Function sixel_encoder_encode_bytes 

pub unsafe extern "C" fn sixel_encoder_encode_bytes(
    encoder: *mut Encoder,
    bytes: *mut c_uchar,
    width: c_int,
    height: c_int,
    pixelformat: PixelFormat,
    palette: *mut c_uchar,
    ncolors: c_int,
) -> Status