Tele- and video conferencing systems for modern business communication are managed by central hubs, so-called multipoint control units (MCU). One major task of these units is the mixing of audio streams from the participating sites. This is traditionally done by decoding the streams, mixing in time domain and then re-encoding of the mixed signals. This requires additional processing power, leads to increased delay and degraded audio quality. The paper demonstrates how the recently standardized MPEG-4 Enhanced Low Delay AAC (AAC-ELD) codec offers a solution to these problems by efficient and delayless mixing in the transform domain of the codec.

Authors: Albert, Tobias; Ekstrand, Per; Geiger, Ralf; Henn, Fredrik; Lutzky, Manfred; Przioda, Daniel; Ruoppila, Vesa; Schmidt, Markus; Schnell, Markus; Tarnes, Erlend
Affiliations: Fraunhofer IIS;Coding Technologies;TANDBERG(See document for exact affiliation information.)
AES Convention: 124 (May 2008) Paper Number: 7337
Publication Date: May 1, 2008 Import into BibTeX
Subject: Low Bit-Rate Audio Coding
Permalink: https://www.aes.org/e-lib/browse.cfm?elib=14467

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