[asterisk-dev] Opus and VP8

Andrea Suisani sickpig at opinioni.net
Wed Jun 19 08:12:39 CDT 2013


Hi Lorenzo,


On 06/06/2013 04:31 PM, Lorenzo Miniero wrote:
> 2013/6/6 Andrea Suisani <sickpig at opinioni.net <mailto:sickpig at opinioni.net>>
>
>     On 06/06/2013 11:32 AM, Andrea Suisani wrote:
>
>         On 06/06/2013 11:17 AM, Lorenzo Miniero wrote:
>
>             core show translation paths opus
>
>
>         I'm in a hurry.
>         just to give you other elements on which speculate further
>
>         suino*CLI> core show translation paths opus
>         --- Translation paths SRC Codec "opus" sample rate 48000 ---
>
>                                                           ^^^^^^
>                                                           ^^^^^^
>
>     I suddenly realized that for some reason the only enabled sample
>     rate is 48 kHz, is it poissible ?
>
>
> 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. 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.
>
> 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).

I just want let you know I've opened an issue related to this problem on github patch repo:

https://github.com/meetecho/asterisk-opus/issues/2


Andrea



More information about the asterisk-dev mailing list