G.723.1 is an audio

codec A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or ...

for voice that compresses voice audio in frames. An algorithmic look-ahead of duration means that total algorithmic delay is . Its official name is ''Dual rate speech coder for multimedia communications transmitting at 5.3 and ''. It is sometimes associated with a Truespeech trademark in coprocessors produced by DSP Group. This is a completely different codec from

G.723 G.723 is an ITU-T standard speech codec using extensions of G.721 providing voice quality covering 300 Hz to 3400 Hz using Adaptive Differential Pulse Code Modulation (ADPCM) to 24 and 40 kbit/s for digital circuit multiplication equip ...

. There are two bit rates at which G.723.1 can operate: * (using 24-byte frames) using a MPC-MLQ algorithm (

MOS MOS or Mos may refer to: Technology * MOSFET (metal–oxide–semiconductor field-effect transistor), also known as the MOS transistor * Mathematical Optimization Society * Model output statistics, a weather-forecasting technique * MOS (filmm ...

3.9) * (using 20-byte frames) using an

ACELP Algebraic code-excited linear prediction (ACELP) is a speech coding algorithm in which a limited set of pulses is distributed as excitation to a linear prediction filter. It is a linear predictive coding (LPC) algorithm that is based on the cod ...

algorithm (

3.62)

Use

G.723.1 is mostly used in Voice over IP (

VoIP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...

) applications due to its low bandwidth requirement. Music or tones such as

DTMF Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed ...

fax Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

tones cannot be transported reliably with this codec, and thus some other method such as

G.711 G.711 is a narrowband audio codec originally designed for use in telephony that provides toll-quality audio at 64 kbit/s. G.711 passes audio signals in the range of 300–3400 Hz and samples them at the rate of 8,000 samples per second ...

out-of-band Out-of-band activity is activity outside a defined telecommunications frequency band, or, metaphorically, outside of any primary communication channel. Protection from falsing is among its purposes. Examples General usage * Out-of-band agreement ...

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 3G-324M is the 3GPP umbrella protocol for video telephony in 3G mobile networks. The 3G-324M protocol operates over an established circuit switched connection between two communicating peers. 3G-324M is an umbrella specification to enable conv ...

specification support for G.723.1 is not mandatory, but recommended.

Features

* Sampling frequency /16-bit (240 samples for frames) * Fixed bit rate ( with 20 byte frames, with 24 byte frames) * Fixed frame size for each rate ( with 20 byte frames, with 24 byte frames) * Algorithmic delay is per frame, with 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

is 1 and

G.729a G.729 is a royalty-free narrow-band vocoder-based audio data compression algorithm using a frame length of 10 milliseconds. It is officially described as ''Coding of speech at 8 kbit/s using code-excited linear prediction'' speech coding (CS-ACEL ...

is 15. * G.723.1 Annex A defines 4 byte silence insertion descriptor (SID) frame for Comfort Noise Generation *

PSQM Perceptual Speech Quality Measure (PSQM) is a computational and modeling algorithm defined in Recommendation ITU-T P.861 that objectively evaluates and quantifies voice quality of voice-band (300 – 3400 Hz) speech codecs. It may be used to ...

testing under ideal conditions yields

mean opinion score Mean opinion score (MOS) is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a stimulus or system. It is the arithmetic mean over all individual "values on a predefined scale t ...

s of 4.08 for G.723.1 (), compared to 4.45 for

( μ-law) * PSQM testing under network stress yields

s of 3.57 for G.723.1 (), compared to 4.13 for

( μ-law)

Licensing

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. The authorized

intellectual property rights Intellectual property (IP) is a category of property that includes intangible creations of the human intellect. There are many types of intellectual property, and some countries recognize more than others. The best-known types are patents, cop ...

licensing administrator for G.723.1 technology is Sipro Lab Telecom. Members of the G.723.1

patent pool In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking ...

are AudioCodes,

France Telecom Orange S.A. (), formerly France Télécom S.A. (stylized as france telecom) is a French multinational telecommunications corporation. It has 266 million customers worldwide and employs 89,000 people in France, and 59,000 elsewhere. In 2015, ...

Université de Sherbrooke The University of Sherbrooke (French: Université de Sherbrooke) (UdS) is a large public French-language university in Quebec, Canada with campuses located in Sherbrooke and Longueuil, a suburb of Montreal approximately west of Sherbrooke. It i ...

, Nippon Telegraph and Telephone Corporation and

Nokia Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...

References

External links

ITU-T Recommendation G.723.1
- technical specification

page on ITU website (with link to patent declaration database) {{Authority control Audio codecs Speech codecs ITU-T recommendations ITU-T G Series Recommendations

Use

Features

Licensing

See also

References

External links