Structure type generated from the specification.
A description of a codec. 
 
 This should be set to true in calls to   CallContentMediaDescriptionInterface::Accept()  and
   UpdateLocalMediaDescription()  if this
 codec has changed in a way that needs to be signalled over the
 network. If it is set to false, the CM is allowed ignore any
 differences between the current parameters and the previous ones
 
   This mechanism may be used to save bandwidth and avoid the CM
   having to calculate diffs against previous versions of this
   struct, which can lead to false-positives (e.g. redundant ptime
   updates).