Earlier this month, Google announced the general availability of Android 9 “Pie”, along with the first devices incorporating the latest release of Google’s mobile operating system. Android Pie comes with a string of major upgrades in terms of audio playback, since the Extended High-Efficiency AAC (xHE-AAC) audio codec and MPEG-D DRC Loudness and Dynamic Range metadata, both substantially developed by Fraunhofer IIS, are mandatory components of the operating system. The xHE-AAC implementation used by default in Android Pie has been provided by Fraunhofer IIS and is available as part of the FDK2 AAC Codec Library for Android.
Service providers and app developers that want to use xHE-AAC to distribute content can contact Fraunhofer to get access to professional xHE-AAC encoder software or work with one of our streaming equipment partners, such as Modulation Index or Telos. A technical white paper on xHE-AAC and MPEG-D DRC explaining the major use cases, benefits and engineering details is available here. At IBC in Amsterdam, Fraunhofer will demonstrate xHE-AAC and MPEG-D DRC natively on Android Pie phones and in Apple TV streaming apps. Further details are available here.
xHE-AAC is the latest addition to the MPEG AAC audio codec family, extending the usable stereo bit rate range of the codec – as well as the DASH/HLS bit rate range – from 12 kbit/s (stereo) to 500 kbit/s or above. xHE-AAC, which was inherently designed for adaptive streaming, is the only codec that seamlessly switches through the entire bit rate range and quality levels, and reduces audio bit rate requirements by 50% compared to its predecessor HE-AAC. The audio bandwidth saved can then be used in order to improve video quality.
The advanced features of xHE-AAC enable video and audio streaming providers worldwide to offer an enhanced, more reliable consumer experience. The codec can deliver transparent quality for customers on a good network connection and can also seamlessly shift to the bit rates supported by a congested network while on the go. This is particularly of interest to streaming providers active in emerging markets where consumers still rely on 2G or 3G connections.
In addition, MPEG-D DRC – Loudness and Dynamic Range Control – provides mandatory loudness control for xHE-AAC to play back content at a consistent volume and offers dynamic range control processing to provide the best possible user experience for listening on any platform and in any environment.
xHE-AAC and MPEG-D DRC are included in the AAC patent licensing program administered by VIA Licensing at no additional cost.
More information on xHE-AAC in Android Pie is available here.