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List:       asterisk-dev
Subject:    Re: [asterisk-dev] Asterisk 14.0.1 Now Available
From:       Alexander Traud <pabstraud () compuserve ! com>
Date:       2016-10-31 21:20:27
Message-ID: A48AFD3B-65B1-4011-A7AC-8BEA87AC83B7 () compuserve ! com
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> Has anybody updated the version of the [Opus transcoding] patch for 14 and/or \
> master?

<https://github.com/traud/asterisk-opus>

The story continues there. I updated the code and I try my best to maintain that fork \
(because I use it myself). Currently, it should be compatible from 13.7 up to the \
latest 14 and Master version. If not, please, create an Issue Report or a Pull \
Request. Other contributions are welcome as well.

> it does take a small bits of maintenance


If there is anything I could do, to ease that, please do not hesitate.

> Opus is to become the new standard audio codec.

I know, you want to persuade Digium to give more attention to that audio codec and \
its features (Native PLC, Adaptive FEC, VAD/DTX/CNG). Yes, those features of a Media \
Gateway are important not only to Opus but other audio codecs as well, like 3GPP EVS. \
Actually, because of the complexity of modern  audio codecs (since the end of the \
nineties with the introduction of G.729), such features are a must-have. Without \
those features, distortion is a common issue with modern audio codecs.

Furthermore, I cannot restrain to comment on that statement: I am quite skeptical \
about the future of Opus. Currently, it is there because of WebRTC. Full stop! Mobile \
phones go for GSM, AMR, AMR-WB, and last years 3GPP EVS. Landline phones go for and \
continue to use G.711, G.726-32, G.722. If Opus gets lucky, the industry chooses Opus \
for multi-channel and music via landline. However last year, for music, the German \
company AVM went not for Opus but for its precursor CELT.


Finally, from my experiences with several implementations, Opus Codec seems to be \
quite challenging. Not many implementations leverage the parameter negotiation via \
the SDP attribute fmtp. It was a bit of work to add that to Asterisk, by the way. \
Therefore sometimes, tailoring of the Opus Codec is impossible and the data rate goes \
through the sky. When it comes to wide-band audio codecs, G.722 and AMR-WB might stay \
the winners because they are more limited.

Nevertheless, I would have nothing against a single audio codec for VoIP/SIP  - \
finally.


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