How is the performance of MPEG Audio with respect to cascading, i.e. multiple coding?
This functionality was tested by the International Telecommunication Union (ITU-R). They tested various configurations of repeated encoder/decoder chains at different bitrates with a variety of audio coding algorithms. MPEG Audio performed best in this test. On the basis of these tests, ITU-R recommends the use of MPEG Audio Layer II for contribution (i.e. link between broadcasting studios with provisions for post processing), for distribution (i.e. link between the broadcasting and transmitter station) and for emission (i.e. final transmission between transmitter and receiver at home). The use of MPEG Audio Layer III is recommended for commentary links, i.e. a link for speech signals which are transmitted to the broadcasting station using e.g. one B-channel of an ISDN line.
