Issues with running multiple (4) orbbec cameras - gemini2

[dhruvah]

I'm running into issues while running four cameras. I have a file that launches gemini2.launch, with the right namespaces, and a delay between the launches. All the camera nodes come up, and the logs show that everything is connected. I have all the serial numbers set correctly, so that is not an

But when I echo the topic for the fourth camera, it doesn't seem to publish any information.

This behavior is also inconsistent, and sometimes all the four cameras launch correctly with all the data being streamed.

I suspect that the error could be how the streaming is handled, based on the Subscriber callbacks. But I am not sure.

Has anyone run into a similar issue? This is my python launch file

#!/usr/bin/env python

import roslaunch
import rospy

rospy.init_node('multi_camera_launcher')
uuid = roslaunch.rlutil.get_or_generate_uuid(None, False)

launch = roslaunch.scriptapi.ROSLaunch()
launch.start()

front_up_depthcam = rospy.get_param('~front_up_depthcam', True)
back_up_depthcam = rospy.get_param('~back_up_depthcam', True)
front_down_depthcam = rospy.get_param('~front_down_depthcam', True)
back_down_depthcam = rospy.get_param('~back_down_depthcam', True)

device_num = rospy.get_param('~device_num', 4)

front_up_serial = rospy.get_param('~front_up_serial', '')
back_up_serial = rospy.get_param('~back_up_serial', '')
front_down_serial = rospy.get_param('~front_down_serial', '')
back_down_serial = rospy.get_param('~back_down_serial', '')

launch_file_path = '../src/orbbec_sdk_ros1/launch/gemini2.launch'

time_buffer = 3

def launch_camera(namespace, serial, device_num):
    cli_args = [
        launch_file_path,
        'camera_name:=' + namespace,
        'serial_number:=' + serial,
        'device_num:=' + str(device_num)
    ]
    roslaunch_args = cli_args[1:]
    roslaunch_file = [(roslaunch.rlutil.resolve_launch_arguments(cli_args)[0], roslaunch_args)]
    launch.parent = roslaunch.parent.ROSLaunchParent(uuid, roslaunch_file)
    launch.start()
    
 if front_up_depthcam:
    launch_camera('front_up', front_up_serial, device_num)

rospy.sleep(time_buffer)

if back_up_depthcam:
    launch_camera('back_up', back_up_serial, device_num)

rospy.sleep(time_buffer)

if front_down_depthcam:
    launch_camera('front_down', front_down_serial, device_num)

rospy.sleep(time_buffer)

if back_down_depthcam:
    launch_camera('back_down', back_down_serial, device_num)
    
launch.spin()

[dhruvah]

What seems to be an issue is that for the camera that is not working correctly pipeline_->start() in ob_camera_node.cpp doesn't seem to be working when startStreams() is called

[dhruvah]

The funny thing is that, this works perfectly fine for 3 cameras.

It has something to do when you start subscribing using a fourth camera, that it just doesn't work