[asterisk-dev] Opus and VP8

[Andrea Suisani]

> As I said in other posts, Opus is always advertized as 48kHz, and the timestamps in RTP always increase as if the rate actually was 48kHz,
 > even when lower rates (e.g. 16kHz wideband) are actually being used.
> This is specified in the Opus RTP draft, and Asterisk is configured accordingly.

check

> The output you see there just means that Asterisk looks at Opus as a 48kHz codec, so it's normal.
> The actual sampling rate being used is taken care of by the codec implementation.

got it

> In your case, a opus<->slin48 translation is created, which means that Opus frames are likely to be exactly, or close to,
> 48kHz in rate. When a opus<->8000 translation is created, Opus frames should be narrowband instead (while, as anticipated,
 > the SDP negotiation and the timestamps would still refer to a 48kHz sampling rate).

so as you stated in a prev email the Opus codec implementation should
automatically switch to a 8 kHz sample rate once it realize that the peer
is using a codec that works with a 8 kHz sampling rate (e.g. GSM/ulaw/g729)

his auto-adjustment seems to not work correctly in my env.

thanks for the explanation, I will try to test it properly
starting from a fresh asterisk installation and I'll report back

Andrea