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Implementation of AAC Encoder for Audio Broadcasting

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MP3 is the popular audio coding standard. But now, a new higher quality audio coding standard Advanced Audio Coding (AAC) is proposed and widely used. The quantization/re-quantization is essential in both MP3 and AAC. It proposes a new high accuracy estimation algorithm for MP3 and MEPG-4 AAC audio coding. The algorithm can be applied not only for re-quantization process in decoder, but also for quantization in encoder. The implementation of the multichannel AAC encoder system for digital audio Broadcasting. The encoder system is based on MPEG-2/4 Advanced Audio Coding (AAC) and capable of real time encoding up to 5.1 channel audio. To give a flexible functionality, it consists of multiple DSPs, IEC61937 and TCPIIP interface and 6 channel audio input facilities. The reference AAC decoder was implemented for verification test of the encoder. The encoder system also integrated with AAC streaming system for interoperation test. Through these tests, the encoder system was verified to be a good solution for high quality audio broadcasting.
Keywords: Audio Codec, Bit-rate, Filter Bank, MPEG-4,MP3.


  1. A.M. Kondoz, “Digital Speech: Coding for Low Bit Rate Communication Systems”, 2nd Ed., Wiley, 2004.
  2. R. Yu, T. Li, and S. Rahardja: “Sound Analysis using MPEG Compressed Audio,” Proceedings of IEEE International Conference Acoustic, Speech, and Signal Processing (ICASSP2000), pp. 761–764, 2005.
  3. Matthew A.Watson and Peter Buettner,“Design and implementation of AAC decoders,”IEEE Transactions on Consumer Electronics, Vol. 46, Issue:3, pp.819-824, Aug. 2000.
  4. Purnhagen H. and Meine N., “HILN-The MPEG-4 Parametric Audio Coding Tools”, Proc. IEEE ISCAS 2001, pp.201-204. May 2001.
  5. P. Srinivasan and L. H. Jamieson, "High-Quality Audio Compression Using an Adaptive Wavelet Packet Decomposition and Psychoacoustic Modeling," IEEE Trans. on Signal Processing, vol. 46, no. 4, pp. 1085-1093, April 2008.
  6. J. Li. Embedded audio coding (EAC) with implicit psychoacoustic masking. ACM Multimedia 2002, pages 592–601, December 2002.
  7. G. Tzanetak and P. Cook: is Perceptually enhanced bit-plane coding for scalable audio. Int. Conf. Multimedia & Expo (ICME), (July):1153–1156, 2006.