Get media descriptor's user_data. user_data is specialized data
    accessed by the host application, VLC.framework uses it as a pointer to
    an native object that references a L{Media} pointer.
    @param p_md: media descriptor object.

def libvlc_media_get_user_data(p_md):
    '''Get media descriptor's user_data. user_data is specialized data
    accessed by the host application, VLC.framework uses it as a pointer to
    an native object that references a L{Media} pointer.
    @param p_md: media descriptor object.
    '''
    f = _Cfunctions.get('libvlc_media_get_user_data', None) or \
        _Cfunction('libvlc_media_get_user_data', ((1,),), None,
                    ctypes.c_void_p, Media)
    return f(p_md)