code: def __update_offset_table(self, fileobj, fmt, atom, delta, offset):
          
          if atom.offset > offset:
              atom.offset += delta
          fileobj.seek(atom.offset + 12)
          data = fileobj.read(atom.length - 12)
          fmt = fmt % cdata.uint_be(data[:4])
          offsets = struct.unpack(fmt, data[4:])
          offsets = [o + (0, delta)[offset < o] for o in offsets]
          fileobj.seek(atom.offset + 16)
          fileobj.write(struct.pack(fmt, *offsets))
docs: Update offset table in the specified atom.