LC3 (codec)

Last updated
LC3
Type of formatAudio
Extended toLC3plus
Standard Bluetooth 5.2 LE
LC3plus
Type of formatAudio
Standard ETSI TS 103 634

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]

Contents

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

Related Research Articles

<span class="mw-page-title-main">Digital enhanced cordless telecommunications</span> ITU Standard for cordless telephone systems

Digital Enhanced Cordless Telecommunications (DECT) is a cordless telephony standard maintained by ETSI. It originated in Europe, where it is the common standard, replacing earlier standards, such as CT1 and CT2. Since the DECT-2020 standard, it also includes IoT communication.

Speech coding is an application of data compression to digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic data compression algorithms to represent the resulting modeled parameters in a compact bitstream.

<span class="mw-page-title-main">High-Efficiency Advanced Audio Coding</span> Audio codec

High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/IEC 14496–3. It is an extension of Low Complexity AAC (AAC-LC) optimized for low-bitrate applications such as streaming audio. The usage profile HE-AAC v1 uses spectral band replication (SBR) to enhance the modified discrete cosine transform (MDCT) compression efficiency in the frequency domain. The usage profile HE-AAC v2 couples SBR with Parametric Stereo (PS) to further enhance the compression efficiency of stereo signals.

<span class="mw-page-title-main">Android 13</span> Thirteenth major version of the Android mobile operating system

Android 13 is the thirteenth major release and the 20th version of Android, the mobile operating system developed by the Open Handset Alliance led by Google. It was released to the public and the Android Open Source Project (AOSP) on August 15, 2022. The first devices to ship with Android 13 were the Pixel 7 and 7 Pro.

A Bluetooth stack is software that is an implementation of the Bluetooth protocol stack.

<span class="mw-page-title-main">Audio headset</span> Telephone or computer accessory

A headset is a combination of headphone and microphone. Headsets connect over a telephone or to a computer, allowing the user to speak and listen while keeping both hands free. They are commonly used in customer service and technical support centers, where employees can converse with customers while typing information into a computer. They are also common among computer gamers and let them talk with each other and hear others while using their keyboards and mice to play the game.

Wideband audio, also known as wideband voice or HD voice, is high definition voice quality for telephony audio, contrasted with standard digital telephony "toll quality". It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 100 Hz to 17 kHz but traditional, voiceband or narrowband telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency range of 50 Hz to 7 kHz. In addition, some wideband codecs may use a higher audio bit depth of 16 bits to encode samples, also resulting in much better voice quality.

SBC, or low-complexity subband codec, is an audio subband codec specified by the Bluetooth Special Interest Group (SIG) for the Advanced Audio Distribution Profile (A2DP). SBC is a digital audio encoder and decoder used to transfer data to Bluetooth audio output devices like headphones or loudspeakers. It can also be used on the Internet. It was designed with Bluetooth bandwidth limitations and processing power in mind to obtain a reasonably good audio quality at medium bit rates with low computational complexity. As of A2DP version 1.3, the Low Complexity Subband Coding remains the default codec and its implementation is mandatory for devices supporting that profile, but vendors are free to add their own codecs to match their needs.

Bluetooth Low Energy is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group aimed at novel applications in the healthcare, fitness, beacons, security, and home entertainment industries. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range.

aptX Family of proprietary audio codecs owned by Qualcomm

aptX is a family of proprietary audio codec compression algorithms owned by Qualcomm, with a heavy emphasis on wireless audio applications.

SILK is an audio compression format and audio codec developed by Skype Limited, now a Microsoft subsidiary. It was developed for use in Skype, as a replacement for the SVOPC codec. Since licensing out, it has also been used by others. It has been extended to the Internet standard Opus codec.

<span class="mw-page-title-main">Opus (audio format)</span> Lossy audio coding format

Opus is a lossy audio coding format developed by the Xiph.Org Foundation and standardized by the Internet Engineering Task Force, designed to efficiently code speech and general audio in a single format, while remaining low-latency enough for real-time interactive communication and low-complexity enough for low-end embedded processors. Opus replaces both Vorbis and Speex for new applications, and several blind listening tests have ranked it higher-quality than any other standard audio format at any given bitrate until transparency is reached, including MP3, AAC, and HE-AAC.

Unified Speech and Audio Coding (USAC) is an audio compression format and codec for both music and speech or any mix of speech and audio using very low bit rates between 12 and 64 kbit/s. It was developed by Moving Picture Experts Group (MPEG) and was published as an international standard ISO/IEC 23003-3 and also as an MPEG-4 Audio Object Type in ISO/IEC 14496-3:2009/Amd 3 in 2012.

<span class="mw-page-title-main">Voice over LTE</span> High-speed wireless communication functionality

Voice over LTE (VoLTE) is an LTE high-speed wireless communication standard for voice calls using mobile phones and data terminals. VoLTE has up to three times more voice and data capacity than older 3G UMTS and up to six times more than 2G GSM. It uses less bandwidth because VoLTE's packet headers are smaller than those of unoptimized VoIP/LTE. VoLTE calls are usually charged at the same rate as other calls.

Fraunhofer FDK AAC is an open-source library for encoding and decoding digital audio in the Advanced Audio Coding (AAC) format. Fraunhofer IIS, developed this library for Android 4.1. It supports several Audio Object Types including MPEG-2 and MPEG-4 AAC LC, HE-AAC, HE-AACv2 as well AAC-LD and AAC-ELD for real-time communication. The encoding library supports sample rates up to 96 kHz and up to eight channels.

<span class="mw-page-title-main">LDAC (codec)</span> Digital audio encoding technology

LDAC is a proprietary audio coding technology developed by Sony, which allows streaming high-resolution audio over Bluetooth connections at up to 990 kbps at 32 bits/96 kHz. It is used by various products, including headphones, earphones, smartphones, portable media players, active speakers, and home theaters.

Low Latency High-Definition Audio Codec (LHDC) is an audio codec technology developed by Savitech. LHDC allows high-resolution audio streaming over Bluetooth. It is a high-quality Bluetooth codec based on the A2DP Bluetooth protocol and allows a bit-rate of up to 900 kbit/s compared to SBC's bit rate of 345 kbit/s.

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. 1 2 "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.
Wireless tower.svg

This article about wireless technology is a stub. You can help Wikipedia by expanding it.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.