I was very familiar with Fraunhofer, since they are renowned for their MP3 encoder and in fact helped pioneer MP3 technology. A German company, Fraunhofer continues to do research to come up with the best sounding audio at the lowest bitrates and smallest file size. As we know, Voice over IP (VoIP) also requires high sound quality at the lowest bitrates and smallest file size. In addition, VoIP has low latency requirements, so suppose a codec exists that compresses audio 30% better than any other codec but adds 100ms latency - it would be useless due to unacceptable delay.

So I was fascinated to learn from Fraunhofer about their AAC-ELD codec library, which they call Full-HD Voice, which is one better than HD voice (G.722) we hear so much about. AAC-ELD enables Android 4.1 and iOS 4+ to offer Full-HD Voice, which covers the entire audible spectrum that humans can hear (up to 20 kHz). Full-HD Voice goes above and beyond HD Voice (offering only 7kHz), which mobile operators just beginning to roll out in devices. Major audio codecs (AAC-ELD for speech and HE-AAC for streaming and broadcast) are now native to Android 4.1 and iOS since version 4.0 through the Fraunhofer FDK Codec Library. App developers can now create Full-HD Voice VoIP apps using this codec.

“From mobile phones to TVs, consumers expect the highest audio quality from their entertainment experiences. There is no reason the expectations for VoIP communication should be any different,” said Harald Popp, head of the Multimedia Realtime Systems department at Fraunhofer IIS. “By providing developers direct, native access to the best codecs to deliver Full-HD Voice VoIP apps, consumers can expect the best quality possible.”

Currently, there aren't any VoIP apps that use this codec specifically and then the question of course is will competing codecs like Microsoft/Skype's SILK or the hybrid codec Opus submitted to the IETF render Fraunhofer's codec redundant? Well, SILK uses 8, 12, 16 or 24 kHz and a bit rate from 6 to 40 kbit/s and a low algorithmic delay of 25 ms. AAC-ELD on the other hand supports 24, 36, 48, 64, and 96 kbit/s. Fraunhofer's AAC-ELD codec goes down to 15 ms at 64 kbit/s, and up to 32 ms at 24 kbit/s so it beats SILK in mitigating latency at the higher bitrate. It'll be interesting to see if one of the early pioneers of mp3 music can make it big in VoIP. My 1000+ mp3 collection is certainly grounds to root for these guys to succeed!