OpenHD
Describe the software we used for the live video, how it works, and why we decided to use it in comparison to other systems like FPV drone systems etc...
To preface, I'll first explain how regular wifi works and then explain how OpenHD works.
When you use Wi-Fi on a device, your device is constantly receiving packages of data from the Wi-Fi modem. These packages hold the data needed to refresh pages, work applications, etc...
This process has 4 steps:
The modem sends the packages to your device
Your device receives/does not receive the package
Your device sends a signal back to the modem verifying that the package was received.
If the package was not received, the modem sends the package again and continues with other packages.
This process works well for devices like phones and laptops, where you need everything to be loaded properly. It is a connection-focused system that ensures you receive all of the packages that you need to run your application. For example, when running a website, package loss could mean that the website won't load properly or, in extreme cases, won't load at all.
In a system like live video, where it is more important to get the current frame rather than the frame that we should have gotten 2 seconds ago, it's more important to prioritize receiving current data rather than receiving all data. This is where OpenHD comes in.
OpenHD puts Wi-Fi into a state where the modem sends data regardless of verification. This significantly reduces latency in data transfer but also makes the stream of data you receive less reliable, where if you lose connection, all packages will be lost, and you will not be able to get any data.
More information about OpenHD can be found here: https://openhdfpv.org/
In the end, OpenHD was selected because it allows reliable video transfer over long distances and is an easy software to use.
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