What is G.729?
G.729 is an ITU standardization standard for telecommunications standards used for voice compression and decompression. The technology is used in digital transmission systems and for coding analog to digital signals. G.729 is often used in VoIP applications because of its low bandwidth requirements.
G.729 contains patents from several companies and is licensed from Sipro Lab Telecom. In certain countries, the use of G.729 requires a license or license fee.
The extensions to the G.729 standard include G.729a and G.729 b.
G.72a is a compatible extension of G.729, which requires less computing power, but at the expense of a slightly lower voice quality. It was originally developed by a consortium of organizations including France Telecom, Mitsubishi Electric Corporation, Nippon Telegraph and Telephone Corporation (NTT), and the Université de Sherbrooke. Its main features include a fixed bit rate and a fixed frame size.
G.729b provides silence compression that enables voice activity detection modules to detect voice activity in signals. It also includes a discontinuous transmission module that decides when to update background noise parameters for lack of speech, and uses three-byte silence insertion descriptor frames to initiate the generation of noise.
If the transmission stops and the connection goes silent due to the lack of speech, the receiving end can assume that the transmission has been interrupted. Analog hiss is digitally simulated by inserting comfort noises during silence to ensure the receiver that connections are active and operational.
G.729 is also being expanded to provide support for broadband voice and audio coding.