View source for ML-TN-005 — Real-time Social Distancing and video streaming on Orca SBC

=Implementation=
==Camera modules interfacing==
The camera modules are connected to the MIPI CSI-2 ports of the i.MX8M Plus. Each one exploits 4 MIPI lanes.

The camera modules are configured as follows:
*camera module #1 (daA2500-60mc)
** resolution: 640x360
**frame rate: 15fps
*camera module #2 (daA3840-30mc)
** resolution: 1280x720
**frame rate: 30fps

==Video streams processing==

=== Stream #1 ===
Camera #1 stream is the one processed by the Social Distancing (SD) algorithm, which is described in detail in [[ML-TN-002_-_Real-time_Social_Distancing_estimation|this document]]. As such, this stream is fed to an NPU-powered neural network. This stream is also color space converted to fulfill the input requirements of the network. In order to offload the ARM Cortex-A53 cores, the conversion is performed by the GPU. 

The output stream of the SD algorithm is hardware-encoded before being streamed over a Gigabit Ethernet connection. On the Orca SBC #2 side, the stream is hardware-decoded and visualized on a HDMI monitor. 

===Stream #2===
Stream #2 originates at the daA3840-30mc camera module. Then, it is hardware-encoded and streamed by the Orca SBC #1. Finally, it is received by the Orca SBC #2, which hardware decodes and displays it.
==GUI application==
A GUI application runs on the Orca SBC #2 as well. This application is engineered with [https://www.cranksoftware.com/storyboard Crank Storyboard 6] and shows some parameters of the Social Distancing algorithm while it operates. The GUI application remotely communicates with the Social Distancing application — which is written in Python — through [https://resources.cranksoftware.com/cranksoftware/v5.3.0/docs/webhelp/index.html#ww_sbio.html Storyboard IO API]. According to official documentation, ''the Storyboard IO API, formerly known as GREIO, provides a platform independent communication API that allows inter-task and inter-process queued message passing. This is primarily used to allow external communication with a Storyboard application''. For more details, please see [https://support.cranksoftware.com/hc/en-us/articles/360056943752-Receiving-Events-from-a-Storyboard-Application this article].