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.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.
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