函数 av_read_image_line 

pub unsafe extern "C" fn av_read_image_line(
    dst: *mut u16,
    data: *mut *const u8,
    linesize: *const c_int,
    desc: *const AVPixFmtDescriptor,
    x: c_int,
    y: c_int,
    c: c_int,
    w: c_int,
    read_pal_component: c_int,
)