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Abstract
The MPEG2 Advanced Audio Coding (AAC) system gives specifications
on how to compress incoming audio data in the range
of 8kHz to 96kHz in steps. The AAC offers three different
profiles to facilitate tradeoff between quality, memory
and processing power requirements. They include: Main
Profile (MP), Low Complexity (LC) and Scalable Sampling
Rate (SSR) Main Profile (MP): This configuration ensures
best audio quality at any given data rate. All tools
of the ACC except the ihgain control toollo can be used.
Low Complexity (LC) Profile: The quality performance
of the LC profile is very high but compared to the MP
the memory and processing power requirements are considerably
reduced. Prediction and preprocessing tools are not
used and TNS order is limited.
Scalable Sampling Rate (SSR) Profile: The SSR profile
has lower complexity than MP and LC profiles. It can
provide a frequency scalable signal. The SSR requires
the gain control tool. It does not use the prediction
module and the TNS order and bandwidth are limited.
The article further discusses the entire process and
functioning of the instrument.
Authors
Tapas Datta,
Rajita Kaundin
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