Native library

MisbCoreNative Lib is a MisbCore compiled as a self-contained native library (Native AOT Form Factor).
This library allows easy integration into C/C++ cross-platform applications.

System Requirements

OS: Windows / Linux (x64 or arm64).

Using MisbCoreNative Lib

To use the library, we first have to load it:

#ifdef _WIN32
    #define funcAddr GetProcAddress
    const char* PathToLibrary = "C:\\work\\MisbCoreNativeLib.dll";
    HINSTANCE handle = LoadLibraryA((char*)PathToLibrary);
#else
    #define funcAddr dlsym
    const char* PathToLibrary = "/home/user/work/MisbCoreNativeLib.so";
    void* handle = dlopen((char*)PathToLibrary, RTLD_LAZY);
#endif

Encoding RAW KLV buffer

Now, let's create a very simple MISB 601 Local set packet (sample data from MISB ST 0601.16a).

const char* jspnPckt = R"({
    2: '2008-10-24T00:13:29.913',
    3: 'MISSION01',
    13: 60.176822966978335,
    14: 128.42675904204452,
    15: 14190.7195,
    16: 144.571298,
    65: 13
})";

Next, we will define a simple structure that accommodates the resulting buffer and its length and call Encode method, passing the string as an argument.

struct PcktBuffer
{
    char* buffer;
    int length;
};

typedef PcktBuffer (*encodeFunc)(char*);

encodeFunc encode601Pckt = (encodeFunc)funcAddr(handle, (char*)"Encode");

// Encode json packet to data buffer
PcktBuffer pcktBuf = encode601Pckt((char*)(jspnPckt));

Note, the Encode function returns a pointer to an internally allocated memory. It will be automatically de-allocated during the next Encode call, so you may need to copy this buffer (depending on the scenario).

The resulting buffer is a RAW Klv that comprises all mandatory parts of the packet:

• The UAS Local Set 16-Byte UL “Key”
• Packet length
• Packet data payload
• Checksum

This buffer can be injected into STANAG4609 multiplex:

Timestamps

If you don't provide a mandatory Tag 2 timestamp, MisbCore will add a current time automatically.
Time can be set as a long value (as specified in MISB601 standard) - "2": 1638730169255332, or as an ISO 6601 string, for example - "2": "2021-12-16T13:44:54")

Decoding RAW KLV buffer

To decode the data buffer:

typedef char* (*decodeFunc)(char*, int len);

decodeFunc decodeKlvBuffer = (decodeFunc)funcAddr(handle, (char*)"Decode");

// Decode the buffer back to json. 
char* json = decodeKlvBuffer((char*)buf, len);

Here is the result:

{
  "2": "2008-10-24T00:13:29.913Z",
  "3": "MISSION01",
  "13": 60.176822967,
  "14": 128.426759042,
  "15": 14190.72,
  "16": 144.5713,
  "65": 13,
  "1": 53482
}

Converting to a detailed human-readable format

This method may be used for presentation, when you need some additional information, like tag full name in addition to the tag number and more suitable value formatting.

typedef char* (*toDetailedFunc)(char*);
toDetailedFunc toDetailed = (toDetailedFunc)funcAddr(handle, (char*)"ToDetailed");

char* detailedJsonStr = toDetailed((char*)jsonPckt);
printf("Convert a compact json format to human readable, detailed json: \n %s", detailedJsonStr);

The resulting string will be something like this:

{
  "003. Mission ID": "MISSION01",
  "004. Platform Tail Number": "AF-101",
  "005. Platform Heading Angle": "159.974365°",
  "006. Platform Pitch Angle": "-0.43°",
  "007. Platform Roll Angle": "3.41°",
  "008. Platform True Airspeed": "147 m/s",
  "009. Platform Indicated Airspeed": "159 m/s",
  "010. Platform Designation": "MQ1-B",
  "011. Image Source Sensor": "EO",
  "012. Image Coordinate System": "WGS-84",
  "013. Sensor Latitude": "60° 10' 36.563'' N",
  "014. Sensor Longitude": "128° 25' 36.333'' E",
  "015. Sensor True Altitude": "14190.7195 m",
  "016. Sensor Horizontal field of View": "144.571298°",
  "017. Sensor Vertical Field of View": "152.643626°",
  "018. Sensor Relative Azimuth Angle": "160.7192°",
  "019. Sensor Relative Elevation Angle": "-168.7923°"
  ...
}

Cleaning up

To free internally allocated memory, call CleanUp method:

typedef void (*cleanUpFunc)();

cleanUpFunc cleanUp = (cleanUpFunc)funcAddr(handle, (char*)"CleanUp");
cleanUp();

Using multiple instances

It is possible to get multiple encoder/decoder instances.
To achieve this, use the following methods:

typedef PcktBuffer (*instanceEncodeFunc)(int id, char*);
typedef char* (*instanceDecodeFunc)(int id, char*, int len);
typedef void (*instanceCleanUpFunc)(int id);

The only difference from the default mode is that you have to provide an instance id as an argument.

Note, in non default mode, the instance is created and activated on a first call to instanceEncodeFunc or instanceDecodeFunc.

Here is an example of using instance with id=1.

PcktBuffer pcktBuf = encode601Pckt(1, (char*)(jspnPckt)); 
char* json = decodeKlvBuffer(1, (char*)(pcktBuf.buffer), pcktBuf.length);

Demo mode

Please note that if not activated, the library will work in demo mode processing only tags < 15 (and tag 65).
To activate the license, call Activate method:

const char* PathToLicenseFile = "/home/user/Licenses/Impleo/MisbCoreNativeLicense.lic";
const char* LicenseKey = "AF596BF0-BBAB142B-1B905B24-8DA51BED";
typedef bool (*activateFunc)(char*, char*);

activateFunc Activate = (activateFunc)funcAddr(handle, (char*)"Activate");
bool fValid = Activate((char*)PathToLicenseFile, (char*)LicenseKey);

Demo app

A simple demo app (cmake project) that demonstrates the basic functionality is available (MisbCoreNativeLib-demo.zip).

Getting help

To get help with MisbCoreNative Lib, please contact us at support@impleotv.com.