Some DTMF Questions

[aboba]

From Shijun Sun:

1. What happens if a DTMFSender object sender is constructed from an RTCRtpSender object sendObject and methods such as insertDTMF() are called, but sendObject.send() was not previously called to set up the DTMF codec?

var sendObject = new RTCRtpSender(audioTrack, dtlsTransport);
var sender = new RTCDtmfSender(sendObject);
if (sender.canInsertDTMF) {
var duration = 500;
sender.insertDTMF("1234", duration);
} else
log("DTMF function not available");

In the above example (assuming the DTMF function is available) does sender.insertDTMF() throw an InvalidState exception?

1. In the single sender example above, what happens to the audioTrack when DTMF is being sent? Presumably the audioTrack is not encoded, correct? Then once the DTMF tones are played out, audioTrack is encoded and sent over the wire within RTP packets again?

[aboba]

The proposed resolution is to add the following text to Section 10.3.2:

insertDTMF
Insert DTMF tones. Since DTMF tones cannot be sent without configuring the DTMF codec, if insertDTMF() is called prior to sender.send(), throw an InvalidStateError exception.

[aboba]

A slight revision:
insertDTMF
Insert DTMF tones. Since DTMF tones cannot be sent without configuring the DTMF codec, if insertDTMF() is called prior to sender.send(parameters), or if sender.send(parameters) was called but parameters did not include the DTMF codec, throw an InvalidStateError exception.