fixed bug when no cod_opts are given and simplified function

import logging

import os.path

import platform

import re

from itertools import repeat

from pathlib import Path

from shutil import copyfile

        # in case of LFE 9.6 kbps NB processing strip any "-max_band XX" from cmd.extend and amend by "-max_band NB"

        if proc_chan_lfe_9k6bps_nb is True:

            cod_opts = []

            # search for -max_band XXX

            regex = re.compile(r"-max_band.*", re.I)

            last_was_max_band = False

            for i in self.cod_opts:

                # the additional arguments are expected in form of a list, where "-max_band" are "SWB" are two entries

                # then when we have detected "-max_band" in the previous run, we have to skip i again

                if last_was_max_band is True:

                    last_was_max_band = False

                    continue

                if regex.match(i):

                    last_was_max_band = True

            if self.cod_opts:

                cod_opts = self.cod_opts

                # for finding index of max_band entry use lower case version

                cod_opts_lower = [x.lower() for x in self.cod_opts]

                if "-max_band" in cod_opts_lower:

                    idx_max_band = cod_opts_lower.index("-max_band")

                    # use original version and not lower case version due to possible paths in there

                    cod_opts[idx_max_band+1] = "NB"

            else:

                    cod_opts.append(i)

                    last_was_max_band = False

            # add -max_band NB

            cod_opts.append("-max_band")

            cod_opts.append("NB")

                cod_opts = ["-max_band", "NB"]

        else:

            if self.cod_opts:

                cod_opts = self.cod_opts

            else:

                cod_opts = []

        if self.cod_opts:

        cmd.extend(cod_opts)

        cmd.extend(