Re: [rtcweb] JSEP: Issues with a=ssrc and RTP payload type switching

[Harald Alvestrand <[e-mail]>]

Den 08. juni 2015 17:15, skrev Simon Perreault:
> Le 2015-06-08 09:09, Harald Alvestrand a écrit :
>> This has another implication:
>>
>> When doing PT switching for comfort noise, you MUST have a CN with the
>> same clock rate as your normal audio codec.
>>
>> CN is exactly the type of PT-switching that, if it occurs at all, occurs
>> very frequently.
> 
> I'm not following. We're discussing generating a new SSRC on clock
> rate-switching, not on PT-switching. For the CN example, you would
> typically include in your SDP one CN payload type per possible clock
> type so that you can switch payload types without switching the clock rate.

Yep. It's only because I've seen SDP trying to match CN/8000 with
OPUS/48000 that I'm mentioning it - it's obvious, but only after it's
bitten you.