text: #_base_ = [
  #    '../_base_/models/retinanet_r50_fpn.py',
  #    '../_base_/datasets/coco_detection.py',
  #    '../_base_/schedules/schedule_1x.py', '../_base_/default_runtime.py'
  #]
  
  _base_ = [
      '../my_configs/_base_/models/retinanet_r50_fpn.py',
      '../my_configs/_base_/datasets/det_visdrone.py',
      '../my_configs/_base_/schedules/schedule_1x.py', 
      '../my_configs/_base_/default_runtime.py'
  ]
  
  
  # model settings
  norm_cfg = dict(type='GN', num_groups=32, requires_grad=True)
  model = dict(
      bbox_head=dict(
          _delete_=True,
          type='SABLRetinaHead',
          num_classes=10,
          in_channels=256,
          stacked_convs=4,
          feat_channels=256,
          approx_anchor_generator=dict(
              type='AnchorGenerator',
              octave_base_scale=4,
              scales_per_octave=3,
              ratios=[0.5, 1.0, 2.0],
              strides=[8, 16, 32, 64, 128]),
          square_anchor_generator=dict(
              type='AnchorGenerator',
              ratios=[1.0],
              scales=[4],
              strides=[8, 16, 32, 64, 128]),
          norm_cfg=norm_cfg,
          bbox_coder=dict(
              type='BucketingBBoxCoder', num_buckets=14, scale_factor=3.0),
          loss_cls=dict(
              type='FocalLoss',
              use_sigmoid=True,
              gamma=2.0,
              alpha=0.25,
              loss_weight=1.0),
          loss_bbox_cls=dict(
              type='CrossEntropyLoss', use_sigmoid=True, loss_weight=1.5),
          loss_bbox_reg=dict(
              type='SmoothL1Loss', beta=1.0 / 9.0, loss_weight=1.5)),
      # training and testing settings
      train_cfg=dict(
          assigner=dict(
              type='ApproxMaxIoUAssigner',
              pos_iou_thr=0.5,
              neg_iou_thr=0.4,
              min_pos_iou=0.0,
              ignore_iof_thr=-1),
          allowed_border=-1,
          pos_weight=-1,
          debug=False))
  # optimizer
  optimizer = dict(type='SGD', lr=0.01, momentum=0.9, weight_decay=0.0001)
  