LC3 (codec)

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] Mono only LC3-SBW is also supported over Bluetooth Classic HFP 1.9, improving on mSBC. It is possible to send 4 LC3 streams to LE audio earbuds, like Samsung's Buds2 Pro.

LC3

Type of format	Audio
Extended to	LC3plus
Standard	Bluetooth 5.2 LE

LC3plus

Type of format	Audio
Standard	ETSI TS 103 634

Codec

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:

• Android 13;^[6][7][8][9] Google's liblc3 codec is open-source as a standalone GitHub project^[10]
• Windows 11, assuming supported Intel CPU and Intel Wifi/bluetooth adapter, on some firmware needs to be released to enable^[11][12]
• Zephyr OS^[13]
• Linux via bluez-alsa^[14] or BlueZ + PipeWire^[15]

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 SCL6 (formerly known as 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

• AptX