One note : I found out a command dumpbin, so now I see, that exported symbols are :
h264_ptplugin.dll
OpalCodecPlugin_GetCodecs
PWLibPlugin_GetAPIVersion
libx264-114.dll
828 functions exported...
and when I tried to use it on ffmpeg libraries, the link.exe crashed (I'm not sure, whether it points out that ffmpeg was not build correctly or not).
anyway, at least concerning the h264plugin, symbols seems to be exported correctly so I would expect i should see the capability (or at least a crash would be nice, so I know it does something)
V.