to be able to adjust to this and not break due to uncertain circumstances?

        Cheers,
        Markus

        • erik replied to this.

            Hello CodingArcher, glad to help! It depends on the use-case; if using only 1 device, it's easier to sync by the sequence number, if using multiples timestamp is the way to go. And yes, you can get available cameras of the device (device.getConnectedCameras()), so you can check beforehand if you can simplify syncing.
            Thanks, Erik

                Hi erik ,
                you are truly a wise man. Thank you for sharingall of your knowledge and helping em get to the right direction 🙂

                cheers,
                markus

                  hi @erik ,
                  i had some testing and this is how far i have gotten sofar with getting multiple cameras connected with sync. Sadly it hasnt been far as im yet to understand how the getTimestamp has to be implemented for each camera to know the precise time...

                  
import cv2
import depthai as dai
import contextlib

# Start defining a pipeline
pipeline = dai.Pipeline()

cam_list = ['left', 'rgb', 'right']
cam_socket_opts = {
    'rgb'  : dai.CameraBoardSocket.RGB,
    'left' : dai.CameraBoardSocket.LEFT,
    'right': dai.CameraBoardSocket.RIGHT,
}
cam_instance = {
    'rgb'  : 0,
    'left' : 1,
    'right': 2,
}

cam = {}
xout = {}
for c in cam_list:
    xout[c] = pipeline.createXLinkOut()
    xout[c].setStreamName(c)
    if c == 'rgb':
        cam[c] = pipeline.createColorCamera()
        cam[c].setResolution(dai.ColorCameraProperties.SensorResolution.THE_1080_P)
        cam[c].setIspScale(720, 1080)  # 1920x1080 -> 1280x720
        cam[c].isp.link(xout[c].input)
    else:
        cam[c] = pipeline.createMonoCamera()
        cam[c].setResolution(dai.MonoCameraProperties.SensorResolution.THE_720_P)
        cam[c].out.link(xout[c].input)
    cam[c].setBoardSocket(cam_socket_opts[c])
    cam[c].setFps(30)



# https://docs.python.org/3/library/contextlib.html#contextlib.ExitStack
with contextlib.ExitStack() as stack:
    for device_info in dai.Device.getAllAvailableDevices():
        device = stack.enter_context(dai.Device(pipeline, device_info))
        print("Conected to " + device_info.getMxId())

    while True:

        if cv2.waitKey(1) == ord('q'):
            break
                  • erik replied to this.

                    hi erik ,
                    thats amazing. thanks for the link. ill check it out. looking forward to see how someone else implements it also

                      2 years later

                      erik Did you manage to do the TODO, do you have a link to it. I am also interested in syncing several cameras.

                        erik Thanks a lot. Yes that is putting me on the right track thanks a lot.