Re: [rtcweb] Text communication in RTCWEB sessions

[Gunnar Hellström <[e-mail]>]

On 2012-11-30 04:51, Randell Jesup wrote:
> Not so simply; MediaStreams in Firefox currently have a strong idea 
> that data has a time for display and a duration. This could be worked 
> around, and might need to for other reasons - but there was no design 
> goal for carrying non-media data in MediaStreams. 
Real-time text is to be seen as media. When using RFC 4103 for 
transport, the samples are usually 300 ms. Usually they should be played 
asap but smoothed out during the sampling period. If needed they can be 
synchronized through time stamps with other media. 3GPP TS 26.114 
Multimedia Telephony is a good example of a spec treating real-time text 
as any other media.

It is of course a good habit to keep already received real-time text 
visible for some time. I hope that that does not conflict with the time 
and duration idea. There is an expired draft telling how that can be done.
http://tools.ietf.org/html/draft-hellstrom-textpreview-08
That topic is also dealt with very briefly in the presentation standard 
ITU-T T.140 http://www.itu.int/rec/T-REC-T.140/en

/Gunnar