code: def _read_annot_ctab_old_format(fobj, n_entries):
      """Read in an old-style Freesurfer color table from `fobj`.
  
      Note that the output color table ``ctab`` is in RGBT form, where T
      (transparency) is 255 - alpha.
  
      This function is used by :func:`read_annot`.
  
      Parameters
      ----------
  
      fobj : file-like
          Open file handle to a Freesurfer `.annot` file, with seek point
          at the beginning of the color table data.
      n_entries : int
          Number of entries in the color table.
  
      Returns
      -------
  
      ctab : ndarray, shape (n_entries, 5)
          RGBT colortable array - the last column contains all zeros.
      names : list of str
          The names of the labels. The length of the list is n_entries.
      """
      assert hasattr(fobj, "read")
  
      dt = _ANNOT_DT
      # orig_tab string length + string
      length = np.fromfile(fobj, dt, 1)[0]
      orig_tab = np.fromfile(fobj, ">c", length)
      orig_tab = orig_tab[:-1]
      names = list()
      ctab = np.zeros((n_entries, 5), dt)
      for i in range(n_entries):
          # structure name length + string
          name_length = np.fromfile(fobj, dt, 1)[0]
          name = np.fromfile(fobj, "|S%d" % name_length, 1)[0]
          names.append(name)
          # read RGBT for this entry
          ctab[i, :4] = np.fromfile(fobj, dt, 4)
  
      return ctab, names
  
file_path: nibabel/nibabel/freesurfer/io.py
imports: import getpass
  import time
  import warnings
  from collections import OrderedDict
  import numpy
  from ..openers import Opener
label_desc: Use image node_id 10 for calling a global function with example usage: _read_annot_ctab_old_format(fobj, n_entries) and returns: ctab,  names