| LHDC (codec) | |
|---|---|
 | |
| Developed by | Savitech |
| Type of format | Audio codec |
| Website | www |
Low Latency High-Definition Audio Codec (LHDC) is anaudio codec technology developed by Savitech. LHDC allowshigh-resolution audio streaming overBluetooth. 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.[1]
LHDC is an alternative toBluetooth SIG'sSBC andLC3 codecs. Its main competitors are Qualcomm'saptX-HD/aptX Adaptive, Huawei 's L2HC and Sony'sLDAC codec.
Starting fromAndroid 10, enumeration constant symbols for LHDC and LLAC are part of theAndroid Open Source Project, enabling every OEM to integrate this standard into their own Android devices freely.[2][3] 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 supports bitrates of 160kbps~1000kbps, bit-depth of up to 24 bit andsample rate of up to 192 kHz.[1]
The firstSmartphone to support LHDC was theHuawei Mate 10.[4]
On 17 September 2019, theJapan Audio Society (JAS) certified LHDC with theirHi-Res Audio Wireless certification.[5] As of June 2024, the codecs certified by the JAS to bear the Hi-Res Audio Wireless logo are LHDC,LDAC,SCL6,LC3plus, SHDC, andaptX Adaptive.[6]
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 andsample rate of up to 48 kHz. LLAC has no hardware requirement for the transmitter.[7]
The firstSmartphone to support LLAC was theHuawei P30.[8]
On 2 September 2018 the Hi-Res Wireless Audio (HWA) Union was formed to promote LHDC adoption.[9] Also known as the HWA Alliance. The HWA Union Board of Directors includes:
Other HWA Union members include:
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 of at least 24bit/48 kHz.[10]
