Notes

Gstreamer plugins enumerate all the channel/video devices for each of gst command. So, there might be chances that starting all channels with different gst process at same time do not allow the actual process to open the device and the process dedicated for the device does not start. For example, if all channels are opened immediately in a script, all the gst process open and close all the devices for all the channels and if somehow gst process 1 opens channel 2 and at same time if process 2 open channel 2, the 2 ^nd process do not get the channel 2 and returns, despite the process 1 do not require the channel 2 and close the channel 2 afterwards.  Adding sleep after every enumeration is required to make all applications work properly.