This appears to be a fixed-point (rather than a floating-point) format.
If you treat the 64-bit values as signed integers and divide by 4398046511104.0, you will get the decimal values you show.
e.g. the following will print -9999
int64_t x = 0xFF63C40000000000LL;
double y = x / ...
It is a bit unclear what do you mean by "library being called". If you want to know when the library is loaded, you may look for references to System.loadLibrary(string) or System.load(string) java functions. You might for example hook it using Frida.
If you want to see when particular functions exported by the libusbhost.so are called, you also ...
You have two possible approaches in here:
Analyze the APK of the device, reverse engineer it and try to make sense of how it communicates with the USB device.
Connect the USB device to a computer, sniff the USB packets, and try to make sense of how it communicates with the host.
I believe the former would be straightforward and simpler than the latter, not ...
As expected, the USB was indeed detected but due that Linux has no idea how to deal with it without a proper driver, it only parses its hardware related parameters (Vendor and Product IDs) and stops there.
Here are the USB device's entries in usb-devices and lsusb commands respectively:
T: Bus=01 Lev=02 Prnt=05 Port=00 Cnt=01 Dev#= 8 ...
First I would find the h/w device ID from device manager. i.e. USB\VID_045E&PID_0766. In some cases you can find existing open source drivers for closely matching device IDs and make them work with minimal modifications.
Is the application actually installing 3rd party drivers, the two drivers you mention ksthunk.sys and usbvideo.sys are Microsoft ...
First, try to identify the components of the device. If it's cheap, buy a second one and crack it open.
Look for specifications and find similar devices which have the same specs. It's not like this device is the only one on the planet with that imaging sensor. That may help you find a compatible driver or spec from which to start your implementation.
Almost any Arduino is capable of USB communication (at least low speed). There is difference if you need software (for example V-USB) or it has hardware support. Unless your board has dedicated USB output (which usually also mean hardware support) you also need to make required connector to USB cable (watch for appropriate signal voltage level (3.3 V)). And ...