Advanced Audio Coding

Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.

AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications. Part of the AAC known as High Efficiency Advanced Audio Coding (HE-AAC) which is part of MPEG-4 Audio is also adopted into digital radio standards like DAB+ and Digital Radio Mondiale, as well as mobile television standards DVB-H and ATSC-M/H.

AAC supports inclusion of 48 full-bandwidth (up to 96 kHz) audio channels in one stream plus 16 low frequency effects (LFE, limited to 120 Hz) channels, up to 16 "coupling" or dialog channels, and up to 16 data streams. The quality for stereo is satisfactory to modest requirements at 96 kbit/s in joint stereo mode; however, hi-fi transparency demands data rates of at least 128 kbit/s (VBR). The MPEG-2 audio tests showed that AAC meets the requirements referred to as "transparent" for the ITU at 128 kbit/s for stereo, and 320 kbit/s for 5.1 audio.

AAC

AAC may refer to:

Sports

6 Regiment Army Air Corps

6 Regiment Army Air Corps is the sole Army Reserve regiment of the Army Air Corps (AAC). The regiment operates in a groundcrew role, providing support to Army Aviation units of the Joint Helicopter Command.

History

6 Regiment Army Air Corps (6 AAC) was formed on 2 July 2006 at Bury St Edmunds, Suffolk. It is the only reserves regiment of the Army Air Corps. The Regiment was initially formed as an attack helicopter ground crew regiment, providing attack helicopter support to the regular Army Air Corps regiments at Wattisham. The regiment has since begun training groundcrew to work with the Lynx, allowing it to provide general support to the majority of the Army Air Corps.

In 2009 655 Squadron (V) The Scottish Horse joined the regiment.

The Army 2020 and Future Reserves 20 announcements in July 2013 made significant changes to the role and structure of 6 Regiment Army Air Corps. Those changes will be largely in place by 1 April 2014, though extensive conversion training will continue until approximately 2017.