LHDC (codec)
| Developed by | HWA Union, Savitech |
|---|---|
| Type of format | Audio codec |
Low latency and High-Definition audio Codec (LHDC), also known as HWA, is an audio codec technology developed by the Hi-Res Wireless Audio (HWA) Union and Savitech. LHDC allows high-resolution audio streaming over Bluetooth.[1]
LHDC is an alternative to Bluetooth SIG's SBC and LC3 codecs. Its main competitors are Qualcomm's aptX-HD/aptX Adaptive 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.[2][3] Older versions of Android require LHDC/LLAC enumeration constant symbols to be implemented by the smartphone manufacturers or Android app. Android apps that support LHDC include Savitech's Hi-Res BT Player, FiiO Music, HIFIMAN Music and DA&T Audio.
LHDC
LHDC (also known as HWA) supports bitrates of 400/560/900 kbit/s, bit-depth of up to 24 bit and sample rate of up to 96 kHz.[1]
The first Smartphone to support LHDC was the Huawei Mate 10.[4]
On 17 September 2019, the Japan Audio Society (JAS) certified LHDC with their Hi-Res Audio Wireless certification. Currently the only codecs with the Hi-Res Audio Wireless certification are LHDC and LDAC.[5]
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 of up to 48 kHz. LLAC has no hardware requirement for the transmitter.[6]
The first Smartphone to support LLAC was the Huawei P30.[7]
Hi-Res Wireless Audio (HWA) Union
On 2 September 2018 the Hi-Res Wireless Audio (HWA) Union was formed to promote LHDC adoption.[8] Also known as the HWA Alliance. The HWA Union Board of Directors includes:
Column-generating template families
The templates listed here are not interchangeable. For example, using {{col-float}} with {{col-end}} instead of {{col-float-end}} would leave a <div>...</div> open, potentially harming any subsequent formatting.
| Type | Family | Handles wiki
table code?† |
Responsive/ mobile suited |
Start template | Column divider | End template |
|---|---|---|---|---|---|---|
| Float | "col-float" | Yes | Yes | {{col-float}} | {{col-float-break}} | {{col-float-end}} |
| "columns-start" | Yes | Yes | {{columns-start}} | {{column}} | {{columns-end}} | |
| Columns | "div col" | Yes | Yes | {{div col}} | – | {{div col end}} |
| "columns-list" | No | Yes | {{columns-list}} (wraps div col) | – | – | |
| Flexbox | "flex columns" | No | Yes | {{flex columns}} | – | – |
| Table | "col" | Yes | No | {{col-begin}}, {{col-begin-fixed}} or {{col-begin-small}} |
{{col-break}} or {{col-2}} .. {{col-5}} |
{{col-end}} |
† Can template handle the basic wiki markup {| | || |- |} used to create tables? If not, special templates that produce these elements (such as {{(!}}, {{!}}, {{!!}}, {{!-}}, {{!)}})—or HTML tags (<table>...</table>, <tr>...</tr>, etc.)—need to be used instead.
Other HWA Union members include:
Column-generating template families
The templates listed here are not interchangeable. For example, using {{col-float}} with {{col-end}} instead of {{col-float-end}} would leave a <div>...</div> open, potentially harming any subsequent formatting.
| Type | Family | Handles wiki
table code?† |
Responsive/ mobile suited |
Start template | Column divider | End template |
|---|---|---|---|---|---|---|
| Float | "col-float" | Yes | Yes | {{col-float}} | {{col-float-break}} | {{col-float-end}} |
| "columns-start" | Yes | Yes | {{columns-start}} | {{column}} | {{columns-end}} | |
| Columns | "div col" | Yes | Yes | {{div col}} | – | {{div col end}} |
| "columns-list" | No | Yes | {{columns-list}} (wraps div col) | – | – | |
| Flexbox | "flex columns" | No | Yes | {{flex columns}} | – | – |
| Table | "col" | Yes | No | {{col-begin}}, {{col-begin-fixed}} or {{col-begin-small}} |
{{col-break}} or {{col-2}} .. {{col-5}} |
{{col-end}} |
† Can template handle the basic wiki markup {| | || |- |} used to create tables? If not, special templates that produce these elements (such as {{(!}}, {{!}}, {{!!}}, {{!-}}, {{!)}})—or HTML tags (<table>...</table>, <tr>...</tr>, etc.)—need to be used instead.
HWA Certification
On the 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 using the 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.[9]
See also
External links
References
- ^ a b "What is LHDC". LHDC. Retrieved 2019-09-22.
- ^ Yeow, Goh Beng (2019-10-22). "Android 10 devices are going to sound better with LHDC™". Porta-Fi™. Retrieved 2019-12-22.
- ^ "Audio Implementation". Android Open Source Project. Retrieved 2019-12-22.
- ^ "Product Finder Mobile". hwa-audio. Retrieved 2019-09-22.
- ^ Yeow, Goh Beng (2019-09-17). "Japan Audio Society certifies LHDC™ for "Hi-Res Audio Wireless" certification". Porta-Fi™. Retrieved 2019-09-22.
- ^ "What is LLAC". LHDC. Retrieved 2019-09-22.
- ^ "HWA". hwa-audio. Retrieved 2019-09-22.
- ^ Yeow, Goh Beng (2018-09-01). "Hi-Res Wireless Audio (HWA) Union established". Porta-Fi™. Retrieved 2019-09-22.
- ^ "HWA Certification Grading". hwa-audio. Retrieved 2019-09-22.
{{cite web}}: CS1 maint: url-status (link)