![]() Testing indicates that material decoded from 64 kbit/s HE-AAC does not quite have similar audio quality to material decoded from MP3 at 128 kbit/s using high quality encoders. , ISO/IEC 14496-3:2001/Amd.1:2003 andĪt the time, Coding Technologies had already begun using the trade names AAC+ and aacPlus for what is now known as HE-AAC v1, and aacPlus v2 and eAAC+ for what is now known as HE-AAC v2. Parts of the HE-AAC specification had previously been standardized and published by various bodies in HE-AAC v1 was standardized as a profile of MPEG-4 Audio in 2003 by MPEG and published as part of the ISO/IEC 14496-3:2001/Amd 1:2003 specification. Subsequently, Coding Technologies submitted their SBR mechanism to MPEG as a basis of what ultimately became HE-AAC. The progenitor of HE-AAC was developed by Coding Technologies by combining MPEG-2 AAC-LC with a proprietary mechanism for spectral band replication (SBR), to be used by XM Radio for their satellite radio service. HE-AAC is used in digital radio standards like HD Radio, DAB+ and Digital Radio Mondiale. The usage profile HE-AAC v2 couples SBR with Parametric Stereo (PS) to further enhance the compression efficiency of stereo signals. The usage profile HE-AAC v1 uses spectral band replication (SBR) to enhance the modified discrete cosine transform (MDCT) compression efficiency in the frequency domain. ![]() It is an extension of Low Complexity AAC (AAC-LC) optimized for low- bitrate applications such as streaming audio. 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. Evolution from MPEG-2 AAC-LC (Low Complexity) Profile and MPEG-4 AAC-LC Object Type to HE-AAC v2 Profile. Based on the MPEG-4 Part 3 technical specification. Similarly, The HE-AAC v2 decoder can handle all HE-AAC profile streams as well as all AAC profile streams. The HE-AAC profile decoder is fully capable of decoding any AAC profile stream. Hierarchical structure of AAC profile, HE-AAC profile and HE-AAC v2 profile, and compatibility between them. MPEG-4 Part 14, 3GP and 3G2, ISO base media file format, Audio Data Interchange Format (ADIF), Audio Data Transport Stream (ADTS) High-Efficiency Advanced Audio Coding Filename extensions Not to be confused with MPEG-4 SLS, which is branded HD-AAC. ![]()
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