High-Efficiency Advanced Audio Coding

High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/IEC 14496-3. It is an extension of Low Complexity AAC (AAC LC) optimized for low-bitrate applications such as streaming audio. HE-AAC version 1 profile (HE-AAC v1) uses spectral band replication (SBR) to enhance the compression efficiency in the frequency domain. HE-AAC version 2 profile (HE-AAC v2) couples SBR with Parametric Stereo (PS) to enhance the compression efficiency of stereo signals. It is a standardized and improved version of the AACplus codec.

HE-AAC is used in digital radio standards like DAB+ and Digital Radio Mondiale.

History

The progenitor of HE-AAC was developed by Coding Technologies under the trade name CT-aacPlus. CT-aacPlus combined MPEG-2 AAC LC with the Coding Technologies invented spectral band replication (SBR). CT-aacPlus is the codec used by XM Radio for their satellite radio service. Subsequently, Coding Technologies submitted their SBR to MPEG as a basis of HE-AAC.

P5+1

The P5+1 is a group of six world powers which, in 2006, joined together in diplomatic efforts with Iran with regard to its nuclear program. The term refers to the UN Security Council's five permanent members (the P5); namely China, France, Russia, the United Kingdom, and the United States; plus Germany. The P5+1 is often referred to as the E3+3 by European countries. In the same context, E3/EU+3 means the P5+1 plus the High Representative of the European Union (EU) for Foreign Affairs and Security Policy; the text of agreements with Iran uses E3+3 and E3/EU+3, but not P5+1.

History

In June 2006, China, Russia, and the United States joined the three EU-3 countries, which had been negotiating with Iran since 2003, to offer another proposal for comprehensive negotiations with Iran.

Up to then, the UN Security Council has adopted six resolutions in response to the Iranian nuclear program. The first resolution, #1696, was adopted in July 2006 and demands that Iran halt its uranium enrichment-related and reprocessing activities.

AAC

AAC may refer to:

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