code: def _convert_velodyne_to_pcd(
      velodyne_map,
      calib_map,
      pcd_dir,
      uuids,
      overwrite=False,
      num_workers=None,
  ):
      inputs = []
      for uuid in uuids:
          velodyne_path = velodyne_map[uuid]
          calib_path = calib_map[uuid]
  
          outname = (
              os.path.splitext(os.path.basename(velodyne_path))[0]
              + ".pcd"
          )
          pcd_path = os.path.join(pcd_dir, outname)
  
          if overwrite or not os.path.isfile(pcd_path):
              inputs.append((velodyne_path, calib_path, pcd_path))
  
      if not inputs:
          return
  
      etau.ensure_dir(pcd_dir)
  
      logger.info("Converting Velodyne scans to PCD format...")
      num_workers = fou.recommend_process_pool_workers(num_workers)
      with fou.ProgressBar(total=len(inputs)) as pb:
          with fou.get_multiprocessing_context().Pool(
              processes=num_workers
          ) as pool:
              for _ in pb(pool.imap_unordered(_do_conversion, inputs)):
                  pass
  
imports: import csv
  import logging
  import struct
  import os
  import numpy
  import eta.core.utils
  import eta.core.web
  import fiftyone
  import fiftyone.core.labels
  import fiftyone.core.metadata
  import fiftyone.core.storage
  import fiftyone.core.utils
  import fiftyone.utils.data
label_desc: Use image node_id 14 for calling a global function with example usage: _convert_velodyne_to_pcd(velodyne_map, calib_map, pcd_dir, uuids, overwrite, num_workers) without return types