The audio codec of choice for digital radio and low bit rate Audio and Video streaming applications


xHE-AAC (Extended HE-AAC), the latest upgrade to the MPEG AAC codec family, is the audio codec of choice for digital radio and low bit rate streaming applications. Selected as the mandatory audio codec for DRM (Digital Radio Mondiale), xHE-AAC bridges the gap between speech and audio coding, and provides consistent high quality audio for all signal types, such as speech, music or mixed content.

Another important feature is the codec’s coding efficiency. The audio codec produces excellent sound for both music and speech, delivering high quality performance at bit rates starting as low as 6 kbit/s for mono and 12 kbit/s for stereo services. Thus xHE-AAC streaming apps and streaming radio players may switch to very low bit rate streams and offer a continuous playback even while the network is congested. Once more bandwidth becomes available on the network again, the xHE-AAC client can request a higher bit rate version and seamlessly switch over the full range of bit rates. Audio bit rate that’s being saved due to the improved coding efficiency can be used to improve video quality.

xHE-AAC is an upgrade of HE-AAC v2 with integrated speech coding tools and more efficient tools for general audio signal coding.
© Fraunhofer IIS

xHE-AAC is an upgrade of HE-AAC v2 with integrated speech coding tools and more efficient tools for general audio signal coding.

Composition and compatibility of xHE-AAC

xHE-AAC profile decoders are capable of decoding all AAC versions including AAC-LC, HE-AAC and HE-AACv2. xHE-AAC streams can easily be integrated into existing encoding workflows by supplementing legacy higher bit rate streams.


With its special features, xHE-AAC effortlessly meets the requirements of digital radio and mobile audio and video streaming applications where various audio content types need to be transmitted at very low bit rates.

xHE-AAC for streaming applications

It opens up the possibility to reach billions of 2G users with streaming services for the first time especially in emerging markets such as India. Streaming service providers benefit from drastically reduced CDN cost and a simplified encoding asset management, while consumers enjoy an improved service quality while saving on their precious monthly data allowance.


DRM (Digital Radio Mondiale) is the first digital radio standard to adopt xHE-AAC and therefore benefiting from its features.

DRM is a typical application scenario for xHE-AAC. The digital radio standard adopted it as mandatory audio codec in 2013. xHE-AAC is a superset of the MPEG HE‑AAC codec used for all DRM transmissions to date. Of course, HE‑AAC remains available as part of the DRM standard to retain compatibility with existing systems. DRM broadcasters benefit from a simplified codec configuration process: All quality relevant parameters are automatically optimized internally by the encoder, and the need to change configuration settings depending on the type of audio content being broadcast is eliminated.


Codec implementations of xHE-AAC for use in DRM and streaming applications are available for the following hardware platforms:

  • PC (Windows/Mac OS X/Linux)
  • ARM (decoder only)
  • MIPS (decoder only)
  • Texas Instruments C6x, DaVinci, OMAP (decoder only)
  • Analog Devices Blackfin (decoder only)
  • Apple iOS® SDK (decoder only)
  • Android™

DRM broadcast encoder solutions based on Fraunhofer’s ContentServer technology, as well as third-party implementations, already support xHE-AAC. All DRM receiver chipsets belonging to the initial mass-market generation include xHE-AAC from market launch.

Further information about our development and design kits can be found on our "platforms" page.


If you are interested in licensing software from us please fill out the request form below.

Patent licensing:

xHE-AAC is part of the AAC patent pool licensing program administered by Via Licensing Corporation. Please visit www.vialicensing.com for more information or contact info@vialicensing.com.

The corresponding news release can be found here: http://www.via-corp.com/newsdetail.aspx?id=2372.


Audio and Media Technologies at IBC2016

We always look forward to coming to Amsterdam for the IBC exhibition: It’s the perfect place to meet up with professionals of multimedia content creation and distribution, and to present our latest Audio & Media technologies.

xHE-AAC is one of these technologies – tune in to learn more about the audio codec and our other exhibits for digital radio, streaming, TV broadcast or Virtual Reality, and see how they all can form the future.

Fraunhofer Prize 2016: Digital Radio for the World

Digital radio makes spherics and crackling interference in radio broadcast a thing of the past. New technologies from Fraunhofer IIS make it possible for digital radio to replace analogue short and medium wave broadcasting around the world. Alexander Zink, Martin Speitel, Max Neuendorf and their entire development team received the Fraunhofer Prizes 2016 as recognition of their efforts in developing the foundations of digital radio and its continuation to market roll-out.

Request licensing information: xHE-AAC

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