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G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. 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. Audio compression is a form of data compression designed to reduce the size of audio files. ...
Dual-tone multi-frequency (DTMF), also known as Touch Tone® is used for telephone signaling over the line in the voice frequency band to the call switching center. ...
A Samsung fax machine. ...
A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ...
G.711 is an ITU-T standard for audio companding. ...
In telecommunications, the term out-of-band signaling has the following meanings: 1. ...
G.729 is mostly used in Voice over IP (VoIP) applications for its low bandwidth requirement. Standard G.729 operates at 8 kbit/s, but there are extensions, which provide also 6.4 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.729, but requires less computation. This lower complexity is not free since speech quality is marginally worsened. It has been suggested that Internet phone be merged into this article or section. ...
In telecommunications and computing, bit rate (sometimes written bitrate) is the frequency at which bits are passing a given (physical or metaphorical) point. It is quantified using the bit per second (bit/s) unit. ...
G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ...
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. It also includes a DTX module which decides on updating the background noise parameters for non speech (noisy frames). These frames which are transmitted to update the background noise parameters are called SID frames. 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. This is also taken care of by the annex B standard. Silence is a relative or total lack of sound. ...
Voice activity detection or voice activity detector is an algorithm used in speech processing wherein, the presence or absence of human speech is detected from the audio samples. ...
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 telecommunication, ambient noise level or room noise level is the level of acoustic noise existing at a given location, such as in a room, in a compartment, or at a place out of doors. ...
In telecommunications, a frame is a packet which has been encoded for transmission over a particular link. ...
Comfort noise is artifical background noise used in radio and wireless communications to fill the silent time in a transmission resulting from voice activity detection. ...
A Communications channel (or channel for short), models the medium through which information is transmitted from a sender (or transmitter) to a receiver. ...
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 50Hz-7kHz. The respective extension to G.729 is referred to as G.729.1. The G.729.1 coder is hierarchically organized: Its bit rate and the obtained quality are adjustable by simple bitstream truncation. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
Licensing
Use of G.729.1 requires a license for the patents that cover the algorithm.
See also G.711 is an ITU-T standard for audio companding. ...
G.722 is a ITU-T standard wideband speech codec operating at 32-64 kbit/s. ...
G.722. ...
This article is in need of attention from an expert on the subject. ...
G.723. ...
G.726 is ITU-T speech codec operating at bit rates of 16-40 kbit/s. ...
G.728 is a ITU-T standard for speech coding operating at 16 kbit/s. ...
G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
The following is a list of codecs. ...
Adaptive Multi-Rate (AMR) is a Audio data compression scheme optimized for speech coding. ...
Adaptive Multi Rate - WideBand or AMR-WB is a speech coding standard developed after the AMR using same technology like ACELP. The codec provides excellent speech quality due to wider speech bandwidth of 50 - 7000 Hz compared to narrowband speech codecs which in general are optimized for POTS wireline quality...
Enhanced Full Rate or EFR or GSM-EFR is a speech coding standard that was developed in order to improve the quite poor quality of GSM-Full Rate (FR) codec. ...
Full Rate or FR or GSM-FR was the first digital speech coding standard used in GSM digital mobile phone system. ...
The Internet Low Bit Rate Codec (iLBC) is a royalty free narrowband speech codec, developed by Global IP Sound (GIPS). ...
Not to be confused with Get Some Mates The Global System for Mobile Communications (GSM) is the most popular standard for mobile phones in the world. ...
Speex is a free software speech codec that claims to be unencumbered by patent restrictions. ...
EVRC (which stands for Enhanced Variable Rate CODEC) is a speech codec used by CDMA networks. ...
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