AAC File Documentation

Overview

Feature Value
File Extension .aac
MIME Type audio/aac
Compression Type Lossy
Developed by Bell Labs, Fraunhofer Institute, Dolby Laboratories, Sony Corporation and Nokia
First Introduced 1997
Part of MPEG-2 and MPEG-4 specifications
Audio Channels Supports up to 48 channels
Sample Rate From 8 kHz to 96 kHz
Bit Rate Variable, up to 576 kbps for single channel
Efficiency More efficient than MP3
Audio Quality High, even at low bit rates
Supports Metadata Yes
Usage Streaming and broadcasting, digital radio, TV, and file distribution
Compatibility Wide range of devices and software
Encoding Methods Main, LC (Low Complexity), SSR (Scalable Sample Rate), LTP (Long Term Prediction)
Copy Protection Possible with DRM
Surround Sound Supported
Frequency Cut-off Variable depending on compression
Advantages over MP3 Better sound quality at lower bit rates, more efficient compression
Audio Object Coding Supported with MPEG-4 SLS, MPEG-4 ALS and MPEG-D USAC