[SIP Beyond VoIP] opus codec negotiation

James Cloos cloos at jhcloos.com
Fri Jun 13 00:55:36 CEST 2014

>>>>> "SIC" == Saúl Ibarra Corretgé <saul at ag-projects.com> writes:

SIC> Opus is supposed to always support stereo, but downgrade to mono if
SIC> necessary. Initially the draft stated that the codec was suppodes to
SIC> not be offered as stereo (the /2) and then that changed. The testing I
SIC> did back then showed that this way (without the /2) yielded better
SIC> interoperability. With the proliferation of more Opus capable
SIC> endpoints, maybe this doesn't hold true anymore.

If the endpoints which do not offer /2 do not know that they can accept
it anyway they will not agree to such an offer.

SIC> Regardless, I thought I had tricked Blink into also accepting calls
SIC> with the /2 in there :-S I'll take a look.

It was the obvious difference; that doesn't guarantee that my hypothesis
actually *is* why they didn't agree on opus.  Perhaps there is something
less immediately obvious?

Incidently, did they let the opus/rtp draft expire w/o a new version?

James Cloos <cloos at jhcloos.com>         OpenPGP: 0x997A9F17ED7DAEA6

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