freeD

A simple freeD tracking protocol implementation written in golang

What is freeD?

freeD is a very simple protocol used to exchange camera tracking data. It was originally developed by BBC R&D and is now supported by a wide range of hard- and software including Unreal Engine, disguise, stYpe, Mo-Sys and Panasonic.

You can find some documentation by Vinten that includes a deeper look into the protocol here: https://www.manualsdir.com/manuals/641433/vinten-radamec-free-d.html

Note that the original system is designed to transmit its data via RS232 or RS422. See manual section A.3 to get a detailed look of what's going on.

If you need support or have a idea to make this library better, don't hesitate to contact me... :)

Install

go get github.com/stvmyr/freeD

Functions

freeD.Decode()

Decode takes a byte array (typically received via UDP nowadays), parses the data and returns a freeD struct and error. Only if the Internal checksum validation failes, an error is returned.

freeD.Encode()

Encode takes a freeD struct as described below, and generates a byte array in the freeD format. This array can then transmitted via UDP.

FreeD struct

type FreeD struct {
	Pitch float32
	Yaw   float32
	Roll  float32
	PosZ  float32
	PosX  float32
	PosY  float32
	Zoom  int
	Focus int
}

FreeD Protocol

A typical freeD package contains 29 Bytes:

Offset	Function	Description
0	Identifier	Message Type. The Encode function always uses 0xD1. (see freeD manual section A.3.1 for further information)
1	ID	Camera ID. This is a relict when using multiple Systems via RS232 or RS422.
2:5	Pitch	Camera Pitch angle described in degree.
5:8	Yaw	Camera Yaw angle described in degree.
8:11	Roll	Camera Roll angle described in degree.
11:14	Position Z	Camera Z Offset from origin. Typically described in millimeter.
14:17	Position Y	Camera Y Offset from origin. Typically described in millimeter.
17:20	Position X	Camera X Offset from origin. Typically described in millimeter.
20:23	Zoom	Lens Zoom Position. Typically measured with an external encoder attached to the Lens. In the most cases this is a value between 0-4095.
23:26	Focus	Lens Focus Position. Typically measured with an external encoder attached to the Lens. In the most cases this is a value between 0-4095.
26:28	Reserved	Currently not used in freeD.
28	Checksum	Checksum of the first 28 bytes. The Decode function uses the checksum to verify if the incoming data is a valid freeD package.