Audio Codecs - Matrix Sparsh VP110 User Manual

Audio Codecs

CODEC is an abbreviation of COmpress-DECompress, capable of coding or decoding a digital data stream or
signal by implementing an algorithm. The object of the algorithm is to represent the high-fidelity audio signal with
minimum number of bits while retaining the quality. This can effectively reduce the frame size and the bandwidth
required for audio transmission.
The default codecs used on IP phones are summarized in the following table:
Codec
PCMA
PCMU
G729
G722
In addition to the codecs introduced above, IP phones also support codecs: G723_53, G723_63, G726-32. Codecs
and priorities of these codecs are configurable. The attribute "rtpmap" is used to define a mapping from RTP
payload codes to a codec, clock rate and other encoding parameters.
The corresponding attributes of the codec are listed as follows:
Codec
PCMU
PCMA
G729
G722
G723_53
G723_63
286
Algorithm Bit Rate
G.711 a‐law 64 Kbps
64 Kbps
G.711 ‐law
G.729 8 Kbps
G.722 64 Kbps
Configuration Methods
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Sample Rate
8 Ksps
8 Ksps
8 Ksps
16 Ksps
Priority RTPmap
1
0
2 8
3 18
4 9
0 4
0 4
Matrix SPARSH VP110 User Guide
Packetization Time
20ms
20ms
20ms
20ms