H265 Encoding Error with VLC 2.2

[Tabascal]

I am using VLC 2.2 64 bit Win 8.1 .
When I am trying to encode an .MP4 file to H265 file using the convert /save option. I am getting the error below:

Streaming / Transcoding failed:
It seems your Libav/FFmpeg (libavcodec) installation lacks the following encoder:
MPEG-H Part2/HEVC (H.265).
If you don't know how to fix this, ask for support from your distribution.

I am also getting the same error when I am using VLC 2.2, 32 bit, Win VISTA.

I am missing something here.

[Jean-Baptiste Kempf]

You need to add venc=x265

[Tabascal]

Thank you very much. Since I am new to this could you help me by letting me know where to pass on this venc=x265" string in vlc 64 bit win 8.1