MPEG-4. Is a successor to MP3. The very high popularity of MP3 and its incorporation into a large number of players, including CD and DVD players should, however, ensure MP3 longevity for years to come.
Peoplemeter measurement that registers viewer presence by means of remote control push-button handsets, where panel members are instructed to press at the beginning and end of each viewing session. Each person (family member) belonging to the panel is assigned their own button for purposes of individual identification, whilst additional buttons on the remote control handset are reserved for recording guest viewing. Today, all peoplemeter panels collecting audience data for TV advertising and programme purposes employ active measurement.