Function gstreamer_video_sys::gst_buffer_add_video_bar_meta

pub unsafe extern "C" fn gst_buffer_add_video_bar_meta(
    buffer: *mut GstBuffer, 
    field: u8, 
    is_letterbox: gboolean, 
    bar_data1: c_uint, 
    bar_data2: c_uint
) -> *mut GstVideoBarMeta

This is supported on crate feature v1_18 only.