code: def test_au(h, f):
      """AU and SND files"""
      if h.startswith(b".snd"):
          func = get_long_be
      elif h[:4] in (b"\0ds.", b"dns."):
          func = get_long_le
      else:
          return None
      filetype = "au"
      hdr_size = func(h[4:8])
      data_size = func(h[8:12])
      encoding = func(h[12:16])
      rate = func(h[16:20])
      nchannels = func(h[20:24])
      sample_size = 1  # default
      if encoding == 1:
          sample_bits = "U"
      elif encoding == 2:
          sample_bits = 8
      elif encoding == 3:
          sample_bits = 16
          sample_size = 2
      else:
          sample_bits = "?"
      frame_size = sample_size * nchannels
      if frame_size:
          nframe = data_size / frame_size
      else:
          nframe = -1
      return filetype, rate, nchannels, nframe, sample_bits
  
file_path: catboost/contrib/tools/python3/src/Lib/sndhdr.py
imports: import warnings
  from collections import namedtuple
label_desc: Use image node_id 4 for calling a global function with example usage: test_au(h, f) and returns: filetype,  rate,  nchannels,  nframe,  sample_bits, None