code: def main(args):
      """Run the main decoding function."""
      parser = get_parser()
      args, extra = parser.parse_known_args(args)
      # logging info
      if args.verbose == 1:
          logging.basicConfig(
              level=logging.INFO,
              format="%(asctime)s (%(module)s:%(lineno)d) %(levelname)s: %(message)s",
          )
      elif args.verbose == 2:
          logging.basicConfig(
              level=logging.DEBUG,
              format="%(asctime)s (%(module)s:%(lineno)d) %(levelname)s: %(message)s",
          )
      else:
          logging.basicConfig(
              level=logging.WARN,
              format="%(asctime)s (%(module)s:%(lineno)d) %(levelname)s: %(message)s",
          )
          logging.warning("Skip DEBUG/INFO messages")
      if args.ngpu == 0 and args.dtype == "float16":
          raise ValueError(
              f"--dtype {args.dtype} does not support the CPU backend."
          )
      # check CUDA_VISIBLE_DEVICES
      device = "cpu"
      if args.ngpu == 1:
          device = "cuda"
          cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
          if cvd is None:
              logging.warning("CUDA_VISIBLE_DEVICES is not set.")
      elif args.ngpu > 1:
          logging.error("Decoding only supports ngpu=1.")
          sys.exit(1)
      # display PYTHONPATH
      logging.info(
          "python path = " + os.environ.get("PYTHONPATH", "(None)")
      )
      # recog
      logging.info("backend = " + args.backend)
      if args.backend == "pytorch":
          ctc_align(args, device)
      else:
          raise ValueError("Only pytorch is supported.")
      sys.exit(0)
  
file_path: espnet/espnet/bin/asr_align.py
imports: import json
  import logging
  import os
  import sys
  import configargparse
  import torch
  from ctc_segmentation import CtcSegmentationParameters, ctc_segmentation, determine_utterance_segments, prepare_text
  from espnet.asr.pytorch_backend.asr_init import load_trained_model
  from espnet.nets.asr_interface import ASRInterface
  from espnet.utils.io_utils import LoadInputsAndTargets
label_desc: Use image node_id 2 for calling a global function with example usage: main(args) without return types