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RE: V2 of DTMF - the "Object Oriented" approach

From: Sunyang (Eric) <eric.sun@huawei.com>
Date: Tue, 20 Nov 2012 01:53:27 +0000
To: Stefan Hakansson LK <stefan.lk.hakansson@ericsson.com>, "public-webrtc@w3.org" <public-webrtc@w3.org>
Message-ID: <9254B5E6361B1648AFC00BA447E6E8C32AED84AB@szxeml545-mbx.china.huawei.com>


> -----Original Message-----
> From: Stefan Hakansson LK [mailto:stefan.lk.hakansson@ericsson.com]
> Sent: Friday, November 16, 2012 9:30 PM
> To: public-webrtc@w3.org
> Subject: Re: V2 of DTMF - the "Object Oriented" approach
> 
> I think this is starting to become baked enough to be incorporated in
> the Editor's draft. A couple of minor comments in-line.
> 
> Stefan
> 
> On 11/16/2012 12:56 PM, Harald Alvestrand wrote:
> > I realized that I'd forgotten about the callback / event aspect of the
> > DTMFSender!
> >
> > Feedback so far:
> > - No need to inherit from MediaStreamTrack
> > - Name's ugly, but we can live with it
> >
> > If we don't need to inherit, name can be a little nicer. I like to keep
> > the RTC prefix.
> >
> > Modified version:
> >
> > On 11/14/2012 03:46 PM, Harald Alvestrand wrote:
> >> Takeaways from Lyon were that:
> >>
> >> - Executing DTMF needs reference to an audio track (to know where to
> >> send the data) and to a PeerConnection (to know that we've
> >> successfully negotiated use of the DTMF codec).
> >> - The WG preferred an "object oriented" model: creating a DTMF handler
> >> object, rather than the "fortran" approach of having all functions
> >> directly on the PeerConnection.
> >>
> >> Suggested edits, delta from the October 19 version of the spec:
> >>
> >> - In section 8.4, rename AudioMediaStreamTrack to RTCDTMFSender.
> >> Remove inheritance.
> >> Add the following text:
> >>
> >> A RTCDTMFSender is created by calling the createDTMFSender() method
> on
> >> a PeerConnection. This constructs an object that exposes the functions
> >> required to send DTMF.
> > NEW IN THIS VERSION:
> >
> > Add to RTCDTMFSender:
> >
> >     attribute EventHandler ontonechange;
> >
> > Add text under 8.4.2 "InsertDTMF":
> >
> >     When InsertDTMF is called, do the following:
> >
> >     1. If the associated MediaStreamTrack is not connected to the
> > associated PeerConnection, return.
> >     2. If canInsertDTMF is false, return.
> >     3. Set the value of the tone buffer to the "tones" argument.
> >         Return, but continue the following steps asynchronously.
> >
> >     The following steps take place asynchronously.
> >     4. Start playout of the tone on the associated RTP media stream,
> > using the appropriate codec.
> >     5. Fire a "tonechange" event at the object, with an event parameter
> > consisting of the first character
> >     of the tone buffer. Remove the first character of the tone buffer.
> >     6. If the tone buffer is empty, fire a "tonechange" event at the
> > object, with an empty string as
> >         its parameter, and stop.
> >     7. Schedule a task for <duration> milliseconds later, which will
> > repeat steps 4-7.
> 
> Should not all the above be moved to some other section (it is not a
> MediaStreamTrack any more)?


Support this, we may have a new section called Peer-to-Peer DTMF API after Peer-to-Peer Data API.

> 
> >
> >
> > Wordsmithing is of course needed.
> >
> >>
> >>
> >> - In section 4.3.2, add the function
> >>
> >> RTCDTMFSendingMediaStreamTrack
> createDTMFSender(MediaStreamTrack track);
> >>
> >> - In section 4.3.2.2, add the paragraph
> >>
> >> createDTMFSender
> >>
> >> The createDTMFSender() creates an RTCDTMFSendingMediaStreamTrack
> that
> 
> s/RTCDTMFSendingMediaStreamTrack/RTCDTMFSender/
> 
> >> references the given MediaStreamTrack. The MediaStreamTrack MUST be
> an
> >> element of a MediaStream that's currently in the PC's localStreams
> >> attribute; if not, throw an Illegal Argument Exception. [NOTE - get
> >> correct name for exception before inserting]
> >>
> >
> >
> 



Yang
Huawei
Received on Tuesday, 20 November 2012 01:54:31 GMT

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