content: import os as __os  # add "__" if not want to be exported
  from copy import deepcopy as __deepcopy
  
  data_dir = f'{VL_DATA_DIR}'
  if data_dir is None:
      raise ValueError("please set environment `VL_DATA_DIR` before continue")
  
  data_root = __os.path.join(data_dir, "videos_images")
  anno_root_pt = __os.path.join(data_dir, "anno_pretrain")
  anno_root_downstream = __os.path.join(data_dir, "anno_downstream")
  
  # ============== pretraining datasets=================
  available_corpus = dict(
      # pretraining datasets
      cc3m=[
          f"{anno_root_pt}/cc3m_train.json", 
          "{your_data_root}"
      ],
      cc12m=[
          f"{anno_root_pt}/cc12m_train.json", 
          "{your_data_root}"
      ],
      sbu=[
          f"{anno_root_pt}/sbu.json", 
          "{your_data_root}"
      ],
      vg=[
          f"{anno_root_pt}/vg.json", 
          "{your_data_root}"
      ],
      coco=[
          f"{anno_root_pt}/coco.json", 
          "{your_data_root}"
      ],
      imagenet1k=[
          f"{anno_root_pt}/imagenet1k_train.json", 
          "{your_data_root}"
      ],
      webvid=[
          f"{anno_root_pt}/webvid_train.json", 
          "{your_data_root}",
          "video"
      ],
      webvid_10m=[
          f"{anno_root_pt}/webvid_10m_train.json",
          "{your_data_root}",
          "video",
      ],
      kinetics400=[
          f"{anno_root_pt}/kinetics400_train.json",
          "{your_data_root}",
          "video",
      ],
      kinetics710=[
          f"{anno_root_pt}/kinetics710_train.json",
          "{your_data_root}",
          "video",
      ],
      kinetics710_raw=[
          f"{anno_root_pt}/kinetics710_raw_train.json",
          "{your_data_root}",
          "only_video",
      ],
      internvid_10m_flt=[  
          f"{anno_root_pt}/internvid_10m_flt.json",
          "{your_data_root}",
          "video"
      ],
  )
  
  # composed datasets.
  available_corpus["coco_vg"] = [available_corpus["coco"], available_corpus["vg"]]
  available_corpus["in1k_k710"] = [
      available_corpus["imagenet1k"],
      available_corpus["kinetics710"],
  ]
  available_corpus["webvid_cc3m"] = [available_corpus["webvid"], available_corpus["cc3m"]]
  available_corpus["webvid_cc3m_in1k_k710"] = [
      available_corpus["webvid"], 
      available_corpus["cc3m"],
      available_corpus["imagenet1k"],
      available_corpus["kinetics710"],
  ]
  available_corpus["webvid_cc3m_k710raw"] = [
      available_corpus["webvid"], 
      available_corpus["cc3m"],
      available_corpus["kinetics710_raw"],
  ]
  available_corpus["webvid_14m"] = [
      available_corpus["webvid"],
      available_corpus["cc3m"],
      available_corpus["coco"],
      available_corpus["vg"],
      available_corpus["sbu"],
      available_corpus["cc12m"],
  ]
  available_corpus["webvid12m_14m"] = [
      available_corpus["webvid"],
      available_corpus["webvid_10m"],
      available_corpus["cc3m"],
      available_corpus["coco"],
      available_corpus["vg"],
      available_corpus["sbu"],
      available_corpus["cc12m"],
  ]
  available_corpus["webvid10m_14m"] = [
      available_corpus["webvid_10m"],
      available_corpus["cc3m"],
      available_corpus["coco"],
      available_corpus["vg"],
      available_corpus["sbu"],
      available_corpus["cc12m"],
  ]
  available_corpus["simple_17m"] = [
      available_corpus["webvid"],
      available_corpus["cc3m"],
      available_corpus["cc12m"],
  ]
  available_corpus["simple_25m"] = [
      available_corpus["webvid_10m"],
      available_corpus["cc3m"],
      available_corpus["cc12m"],
  ]
  available_corpus["viclip_20m"] = [
      available_corpus["internvid_10m_flt"],
      available_corpus["webvid_10m"],
  ]
  available_corpus["viclip"] = [
      available_corpus["internvid_10m_flt"],
  ]
  
  # ============== for validation =================
  available_corpus["msrvtt_1k_test"] = [
      f"{anno_root_downstream}/msrvtt_test1k.json",
      "{your_data_root}",
      "video",
  ]
  available_corpus["k400_act_val"] = [
      f"{anno_root_downstream}/kinetics400_validate.json",
      "{your_data_root}",
      "video",
  ]
  available_corpus["k600_act_val"] = [
      f"{anno_root_downstream}/kinetics600_validate.json",
      "{your_data_root}",
      "video",
  ]
  available_corpus["k700_act_val"] = [
      f"{anno_root_downstream}/kinetics700_validate.json",
      "{your_data_root}",
      "video",
  ]
  available_corpus["sthsthv1_act_val"] = [
      f"{anno_root_downstream}/sthsthv1_validate_clean2.json",
      "{your_data_root}",
      "video",
  ]
  available_corpus["sthsthv2_act_val"] = [
      f"{anno_root_downstream}/sthsthv2_validate_clean2.json",
      "{your_data_root}",
      "video",
  ]
  
  