Jump to content

LDAC (codec)

From Wikipedia, the free encyclopedia
(Redirected from Sony LDAC)

LDAC
Developed bySony
Type of formatAudio codec

LDAC (Lossless Digital Audio Codec) 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.

The encoder of LDAC is open-source under Apache License 2.0, so that any device can be coded to transmit LDAC streams without patent or licensing issues. The decoder design remains proprietary.

Audio coding

[edit]

LDAC is an alternative to Bluetooth SIG's SBC codec. Its main competitors are Huawei's L2HC, Qualcomm's aptX-HD/aptX Adaptive and the HWA Union/Savitech's LHDC.[1]

LDAC utilizes a type of lossy compression[2][3] by employing a hybrid coding scheme based on the modified discrete cosine transform[4] and Huffman coding[5] to provide more efficient data compression. By default, LDAC audio bitrate settings are set to Best Effort, which switches between discrete bitrate steps (CBR) 330/660/990 kbps depending on connection strength;[6] however, audio bitrate and resolution can be manually adjusted on Linux (when using PipeWire[7]), some Android platforms (which generally requires access to the "Developer Settings" menu), and Sony's own smartphones and Walkman devices at the following rates; 330/660/990 kbps at 96/48 kHz and 303/606/909 kbps at 88.2/44.1 kHz with depth of 32, 24 or 16 bits.[6]

Starting from Android 8.0 "Oreo", LDAC is part of the Android Open Source Project, enabling every OEM to integrate this standard into their own Android devices freely.[5][8] The encoder library is open source and the implementation for Linux is already present in bluez-alsa,[9] pulseaudio-modules-bt,[10][11] and in PipeWire's bluez5 module.[12][13] It is available on Fedora since Fedora 29.[14] However the decoder library is proprietary, so receiving devices require licenses.[15]

On 17 September 2019, the Japan Audio Society (JAS) certified LDAC with their Hi-Res Audio Wireless certification.[16] 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.[17]

See also

[edit]

References

[edit]
  1. ^ "Best Wireless Headphones of 2018". 13 November 2017. Retrieved 9 March 2018.
  2. ^ Darko, John H. (29 March 2017). "The inconvenient truth about Bluetooth audio". DAR__KO. Retrieved 13 January 2018.
  3. ^ "What is Sony LDAC, and how does it do it?". AVHub. 24 August 2015. Retrieved 13 January 2018.
  4. ^ "src/ldaclib_api.c - platform/external/libldac". android Git repositories - Git at Google.
  5. ^ a b Triggs, Robert (22 August 2017). "What you need to know about Sony's LDAC". Android Authority. Retrieved 8 January 2021.
  6. ^ a b Triggs, Robert (16 December 2018). "The ultimate guide to Bluetooth headphones: LDAC isn't Hi-res". SoundGuys. Retrieved 22 September 2019.
  7. ^ "Releases · PipeWire / pipewire". GitLab. Retrieved 11 June 2021.
  8. ^ "platform/external/libldac". android Git repositories - Git at Google. Retrieved 30 November 2018.
  9. ^ "LDAC support? · Issue #104 · Arkq/bluez-alsa". GitHub. Retrieved 20 March 2019.
  10. ^ H.H, Bao (20 March 2019), Adds Sony LDAC, aptX, aptX HD, AAC codecs (A2DP Audio) support to PulseAudio on Linux: EHfive/pulseaudio-modules-bt, retrieved 20 March 2019
  11. ^ eischmann (11 February 2019). "Better Bluetooth sound quality on Linux". Brno hat. Retrieved 20 March 2019.
  12. ^ "List of commits on the PipeWire project pertaining to LDAC support". freedesktop.org Gitlab. 31 December 2020. Retrieved 31 December 2020.
  13. ^ "Achieve parity and/or surpass PulseAudio in Bluetooth audio support". 31 December 2020. Retrieved 31 December 2020.
  14. ^ "1671064 – Review Request: libldac - LDAC library from AOSP". bugzilla.redhat.com. Retrieved 20 March 2019.
  15. ^ "Audio over Bluetooth: most detailed information about profiles, codecs, and devices". habr.com. Retrieved 9 May 2020.
  16. ^ Yeow, Goh Beng (17 September 2019). "Japan Audio Society certifies LHDC™ for "Hi-Res Audio Wireless" certification". Porta-Fi™. Retrieved 22 September 2019.
  17. ^ "Definition of Hi-Res Audio (Announced on June 12th 2014)". Japan Audio Society. 12 June 2024. Retrieved 26 June 2024.
[edit]
Retrieved from "https://wiki.riteme.site/w/index.php?title=LDAC_(codec)&oldid=1266444514"