To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

From Wikipedia, the free encyclopedia

G.723.1 is an audio codec for voice that compresses voice audio in 30 ms frames. An algorithmic look-ahead of 7.5 ms duration means that total algorithmic delay is 37.5 ms. Its official name is Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s. It is sometimes associated with a Truespeech trademark in coprocessors produced by DSP Group.[1]

This is a completely different codec from G.723.

There are two bit rates at which G.723.1 can operate:

  • 6.3 kbit/s (using 24 byte frames) using a MPC-MLQ algorithm (MOS 3.9)
  • 5.3 kbit/s (using 20 byte frames) using an ACELP algorithm (MOS 3.62)


G.723.1 is mostly used in Voice over IP (VoIP) applications due to its low bandwidth requirement. Music or tones such as DTMF or fax tones cannot be transported reliably with this codec, and thus some other method such as G.711 or out-of-band methods should be used to transport these signals. The complexity of the algorithm is below 16 MIPS. 2.2 kilobytes of RAM is needed for codebooks.

G.723.1 is a required audio codec in the H.324 ITU-T recommendation for H.324 terminals offering audio communication. In 3GPP 3G-324M specification support for G.723.1 is not mandatory, but recommended.


  • Sampling frequency 8 kHz/16-bit (240 samples for 30 ms frames)
  • Fixed bit rate (5.3 kbit/s with 20 byte 30 ms frames, 6.3 kbit/s with 24 byte 30 ms frames)
  • Fixed frame size for each rate (5.3 kbit/s with 20 byte 30 ms frames, 6.3 kbit/s with 24 byte 30 ms frames)
  • Algorithmic delay is 37.5 ms per frame, with 7.5 ms look-ahead delay
  • G.723.1 is a hybrid speech coder, with high bit rate using multi-pulse maximum likelihood quantization (MP-MLQ) and low bit rate using algebraic code-excited linear prediction (ACELP)
  • The complexity of the algorithm is rated at 25, using a relative scale where G.711 is 1 and G.729a is 15.
  • G.723.1 Annex A defines 4 byte silence insertion descriptor (SID) frame for Comfort Noise Generation
  • PSQM testing under ideal conditions yields mean opinion scores of 4.08 for G.723.1 (6.3 kbit/s), compared to 4.45 for G.711 (μ-law)
  • PSQM testing under network stress yields mean opinion scores of 3.57 for G.723.1 (6.3 kbit/s), compared to 4.13 for G.711 (μ-law)


As of January 1, 2017, the patent terms of most patents applying to G.723.1 have expired. With regard to the unexpired licensed patents of their G.723.1 patent license agreement, the licensors of G.723.1 patents, namely AudioCodes, Orange SA, and Université de Sherbrooke have agreed to license their patents under the existing terms on a royalty-free basis starting January 1, 2017.[2]

The authorized intellectual property rights (IPR) licensing administrator for G.723.1 technology is Sipro Lab Telecom.[3][4][5]

Members of the G.723.1 patent pool are AudioCodes, France Telecom, Université de Sherbrooke, Nippon Telegraph and Telephone Corporation and Nokia.[6]

See also


  1. ^ "CT8022 VOIP/VON G.723.1, G729AB TRUESPEECH® CO-PROCESSOR" (PDF). Archived from the original (PDF) on 4 April 2018. Retrieved 4 April 2018. The CT8022 has built-in TrueSpeech 8.5 (compatible with Microsoft Sound System 2.0, and a standard part of Microsoft Windows 95), and TrueSpeech G.723.1 (for H.323 and H.324). [...] The CT8022 provides two additional non-ITU TrueSpeech data rates at 4.8 and 4.1 KBPS.
  2. ^ "SiproLAB Telecom - patent pool creation and management for standardized telecommunication technologies". 2017-12-22. Retrieved 2018-01-10.
  3. ^ VoiceAge Corporation (2007-10-14). "G.723.1 Licensing". Archived from the original on 2007-10-14. Retrieved 2009-09-17.
  4. ^ Sipro Lab Telecom (2007-10-25). "FAQ G.729 and G.723.1". Archived from the original on 2007-10-25. Retrieved 2009-09-17.
  5. ^ Sipro Lab Telecom (2006-10-29). "G.723.1, the highest ITU-T compression ratio". Archived from the original on 2006-10-29. Retrieved 2009-09-17.
  6. ^ Sipro Lab Telecom (2006-10-29). "G.723.1 - Members". Archived from the original on 2006-10-29. Retrieved 2009-09-17.

External links

This page was last edited on 13 December 2020, at 05:53
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.