new_contents: # -*- coding: utf-8 -*-
  """
      ffmpegwrapper.parameters
      ~~~~~~~~~~~~~~~~~~~~~
  
      Implements a basic structure for commandline
      arguments and some helpers to operate with them.
  
      :copyright: (c) 2012 by Mathias Koehler.
      :license: BSD, see LICENSE for more details.
  """
  from itertools import chain
  from collections import MutableSequence, namedtuple
  
  try:
      from itertools import ifilter
  except ImportError:
      ifilter = filter
  
  
  def format_parameter(*args, **kwargs):
      """Format a parameter string
  
      >>> format_parameter(ex=['example', 'one'])
      '"ex=example:one"'
      >>> format_parameter('one', 'two', 'three')
      'one:two:three'
  
      You can mix the arguments und keyword arguments.
      """
      parameter_list = []
      for value in args:
          if value is not None:
              parameter_list.append(str(value))
      for key, value in kwargs.items():
          try:
              if not value:
                  parameter_list.append(key)
              else:
                  parameter_list.append("=".join([key, value]))
          except TypeError:
              values = ':'.join(kwargs[key])
              parameter_list.append("=".join([key, values]))
      result = ':'.join(parameter_list)
      if kwargs:
          return '"%s"' % result
      return result
  
  
  Parameter = namedtuple('Parameter', ['name', 'value'])
  
  
  class ParameterContainer(MutableSequence):
  
      def __init__(self, *containers):
          self.container_list = list(containers)
  
      def add_parameter(self, key, value):
          """Adds an parameter to the container."""
          self.container_list.append(Parameter(key, value))
  
      def add_formatparam(self, name, *args, **kwargs):
          """Format the value of an parameter from the *args **kwargs
          and append it to the container."""
          parameter = format_parameter(*args, **kwargs)
          self.add_parameter(name, parameter)
  
      def insert(self, index, value):
          self.container_list.insert(index, value)
  
      def iteritems(self):
          return iter(self.container_list)
  
      def __iter__(self):
          return ifilter(None, chain.from_iterable(self.container_list))
  
      def __len__(self):
          return self.container_list.__len__()
  
      def __setitem__(self, index, value):
          self.container_list.__setitem__(index, value)
  
      def __getitem__(self, index):
          return self.container_list.__getitem__(index)
  
      def __delitem__(self, index):
          self.container_list.__delitem__(index)
  
      def __contains__(self, other):
          return self.container_list.__contains__(other)
  
      def __repr__(self):
          return "<{cls} {opts}>".format(
              opts=list(self), cls=self.__class__.__name__)
  
subject: Add missing parameters.py file