[asterisk-users] codec_opus w/ PLR and FEC for Asterisk 11

sean darcy seandarcy2 at gmail.com
Thu Apr 28 07:30:33 CDT 2016

There is an opus patch for asterisk 11. 
https://github.com/seanbright/asterisk-opus/tree/asterisk-11 . But it 
doesn't have Packet Loss Resilience or Forward Error Correction, both of 
which are important for voip.

2.1.6.  Packet Loss Resilience

Audio codecs often exploit inter-frame correlations to reduce the 
bitrate at a cost in error propagation: after losing one packet, several 
packets need to be received before the decoder is able to accurately 
reconstruct the speech signal. The extent to which Opus exploits 
inter-frame dependencies can be adjusted on the fly to choose a 
trade-off between bitrate and amount of error propagation.

2.1.7.  Forward Error Correction (FEC)

Another mechanism providing robustness against packet loss is the 
in-band Forward Error Correction (FEC). Packets that are determined to 
contain perceptually important speech information, such as onsets or 
transients, are encoded again at a lower bitrate and this re-encoded 
information is added to a subsequent packet.

There is an opus patch for asterisk 13 that includes PLR and FEC. 

We don't have approval to move to 13. So anybody have an opus patch for 
11 that includes PLR and FEC ?


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