Go to Tools -- Preferences -- (Show settings ALL in the bottom left corner)
Scroll down to "Inputs/Codecs"
Open Access Module list
Select Direct Show
Video device name, copy the name of the device your previously copy
Picture aspect-ratio n:m (enter your aspect ratio e.g.: 4:3, 16:9, 16:10)
From the windows command-line CTRL+R
Type CMD + ENTER
Type de following command: cd C:\Program Files (x86)\VideoLAN\VLC (assuming you have installed vlc in the default path. If not right-click on vlc icon and select properties. Copy the target and paste it in command prompt following the cd command.
Copy paste the following command: vlc dshow:// --fullscreen (VLC should open in full screen and capture your video device)
In order to change from landscape to portrait mode add the following argument to your command: --transform-type=90 --video-filter "transform{true}"
To launch VLC at startup unzip the archive and copy/paste the batch file in the Windows startup folder