High-Quality and Processor-Efficient Implementation of an MPEG-2 AAC Encoder

Yuichiro TAKAMIZAWA  Toshiyuki NOMURA  Masao IKEKAWA  

Publication
IEICE TRANSACTIONS on Information and Systems   Vol.E86-D   No.3   pp.418-424
Publication Date: 2003/03/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8532
Type of Manuscript: Special Section PAPER (Special Issue on Speech Information Processing)
Category: Speech and Audio Coding
Keyword: 
MPEG-2 AAC,  audio,  encoder,  compression,  SIMD,  

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Summary: 
This paper describes high-quality and processor-efficient software implementation of an MPEG-2 AAC LC Profile encoder. MDCT and quantization processing are accelerated by 21.3% and 19.0%, respectively, through the use of SIMD instructions. In addition, psycho-acoustic analysis in the MDCT domain makes the use of FFTs unnecessary and reduces the computational cost of the analysis by 56.0%. The results of subjective quality tests show that better sound quality is provided by greater efficiency in quantization processing and Huffman coding. All of this results in high-quality and processor-efficient software implementation of an MPEG-2 AAC encoder. Subjective test results show that the sound quality achieved at 96 kb/s/stereo is equivalent to that of MP3 at 128 kb/s/stereo. The encoder works 13 times faster than realtime for stereo encoding on an 800 MHz Pentium III processor.