- From: Barry Dingle <btdingle@gmail.com>
- Date: Thu, 23 Jan 2014 23:32:24 +1100
- To: "Cullen Jennings (fluffy)" <fluffy@cisco.com>
- Cc: Gunnar Hellstrom <gunnar.hellstrom@omnitor.se>, Roman Shpount <roman@telurix.com>, Mike Johns <m.johns@commsalliance.com.au>, "public-webrtc@w3.org" <public-webrtc@w3.org>
- Message-ID: <CAN=GVAvvHZf-K12uskz_h5kT-XBeAXYNSXzPggeTK+-PbntQMQ@mail.gmail.com>
Thanks Cullen. I will wake our Regulatory people up to this issue when they return from their Summer Holiday slumbers and try to get them to respond. Cheers, /Barry Barry Dingle Fixed - +61(0)3-9725-3937 Mob - +61(0)41-911-7578 Fellow of University of Melbourne, Electrical and Electronic Eng., Australia > Linux + Android + Apple + Open Source software On Thu, Jan 23, 2014 at 2:50 AM, Cullen Jennings (fluffy) <fluffy@cisco.com>wrote: > > > OK - Here is my proposed text. > > The duration parameter indicates the duration in ms to use for > each character passed in the tones parameters. The duration > cannot be > more than 6000 ms or less than 40 ms. The default duration is > 100 ms > for each tone. > > The interToneGap parameter indicates the gap between tones. It > MUST be at least 30 ms. The default value is 70 ms. > > The browser MAY increase the duration and interToneGap times to > cause the times that DTMF start and stop to align with the > boundaries > of RTP packets but it MUST not increase either of them by more > than > the duration of a single RTP audio packet. > > That close enough for now? > > Barry, don’t worry, it will be awhile before this spec is done and in a > month or so if we find out this has a problem, we can still fix it. > > > On Jan 20, 2014, at 4:17 AM, Barry Dingle <btdingle@gmail.com> wrote: > > > Gunnar, > > > > I agree with you and Roman. What you suggest appears to cover the > Australian DTMF case. My only hesitation is that I cannot reply on behalf > of Australian Industry. (Everyone 'in authority' is on Summer Leave at the > moment !!) > > > > Cheers, > > /Barry Dingle > > "Australia" > > > > Gunnar Hellstrom <gunnar.hellstrom@omnitor.se> wrote: > > On 2014-01-19 20:06, Roman Shpount wrote: > >> On Fri, Jan 17, 2014 at 12:44 PM, Roman Shpount <roman@telurix.com> > wrote: > >> On Fri, Jan 17, 2014 at 12:35 PM, Cullen Jennings (fluffy) < > fluffy@cisco.com> wrote: > >> > >> I’m fine with lower limits allowing people to shoot themselves in the > feet but I want the defaults to be safe for most cases. > >> > >> So the way I think we should set this is to set the default to be > "safe" for all major deployments world wide. And have the minimum values > allow you set it to be as low as is usable in any any major deployment > world wide. With that strategy, and the information folks provided in this > email thread, I think we get to the following. > >> > >> How about this for a proposed change: > >> > >> We change the min tone time to 40 ms. > >> > >> We change the min gap time to 30 ms. > >> > >> We change the default gap to 70 ms (this meets Australia AS/CA S0020) > >> > >> We leave the default tone duration at 100 ms. > >> > >> Does that change look OK to folks? > >> > >> > >> This looks perfect to me. > >> > >> > >> After I thought about this a little bit more I would suggest that tone > and gap generation should take the packet ptime into account. The reason is > that WebRTC will switch between RFC 4733 tone and audio codec during the > pause. This means for 70 ms pauses and most common ptime of 20 ms we will > end up with a 10 ms audio packet. Packets of duration other then ptime have > a tendency to cause interop issues. In our implementations of similar DTMF > generation code we would round up gap and tone duration to the next ptime > interval, so that with 20 ms ptime you can set the gap to 40, 60, 80, 100 > ms (etc) and tone duration to 40, 60, 80, 100 ms (etc). With 30 ms ptime it > would be 30, 60, 90 ms (etc) for the gap and 60, 90, 120 ms (etc) for the > tone. > > Yes, this seems right. > > The WebRTC API spec should then just mention the rounding of the > durations and alignment with the ptime, and the IETF RTCWEB audio spec > should be specific about how to do the interleaving and relative timing of > audio and DTMF. > > > > So, for the API spec: > > Default duration is 100 ms and default gap is 70 ms. The transmission > timing and duration used will be aligned by extension if needed to use the > same packet transmission time and interval as the audio stream. > > > > And the details in an RTCWEB spec. > > > > /Gunnar > >> _____________ > >> Roman Shpount > >> > > > > > >
Received on Thursday, 23 January 2014 12:33:13 UTC