*** Welcome to piglix ***

HE-AAC

High-Efficiency Advanced Audio Coding
Filename extension

MPEG/3GPP container

Apple container

  • .m4a, .m4b, .m4p, .m4r, .m4v

Raw stream

  • .aac
Internet media type audio/aacp, audio/3gpp, audio/3gpp2, audio/mp4
Developed by ISO
Type of format Audio compression format
Contained by MPEG-4 Part 14, 3GP and 3G2, ISO base media file format, Audio Data Interchange Format (ADIF), Audio Data Transport Stream (ADTS)
Extended from AAC
Standard ISO/IEC 14496-3

MPEG/3GPP container

Apple container

Raw stream

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.

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.


...
Wikipedia

...