LC3 (Low Complexity Communication Codec) is an audio codec specified by the Bluetooth Special Interest Group (SIG) for the LE Audio audio protocol introduced in Bluetooth 5.2.[1] It's developed by Fraunhofer IIS and Ericsson as the successor of the SBC codec.[2]

LC3 provides higher audio quality and better Packet loss concealment than SBC, G.722 and Opus, according to subjective testing by the Bluetooth Special Interest Group and ETSI.[3][4][5] The conclusion regarding Opus is disputed as the test only included speech audio, but the comparison was made to version 1.1.4 of the reference Opus encoder, using complexity level 0 at 32 kbps and relying on CELT (general audio) instead of the FEC-capable SILK (speech); the test also did not take into account the newer version 1.2 of the Opus encoder released in 2017, where significant improvements were made to low bitrate streams.[5]

Supported systems:

LC3plus

LC3plus High Resolution mode is a codec defined by ETSI and is not compatible with the LC3 defined by Bluetooth SIG.[16]: 3  It's included in the 2019 DECT standard.[17]

On November 9, 2022, the Japan Audio Society (JAS) released a statement certifying LC3plus with the "Hi-Res AUDIO WIRELESS" logo.[18] LC3plus is the 4th codec to receive this, alongside MQair, LDAC and LHDC codecs.

The ETSI implementation of LC3plus is source-available software, subject to a ETSI Intellectual Property Rights Policy and the usual patent restrictions.[19]

Fraunhofer defines a way to use LC3plus over A2DP.

See also

References

  1. ^ "LE Audio". Bluetooth Technology Website. Retrieved 2020-01-08.
  2. ^ "LC3 / LC3plus". Fraunhofer IIS. Retrieved 2020-01-10.
  3. ^ Frumusanu, Andrei. "CES 2020: Bluetooth SIG Announces LE Audio Standard: New Baseline For Next Decade". www.anandtech.com. Retrieved 2020-01-08.
  4. ^ "New Bluetooth codec improves sound quality, benefits the hearing impaired". Android Authority. 2020-01-07. Retrieved 2020-01-08.
  5. ^ a b "Digital Enhanced Cordless Telecommunications (DECT); Study of Super Wideband Codec in DECT for narrowband, wideband and super-wideband audio communication including options of low delay audio connections (≤ 10 ms framing)" (PDF). ETSI. September 2018.
  6. ^ "Android 13 may finally bring full support for Bluetooth LE Audio". xda-developers. 2021-12-22. Retrieved 2022-04-22.
  7. ^ "Features and APIs Overview - Android 13 Developer Preview". Android Developers. Retrieved 2022-04-22.
  8. ^ "New LC3 Encoder (I5f2f7627)". AOSP Gerrit. Retrieved 2022-04-22.
  9. ^ "Add new LC3 decoder (I275ea8ba)". AOSP Gerrit. Retrieved 2022-04-22.
  10. ^ "google/liblc3: Low Complexity Communication Codec (LC3)". GitHub. 26 June 2023. Retrieved 6 July 2023.
  11. ^ Roth, Emma (2023-05-23). "Windows 11 adds support for Bluetooth's low-energy audio spec". The Verge. Retrieved 2023-05-25.
  12. ^ Blog, Windows Experience; Woodman, Aaron (2023-05-23). "Announcing new Windows 11 innovation, with features for secure, efficient IT management and intuitive user experience". Windows Experience Blog. Retrieved 2023-05-25.
  13. ^ "modules: Add zephyr lc3 codec by Casper-Bonde-Bose · Pull Request #44225 · zephyrproject-rtos/zephyr". GitHub. Retrieved 2022-04-24.
  14. ^ "Bluez-alsa/SRC at master · arkq/Bluez-alsa". GitHub.
  15. ^ "BlueZ » Blog Archive » LE Audio support in PipeWire".
  16. ^ LC3plus High Resolution |Specification for use as vendor specific codec via Bluetooth A2DP (PDF), Fraunhofer Institute for Integrated Circuits IIS, 2021
  17. ^ "LC3 / LC3plus: A plus in audio quality and transmission robustness for wireless accessories". Fraunhofer-Gesellschaft. Retrieved 2022-05-01.
  18. ^ ""Hi-Res AUDIO WIRELESS" Two new codecs added to "Hi-Res AUDIO WIRELESS" logo's certified codecs". Retrieved 9 November 2022.
  19. ^ "marzzzello/LC3plus". GitHub. 29 June 2023.