G. 729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. For processes which reduce the amount of time it takes to listen to and understand a recording see Time-compressed speech. Music or tones such as DTMF or fax tones cannot be transported reliably with this codec, and thus use G.711 or out-of-band methods to transport these signals. Dual-tone multi-frequency ( DTMF) signaling is used for Telephone signaling over the line in the voice-frequency band to the call switching center Fax (short for facsimile, from Latin fac simile, "make similar" i A codec is a device or program capable of encoding and/or decoding a Digital Data stream or signal. G711 is an ITU-T standard for audio Companding. It is primarily used in Telephony. Out-of-band is a technical term with different uses in Communications and Telecommunication.
G. 729 is mostly used in Voice over IP (VoIP) applications for its low bandwidth requirement. Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet Standard G. 729 operates at 8 kbit/s, but there are extensions, which provide also 6. In Telecommunications and Computing, bitrate (sometimes written bit rate, data rate or as a Variable R or f b 4 kbit/s and 11. 8 kbit/s rates for marginally worse and better speech quality respectively. Also very common is G.729a which is compatible with G. G729a is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds 729, but requires less computation. This lower complexity is not free since speech quality is marginally worsened.
The annex B of G. 729 is a silence compression scheme, which has a VAD module which is used to detect voice activity, speech or non speech. Silence is a relative or total lack of audible Sound you can not hear a thing it is quiet Voice activity detection (also known as speech activity detection or more simply speech detection is an algorithm used in Speech processing wherein the presence or absence It also includes a DTX module which decides on updating the background noise parameters for non speech (noisy frames). Discontinuous transmission (DTX is a method of momentarily powering-down or muting a mobile or portable wireless telephone set when there is no voice input to the set In atmospheric sound transmission or Noise pollution, ambient noise level is the sound pressure level at a given location normally specified as a reference level to study a These frames which are transmitted to update the background noise parameters are called SID frames. In Computer networking, a frame is a Data packet of fixed or variable length which has been encoded by a Data link layer communications protocol for digital A comfort noise generator (CNG) is also there because in a communication channel, if transmission is stopped, because it's not speech, then the other side may assume that link has been cut. Comfort noise (or comfort tone) is artificial background Noise used in Radio and Wireless communications to fill the Silence in a Channel, in communications (sometimes called communications channel) refers to the medium used to convey Information from a This is also taken care of by the annex B standard.
Recently, G. 729 has been extended to provide support for wideband speech and audio coding, i. e. , the transmitted acoustic frequency range is extended to 50 Hz - 7 kHz. The respective extension to G. 729 is referred to as G.729.1. G7291 is an 8-32 kbit/s embedded speech and audio coderproviding bitstream interoperability with G The G. 729. 1 coder is hierarchically organized: Its bit rate and the obtained quality are adjustable by simple bitstream truncation.
G. 729 is patented by Sipro (http://www.sipro.com/) in a number of countries. Software patent does not have a universally accepted definition The use of G. 729 may require a license fee and/or royalty fee.
See also
- G.711
- G.722
- G.722.1
- G.723
- G.723.1
- G.726
- G.728
- G. G711 is an ITU-T standard for audio Companding. It is primarily used in Telephony. G722 is a ITU-T standard wideband speech Codec operating at 48 56 and 64 kbit/s G7221 is a licensed royalty-free ITU-T standard audio codec providing high quality moderate bit rate (24 and 32 kbit/s wideband (50 Hz - 7 kHz audio bandwidth 16 ksps audio coding G723 is a ITU-T standard speech Codec. This is an extension of Recommendation G G7231 is an audio Codec for voice that compresses voice audio in 30 ms frames G726 is an ITU-T ADPCM Speech codec standard covering the transmission of voice at rates of 16 24 32 and 40 kbit/s G728 is a ITU-T Standard for speech coding operating at 16 kbit /s 729
- G.729a
- G.729.1
- List of codecs
- AMR
- AMR-WB
- EFR
- FR
- iLBC
- GSM
- Speex
- EVRC
External links
- ITU-T G.729 page
- G.729 Error Recovery for Internet Telephony
- ITU Patent database
- Sipro administers the patent pool for G.723.1 and G.729
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