Low Latency High-Definition Audio Codec (LHDC) is an
audio codec technology developed by Savitech. LHDC allows
high-resolution audio
High-resolution audio is a term for music files with bit depth greater than 16-bit and sampling frequency higher than 44.1 kHz or 48 kHz used in CD and DVD formats. The Audio Engineering Society (AES), Consumer Technology Association ( ...
streaming over
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is li ...
. It is a high-quality Bluetooth codec based on the A2DP Bluetooth protocol and allows a bit-rate of up to 1000 kbps compared to SBC's bit rate of 345 kbps.
LHDC is an alternative to
Bluetooth SIG's
SBC and
LC3 codecs. Its main competitors are Qualcomm's
aptX-HD/
aptX Adaptive, Huawei
's L2HC and Sony's
LDAC codec.
Starting from
Android 10, enumeration constant symbols for LHDC and LLAC are part of the
Android Open Source Project, enabling every OEM to integrate this standard into their own Android devices freely. Older versions of Android require LHDC/LLAC enumeration constant symbols to be implemented by the smartphone manufacturers or Android app. Android apps with this type of LHDC support include Savitech's Hi-Res BT Player, FiiO Music, HIFIMAN Music and DA&T Audio.
LHDC
LHDC supports bitrates of 160kbps~1000kbps, bit-depth of up to 24 bit and
sample rate
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples".
A sample is a value of the signal at a point in time and/or ...
of up to 192 kHz.
The first
Smartphone
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...
to support LHDC was the
Huawei Mate 10.
On 17 September 2019, the
Japan Audio Society (JAS) certified LHDC with their
Hi-Res Audio Wireless certification. As of June 2024, the codecs certified by the JAS to bear the Hi-Res Audio Wireless logo are LHDC,
LDAC,
SCL6,
LC3plus, SHDC, and
aptX Adaptive.
LLAC
Low Latency Audio Codec (LLAC) is also called LHDC LL. It is based on the high definition wireless audio technology from LHDC, but designed for low latency and features an auto-detect gaming mode. Savitech claims LLAC has end-to-end latency of around ~30ms. LLAC supports bitrates of 400/600 kbit/s, bit-depth of up to 24 bit and
sample rate
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples".
A sample is a value of the signal at a point in time and/or ...
of up to 48 kHz. LLAC has no hardware requirement for the transmitter.
The first
Smartphone
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...
to support LLAC was the
Huawei P30.
Hi-Res Wireless Audio (HWA) Union
On 2 September 2018 the Hi-Res Wireless Audio (HWA) Union was formed to promote LHDC adoption. Also known as the HWA Alliance. The HWA Union Board of Directors includes:
*
AKM
* China Electronics Technology Group Corporation
*
Cirrus Logic
*
Edifier
* Guoguang Electric
*
HiFiMAN
* HiVi
*
Huawei
Huawei Technologies Co., Ltd. ("Huawei" sometimes stylized as "HUAWEI"; ; zh, c=华为, p= ) is a Chinese multinational corporationtechnology company in Longgang, Shenzhen, Longgang, Shenzhen, Guangdong. Its main product lines include teleco ...
* Institute of Acoustics of the Chinese Academy of Sciences
* Savitech
* iriver
*
Sennheiser
* Taihe Music Group
Other HWA Union members include:
*
ams AG
*
Astell & Kern
*
Audio-Technica
* Aukey
* Cayin
* Cozoy
* Coolhere
* Colorfly
* DA&T
* DA-ART
* DUNU
*
FiiO
*
Fostex
* Haylou
* HiBy
* infly
* iEAST
* Liesheng
* Musiland
* NFJ FX-AUDIO
* OC Studio
*
Onkyo
*
Pioneer
* ProStereo
* QCY
* Questyle Audio
* Quloos (QLS HiFi)
* Radius
* Shanling
* S.M.S.L
*
TASCAM
*
TEAC
() is a Japanese electronics manufacturer. TEAC was created by the merger of the Tokyo Television Acoustic Company, founded in 1953, and the Tokyo Electro-Acoustic Company, founded in 1956.
Overview
TEAC has four divisions:
*TASCAM - con ...
* TempoTec
*
Tecsun
* TiinLab
* Topping
* Tube Fan Audio
* VMN
* xDuoo
* YULONG Audio
* 1MORE
HWA Certification
On March 27, 2018, Huawei and Savitech announced the Hi-Res Wireless Audio (HWA) Certification. Platinum HWA Certification requires frequency response over 40 kHz, THD+N<-90 dB, SNR>110 dB, and playback of at least 24bit/96 kHz. Gold HWA Certification requires frequency response over 20 kHz, THD+N<-80 dB, SNR>100 dB, and playback using the at least 24bit/48 kHz.
See also
*
List of codecs
The following is a list of compression formats and related codecs.
Audio compression formats
Non-compression
* Linear pulse-code modulation (LPCM, generally only described as PCM) is the format for uncompressed audio in media files and it is ...
*
Lossy data compression
References
External links
* {{official website
Audio codecs