AES E-Library

Low-Power MPEG-4 HE-AAC Version-2 Encoder

In MPEG-4 HE-AAC version-2 encoder, the analysis/synthesis complex-exponential modulation filter banks are used in spectral band replication (SBR) and parametric stereo (PS) coding. Due to the aliasing interference, the complex banks instead of real banks are adopted in the SBR and PS coding. However, the additional overhead from the complex values in the CEMFB and the subsequent processing have led to high operational overhead. Our previous work has designed the SBR encoders based on the real-domain cosine modulation filter banks; we proposed a complexification-based approach for the SBR coding. This paper extends the work into PS coding. An approximate method for parameters estimation is proposed to save operational overhead with only one CEMFBanalysis channel. Also, a phase-adjustment down-mixing method is proposed to reduce energy vanish effects.

Authors: Hsu, Han-Wen; Lee, Wen-Chieh; Liu, Chi-Min; Yang, Chung-Han
Affiliation: National Chiao Tung University
AES Convention:124 (May 2008) Paper Number:7338 Import into BibTeX
Subject:Low Bit-Rate Audio Coding

Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.

Learn more about the AES E-Library

E-Library Location: (CD 124Papers)   /124/7338.pdf

Start a discussion about this paper!