A lightweight Python implementation of the FreeD protocol.
freed.py contains some objects to help interface with FreeD structures. In particular are the ThreeBytes and ThreeBytesSigned types which define a fixed width integer type of 24 bits that is used in many of the FreeD protocols message payloads. This helps prevent errors like integer overflows.
Units are as follows: Position is millimetres * 1/64 Angle is degrees * 1/32768
The FreeDWrapper object can be used to create and set up a 0xD1 Position Poll command to send to a FreeD unit/camera (such as with Unreal Engine's LiveLink plugin). This will take regular python ints and bounds check them. Use the createFreeD() method to create an object with raw byte fields, and then use the encode() method on that object to serialise it to a byte array that can be sent over the protocol of your choice (such as UDP).
# pitch, yaw, roll, posz, posy, posx, zoom, focus
newcameraposition = FreeDWrapper(0 , 0, 0, 25000, 1000, -5000, 128, 300)
message = newcameraposition.createFreeD() #adds message metadata + checksum.
message.cameraid = b'\0x01' #Select a camera to send command to - by default this is 0xFF (all cameras).
bytes = message.encode()
# Do things with the bytes..
senddata(bytes)Includes an example program that turns keyboard inputs into FreeD data and pipes them over a UDP socket on localhost:40000. The example program relies on Python 3.10 and a Windows terminal.