LC3 (codec)
| LC3 | |
|---|---|
| Type of format | Audio |
| Extended to | LC3plus |
| Standard | Bluetooth 5.2 LE |
| Free format? | Yes |
| LC3plus | |
|---|---|
| Type of format | Audio |
| Standard | ETSI TS 103 634 |
| Free format? | No |
LC3 (Low Complexity Communication Codec) is a royalty-free audio codec specified by the Bluetooth Special Interest Group (SIG) for the Bluetooth Low Energy (BLE)'s audio protocol and introduced about the time of Bluetooth 5.2.[1] It is developed by Fraunhofer IIS and Ericsson, and succeeds the SBC codec.[2] Mono (single-channelled) LC3-SWB is supported over the Hands-Free Profile (HFP) 1.9, succeeding mSBC. A Bluetooth LE peripheral can receive up to 4 audio streams (e.g., that of 4 different audio channels) simultaneously. Pairs of wireless earbuds often register as a single peripheral device, despite being physically distinct.
Codec
LC3 provides higher audio quality and better packet loss concealment than SBC and G.722, with disputed results against Opus, according to subjective testing done by the Bluetooth SIG and ETSI.[3][4][5] The comparison against Opus is disputed for the test including only speech audio, and using the older 1.1.4 version of the reference Opus encoder, at 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:
- Android 13;[6][7][8][9] Google's liblc3 codec is open-source as a standalone GitHub project[10]
- Windows 11, assuming both hardware (e.g., a wireless network card) and driver support[11][12]
- Zephyr OS[13]
- Linux via bluez-alsa[14], or the combination of BlueZ and PipeWire[15]
LC3plus
LC3plus is defined by ETSI and is not royalty free nor compatible with the standard LC3 codec.[16]: 3 It's included in the 2019 DECT standard,[17] and is source-available.[18] The codec received Hi-Res certification from the Japan Audio Society (JAS) in 2022,[19] alongside the SCL6, LDAC and LHDC.
See also
- List of codecs#Bluetooth for a list of audio codecs designed for Bluetooth
- List of codecs#Audio compression formats for all audio codecs in general
References
- ^ "LE Audio". Bluetooth Technology Website. Retrieved 2020-01-08.
- ^ "LC3 / LC3plus". Fraunhofer IIS. Retrieved 2020-01-10.
- ^ Frumusanu, Andrei. "CES 2020: Bluetooth SIG Announces LE Audio Standard: New Baseline For Next Decade". www.anandtech.com. Archived from the original on January 8, 2020. Retrieved 2020-01-08.
- ^ "New Bluetooth codec improves sound quality, benefits the hearing impaired". Android Authority. 2020-01-07. Retrieved 2020-01-08.
- ^ 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.
- ^ "Android 13 may finally bring full support for Bluetooth LE Audio". xda-developers. 2021-12-22. Retrieved 2022-04-22.
- ^ "Features and APIs Overview - Android 13 Developer Preview". Android Developers. Retrieved 2022-04-22.
- ^ "New LC3 Encoder (I5f2f7627)". AOSP Gerrit. Retrieved 2022-04-22.
- ^ "Add new LC3 decoder (I275ea8ba)". AOSP Gerrit. Retrieved 2022-04-22.
- ^ "google/liblc3: Low Complexity Communication Codec (LC3)". GitHub. 26 June 2023. Retrieved 6 July 2023.
- ^ Roth, Emma (2023-05-23). "Windows 11 adds support for Bluetooth's low-energy audio spec". The Verge. Retrieved 2023-05-25.
- ^ 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.
- ^ "modules: Add zephyr lc3 codec by Casper-Bonde-Bose · Pull Request #44225 · zephyrproject-rtos/zephyr". GitHub. Retrieved 2022-04-24.
- ^ "Bluez-alsa/SRC at master · arkq/Bluez-alsa". GitHub.
- ^ "BlueZ » Blog Archive » LE Audio support in PipeWire".
- ^ LC3plus High Resolution |Specification for use as vendor specific codec via Bluetooth A2DP (PDF), Fraunhofer Institute for Integrated Circuits IIS, 2021
- ^ "LC3 / LC3plus: A plus in audio quality and transmission robustness for wireless accessories". Fraunhofer-Gesellschaft. Retrieved 2022-05-01.
- ^ "marzzzello/LC3plus". GitHub. 29 June 2023.
- ^ ""Hi-Res AUDIO WIRELESS" Two new codecs added to "Hi-Res AUDIO WIRELESS" logo's certified codecs". Retrieved 9 November 2022.