Fix build failed

fis/fis.Mac.csproj

@@ -26,5 +26,10 @@
    </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\fis.Vid\fis.Vid.csproj" />
-  </ItemGroup>   
+  </ItemGroup> 
+ <ItemGroup>
+    <Reference Include="FFMpegWrapper">
+      <HintPath>..\third_party\SmartPublisher\FFMpegWrapper.dll</HintPath>
+    </Reference>
+  </ItemGroup>  
 </Project>

fis/fis.Win.csproj

@@ -22,6 +22,11 @@
     <EmbeddedResource Include="flyinsono.ico">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </EmbeddedResource>
+  </ItemGroup>
+   <ItemGroup>
+    <Reference Include="FFMpegWrapper">
+      <HintPath>..\third_party\SmartPublisher\FFMpegWrapper.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Avalonia" Version="0.10.10" />