AAC Plus, also known as HE-AAC is the audio codec defined by ISO MPEG4 Audio profile in ISO/IEC 14496-3. HE AAC v1 is defined by the standard ISO/IEC 14496-3:2001/Amd 1:2003. HE AAC v2 is defined by the standard ISO/IEC 14496-3:2005/Amd 2:2006. It is an enhancement of the Advanced Audio Coding (AAC) Low Complexity (LC) profile to achieve better coding quality at lower bit rates. AAC Plus v1 uses Spectral band replication (SBR) to enhance the compression. AAC Plus v2 combines SBR and parametric stereo (PS) to further enhance the compression for stereo streams.
Salient Features
  • Fully Complaint with ISO/IEC 14496-3, ISO/IEC 14496-3:2001/Amd 1:2003 and ISO/ IEC 14496-3:2005/Amd 2:2006
  • Supports stereo and multichannel up to 7.1 channels
  • Supports coupling channels
  • Sampling rates: 8 to 96 khz
  • Bit rates: Supports all the bit rate as per ISO/IEC 14496-3
  • Built in Error handling to take care of corrupted bit-streams. Tested for various types of corrupted bit-streams.
  • Low Mhz and memory foot print
  • Supports raw, adts and adif file formats
  • Re-sync support for fast forward/rewind (with ADTS header)
  • Multi instance and re-entrant implementation
  • Simple API interface
  • Portable audio players
  • Streaming
  • Mobile phones
  • Gaming consoles
  • Broadcast audio
  • ARM
    • ARM9E, ARM11, Cortex A8
  • MIPS
    • MIPS 74kf
    • Base core, DSP and FPU version available
  • TI
    • TMS320C67x, TMS320C66x

Case studies

Developing an Asynchronous Sample Rate Converter

Designing an Asynchronous Sample Rate converter that offers high THD and low ripple across a range of frequencies is no mean achievement. We not only designed the ASRC but implemented it with low MHz on a fixed point processor.

Video codecs on a multi-core highly-parallel custom core

We worked with SiliconHive (now part of Intel) to develop High Definition video codecs that are designed to run optimally on a multi-core environment. Our contribution also included efficient coding for a VLIW core and algorithmic innovations to address memory bandwidth constraints.


Android Auto projection on Telechip TCC8930 running WinCE 7.0
RACE Media & Connectivity IVI suite