Raspivid Modification to Display Custom Message as Annotation on Video Feed (Local/Stream)

Raspivid Custom Annotations

Raspberry Pi distribution is equipped with an executable called raspivid/raspistill which is used to capture and view video/still images from the RPI's CSI camera. The source code for this is available on the internet.
It has various options like displaying video on HDMI, running TCP/UDP stream server, capability of reading encoded MP4 streams from the encoder, annotating the transmitted stream, automated still captures, effects, etc.
Annotations like an OSD label can be provided on the stream being transmitted. Time annotations, etc can be enabled on the stream/video feed.
The only drawback is that annotations are updated every second on the feed.
As there was a need to view various sensor information embedded in the video from a remotely operated vehicle, it would indeed be advantageous to extend raspivid capabilites.
As a quick modification was intended, the relevant files were changed to use an IPC (InterProcess Communication) mechanism and any program that would write its string into the IPC entity at approximately 1 second interval could send its information embedded on the video feed to the remote client.
A video showing the ultrasonic sensor reading on the front of a vehicle is being embedded in the network stream and is as shown in the video.

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