confirmed working with P/invoke on windows .NET Core C#

.gitignore

@@ -33,3 +33,6 @@
 
 # Build directory
 build/
+
+# VS stuff
+.vs/

CMakeLists.txt

@@ -16,6 +16,11 @@ project(dvmvocoder)
 set(CMAKE_STATIC_LIBRARY_PREFIX "")
 set(CMAKE_SHARED_LIBRARY_PREFIX "")
 
+# Set up export symbols (Windows only)
+if(WIN32)
+    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+endif()
+
 #
 # Build Vocoder as a Shared Library (dll or so)
 #

vocoder/MBEDecoder.cpp

@@ -16,7 +16,8 @@
 #include "MBEDecoder.h"
 
 using namespace edac;
-using namespace vocoder;
+
+namespace vocoder {
 
     // ---------------------------------------------------------------------------
     //  Constants
@@ -314,3 +315,29 @@ int32_t MBEDecoder::decode(uint8_t* codeword, int16_t samples[])
 
         return errs;
     }
+
+    // Extern methods for C#/C++ interop
+    MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode)
+    {
+        return new MBEDecoder(mode);
+    }
+
+    int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples)
+    {
+        if (pDecoder != NULL)
+        {
+            return pDecoder->decode(codeword, samples);
+        }
+        return -1;
+    }
+
+    void MBEDecoder_Delete(MBEDecoder* pDecoder)
+    {
+        if (pDecoder != NULL)
+        {
+            delete pDecoder;
+            pDecoder = NULL;
+        }
+    }
+
+} // namespace vocoder

vocoder/MBEDecoder.h

@@ -138,9 +138,17 @@ namespace vocoder
     };
 
     // Extern methods for C#/C++ interop
-    extern "C" MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode) { return new MBEDecoder(mode); }
-    extern "C" int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples) { return pDecoder->decode(codeword, samples); }
-    extern "C" void MBEDecoder_Delete(MBEDecoder* pDecoder) { delete pDecoder; }
+    extern "C" {
+#ifdef _WIN32
+        extern __declspec(dllexport) MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode);
+        extern __declspec(dllexport) int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples);
+        extern __declspec(dllexport) void MBEDecoder_Delete(MBEDecoder* pDecoder);
+#else
+        extern MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode);
+        extern int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples);
+        extern void MBEDecoder_Delete(MBEDecoder* pDecoder);
+#endif
+    }
 
 } // namespace vocoder
 

vocoder/MBEEncoder.cpp

@@ -44,12 +44,13 @@
 #include <cassert>
 
 using namespace edac;
-using namespace vocoder;
 
 #ifdef _MSC_VER
 #pragma warning(disable: 4244)
 #endif
 
+namespace vocoder {
+
     // ---------------------------------------------------------------------------
     //  Constants
     // ---------------------------------------------------------------------------
@@ -716,3 +717,24 @@ void MBEEncoder::encode(int16_t* samples, uint8_t* codeword)
             ::memcpy(codeword, dmrAMBE, 9U);
         }
     }
+
+    // Extern methods for C#/C++ interop
+    MBEEncoder* MBEEncoder_Create(MBE_ENCODER_MODE mode) 
+    { 
+        return new MBEEncoder(mode); 
+    }
+
+    void MBEEncoder_Encode(MBEEncoder* pEncoder, int16_t* samples, uint8_t* codeword)
+    {
+        if (pEncoder != NULL)
+        {
+            pEncoder->encode(samples, codeword);
+        }
+    }
+    
+    void MBEEncoder_Delete(MBEEncoder* pEncoder) 
+    { 
+        delete pEncoder; 
+        pEncoder = NULL;
+    }
+} // namespace vocoder

vocoder/MBEEncoder.h

@@ -81,9 +81,17 @@ namespace vocoder
     };
 
     // Extern methods for C#/C++ interop
-    extern "C" MBEEncoder* MBEEncoder_Create(MBE_ENCODER_MODE mode) { return new MBEEncoder(mode); }
-    extern "C" void MBEEncoder_Encode(MBEEncoder* pEncoder, int16_t* samples, uint8_t* codeword) { pEncoder->encode(samples, codeword); }
-    extern "C" void MBEEncoder_Delete(MBEEncoder* pEncoder) { delete pEncoder; }
+    extern "C" {
+#ifdef _WIN32
+        __declspec(dllexport) MBEEncoder* MBEEncoder_Create(MBE_ENCODER_MODE mode);
+        __declspec(dllexport) void MBEEncoder_Encode(MBEEncoder* pEncoder, int16_t* samples, uint8_t* codeword);
+        __declspec(dllexport) void MBEEncoder_Delete(MBEEncoder* pEncoder);
+#else
+        MBEEncoder* MBEEncoder_Create(MBE_ENCODER_MODE mode);
+        void MBEEncoder_Encode(MBEEncoder* pEncoder, int16_t* samples, uint8_t* codeword);
+        void MBEEncoder_Delete(MBEEncoder* pEncoder);
+#endif
+    }
 
 } // namespace vocoder