def build_dla_fpn5_backbone(cfg, input_shape: ShapeSpec):
    """
    Args:
        cfg: a detectron2 CfgNode
    Returns:
        backbone (Backbone): backbone module, must be a subclass of :class:`Backbone`.
    """

    depth_to_creator = {"dla34": dla34}
    bottom_up = depth_to_creator['dla{}'.format(cfg.MODEL.DLA.NUM_LAYERS)](cfg)
    in_features = cfg.MODEL.FPN.IN_FEATURES
    out_channels = cfg.MODEL.FPN.OUT_CHANNELS
    in_channels_top = bottom_up.output_shape()['dla5'].channels

    backbone = FPN(
        bottom_up=bottom_up,
        in_features=in_features,
        out_channels=out_channels,
        norm=cfg.MODEL.FPN.NORM,
        top_block=LastLevelP6P7(in_channels_top, out_channels),
        fuse_type=cfg.MODEL.FPN.FUSE_TYPE,
    )

    return backbone

    Args:
        cfg: a detectron2 CfgNode
    Returns:
        backbone (Backbone): backbone module, must be a subclass of :class:`Backbone`.
    
video_chat_text/video_chat_with_MOSS/models/grit_src/third_party/CenterNet2/projects/CenterNet2/centernet/modeling/backbone/dlafpn.py