I use VS2013 to build this plugin , it seems there are many compatibility issues when you use VS2015 (you can google "legacy_stdio_definitions.lib").Great plugin and thanks for the source code!
Is there any instruction for compiling the code? Get stuck in VS 2015 with some link errors:
Error LNK2001 unresolved external symbol __imp___vsnprintf obs-virtualsource E:\project\c\obs-virtual-cam\build\src\virtual-source\strmbasd.lib(dllsetup.obj) 1
Error LNK2019 unresolved external symbol _obs_frontend_push_ui_translation referenced in function _obs_module_load obs-virtualoutput E:\project\c\obs-virtual-cam\build\src\virtual-output\virtual_output.obj 1
If you really want to run in VS2015 , maybe you should build strmbase lib by VS2015 first , you can find it in windows 7 SDK example (multimedia/directshow/baseclasses/)
Also the error message shows the project do not link to obs.lib or obs-frontend-api.lib , you should check your linker input.