1、QUESTION ITU-R 19-1/6 Bit-rate reduction coding of audio signals for broadcasting applications (1993-1995-2002-2009) The ITU Radiocommunication Assembly, considering a) that a number of different bit-rate reduction coding systems have been developed for digital audio applications; b) that requiremen
2、ts on bit-rate reduction coding systems for broadcasting are specified in Recommendations ITU-R BS.1548; c) that recent progress in digital audio coding techniques allows for a very considerable degree of bit-rate reduction to be achieved while maintaining high quality; d) that applications exist fo
3、r audio bit-rate reduction coding systems for digital audio broadcasting, television sound and for storage of signals; e) that the requirements for the various broadcasting applications mentioned in c) might be very different and should be carefully defined in view of the planned services; f) that t
4、he performance of the whole broadcasting chain should be considered, and multiple transcoding between bit-rate reduction coding standards used for production, transmission links and broadcasting should be avoided as far as possible, decides that the following Questions should be studied 1 What are t
5、he sound quality and other requirements needed for production including recording, for transmission links and for various broadcasting applications from terrestrial transmitters and for satellite, including multichannel audio formats? 2 What are the bit-rate reduction techniques that would satisfy t
6、he quality level and other requirements for each of the applications listed in 1 while making efficient use of storage or transmission media? 3 What are the techniques which would maximize interoperability between the various parts of the broadcasting chain? 4 What is the nature of signal impairment
7、s due to bit-rate reduction coding techniques, in particular after a number of cascaded codecs? 5 What are the lossless bit-rate reduction techniques which could be applied to audio coding, especially for studio and storage application? 6 What methods could be used to minimize the incompatibilities
8、between the various bit-rate reduction coding techniques and what interface for compressed bit-rate audio can be recommended to avoid transcoding digital signals in linear format? 7 What methods of transcoding between low bit-rate coding techniques adopted by ITU-R can be recommended, if unavoidable
9、? 8 What audio coding schemes are appropriate for application where remote interaction is important? further decides 1 that the results of the above studies should be included in (a) Report(s) and/or Recommendation(s); 2 that the above studies should be completed by 2011. Category: S2 Formatted: Font: Bold
