Bit Reservoir Design for HE AAC
Li-Wei Chen, Han-Wen Hsu, Wen‐Chieh Lee, Chi‐Min Liu · Journal of the Audio Engineering Society · 2005
High Efficiency AAC (HE-AAC) has included the Spectral Band Replication (SBR) in combination with AAC to achieve high audio quality at bit rates lower than 96 kbits per second. SBR reconstructs high frequency signal through replicating the low frequency parts. The bits allocated to AAC encoder module and SBR module decides the quality and compression efficiency. In the past, we have designed the bit reservoir for AAC to reserve and predict the bits necessary for each time frame. The bit reservoir should be extended for HE-AAC especially for the SBR module. This paper considers the design of the bit reservoir for the HE-AAC. The efficiency of bit reservoir is verified through extensive objective tests.