| G.723.1 | |
|---|---|
| Dual rate speech coder for multimedia communications transmitting at 5.3 and6.3 kbit/s | |
 | |
| Status | In force |
| Year started | 1996 |
| Latest version | (05/06) May 2006 |
| Organization | ITU-T |
| Base standards | G.721 |
| Related standards | G.726 |
| Domain | audio compression |
| License | Freely available |
| Website | https://www.itu.int/rec/T-REC-G.723.1 |
G.723.1 is an audiocodec for voice that compresses voice audio in30 ms frames. An algorithmic look-ahead of7.5 ms duration means that total algorithmic delay is37.5 ms.[1] Its official name isDual rate speech coder for multimedia communications transmitting at 5.3 and6.3 kbit/s. It is sometimes associated with aTruespeech trademark in coprocessors produced byDSP Group.[2]
This is a completely different codec fromG.723.
There are twobit rates at which G.723.1 can operate:
G.723.1 is mostly used in Voice over IP (VoIP) applications due to its low bandwidth requirement. Music or tones such asDTMF orfax tones cannot be transported reliably with this codec, and thus some other method such asG.711 orout-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 theH.324 ITU-T recommendation for H.324 terminals offering audio communication. In3GPP3G-324M specification support for G.723.1 is not mandatory, but recommended.
As of January 1, 2017, thepatent 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.[3]
The authorizedintellectual property rights licensing administrator for G.723.1 technology is Sipro Lab Telecom.[4][5][6]
Members of the G.723.1patent pool areAudioCodes,France Telecom,Université de Sherbrooke,Nippon Telegraph and Telephone Corporation andNokia.[7]
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.
