MPEG-4 SLS – Lossless and Near-Lossless Audio Coding Based on MPEG-4 AAC

MPEG-4 Scalable Lossless Coding (SLS) is one of the latest extensions to the MPEG-4 audio coding standard. It provides a scalable lossless extension of the well-known MPEG4 AAC codec. The lossless enhancement is performed in a finegrain scalable way, starting from the AAC core signal in small steps all the way up to a numerically lossless representation, thus also including near-lossless compression scenarios. This enables scalable high definition coding of audio signals. The paper provides a brief introduction to the technology of MPEG-4 SLS. In particular, the near-lossless coding capability is examined in detail, and its effectiveness is evaluated in a tandem coding scenario.