The Hi-Res Audio Wireless logo issued by the Japan Audio Society (JAS) is an internationally recognized seal of quality. Products that receive the certification meet strict technical requirements. They guarantee that sound is reproduced as accurately as possible, even when listening over a wireless connection like Bluetooth. Only devices that rely on suitable codecs ensuring the exact transport of audio meet the demanding standards of the High-Resolution Audio Wireless logo. This makes it a certificate highly valued by wireless headphone and loudspeaker manufacturers as well as by discerning users.
The LC3plus codec was developed as an open standard and is published as ETSI TS 103 634. It features a dedicated High-Resolution mode, which provides best-in-class Signal to Noise Ratio (SNR) and Total Harmonic Distortion plus Noise (THD+N) performance. The codec operates in its sweet spot between 125 and 250 kbps per channel while allowing seamless bitrate adaptation up to 500 kbps per channel. Other solutions require at least twice the bitrate of LC3plus High-Resolution to achieve a similar performance. This does not only mean a noticeably lower energy consumption, but also that LC3plus makes products very robust and less prone to errors that can occur in wireless environments. In environments with a high density of Bluetooth devices (e.g. in a crowded subway), the codec can be operated in a fallback mode at bitrates down to 64 kbps per channel while maintaining very high audio quality. The reduced bitrate makes packet losses less likely, which ensures an uninterrupted connection.
Implementing LC3plus High-Resolution as the codec of choice for wireless transmission opens the door for device manufacturers to receiving the valuable logo from the Japan Audio Society. The Fraunhofer IIS technology combines best-in-class performance at extremely low energy consumption with the benefits of an open audio standard.
"We are happy that LC3plus is certified for the Hi-Res Audio Wireless logo by the Japanese Audio Society," says Manfred Lutzky, Head of Audio for Communications at Fraunhofer IIS. "True Wireless stereo headphones, which can now receive the Hi-Res Audio Wireless logo, are perfectly adapted for use in Bluetooth LE Audio thanks to the low bit rates of LC3plus."
The LC3 specification has been adopted by Bluetooth SIG and LC3 has been selected as the new default codec for Bluetooth Low Energy (LE) Audio. LC3 is robust enough to improve the overall audio quality perception with wireless Bluetooth devices, and will make it possible for everyone to finally enjoy EVS speech quality in VoLTE calls also via Bluetooth headsets. In parallel, integration work into the legacy Hands-Free Profile has started.
LC3plus is LC3's sibling, equipped with numerous additional functionalities. While comprising all features of LC3, including high speech and audio quality, LC3plus incorporates functionalities for transmission robustness, extremely low-delay use cases and high-resolution audio transmission. To improve robustness, LC3plus contains a very high-performance packet loss concealment algorithm as well as forward error correction schemes such as channel coding or redundancy frame modes.
Furthermore, the LC3plus codec can operate at several low-delay modes – down to 5ms at a 2.5ms packet size, instead of the 7.5 ms frame length mode known from LC3. LC3plus also includes dedicated high-resolution audio modes, which improve the measurable audio quality to provide perceptual transparency (up to 500 kbit/s per channel).
LC3plus’s dedicated high-resolution audio mode provides a high-quality transmission link of 24-bit and 96kHz audio data, which performs excellently with regards to Signal-to-Noise Ratio (SNR) and Total Harmonic Distortion and Noise (THD+N). This makes it the ideal codec to bring high-transparency audio streaming to high-resolution wireless accessories such as headsets or loudspeakers. LC3plus is the only open-standard audio codec for high-resolution wireless headsets and high-quality gaming headsets.
LC3 software for Bluetooth is available through Fraunhofer and additionally, Fraunhofer IIS offers software and licenses for Advanced Packet Loss Concealment as an add-on to the Bluetooth-standardized LC3. Fraunhofer IIS can also provide support with the implementation of LC3plus (and specifically LC3plus HR) in devices based on the Bluetooth A2DP profile. On the Fraunhofer IIS website, the specification is available for use as vendor specific codec via Bluetooth A2DP and upon request, Fraunhofer offers Android patches for LC3plus HR via Bluetooth A2DP.
www.jas-audio.or.jp
www.iis.fraunhofer.de
