Re: [rtcweb] No Plan

Iñaki Baz Castillo <> Mon, 03 June 2013 21:25 UTC

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From: =?UTF-8?Q?I=C3=B1aki_Baz_Castillo?= <>
Date: Mon, 3 Jun 2013 23:20:12 +0200
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To: Paul Kyzivat <>
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Subject: Re: [rtcweb] No Plan
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2013/6/3 Paul Kyzivat <>du>:

> One answer may be that the difference is that the real-time requirements for
> text aren't as demanding as they are for voice or video. But there are other
> good reasons for identifying interactive text as media. One reason is what
> we are arguing right how: the desire to negotiate properties of the
> transmission. (Should it be byte-by-byte or line-by-line.) Another is that,
> like voice and video there is likely to be a demand to record it for later
> analysis and playback, or to broadcast it to a collection of people.
> When text is treated as media, then treating it in parallel with other media
> makes more sense. (For instance ensuring the that the text is synchronized
> with the other media, both initially and when recorded and played back
> later.)

Well, I must recognize that now I see a real usecase: realtime
subtitles synchronized with audio/video streams. That would be much
better than the typicall subtitles embed in the video stream (because
it could be rendered as real text, so the user could choose the text
size, and so on).

Problems of standarizing text over RTP:

- Encoding

- ¿just plain text? ¿could it be HTML code instead? ¿how to send
hyperlinks? ¿how to use custom markup?

- Integrity: RTP can loose packets, do we accept that a chat can loose
"chars" or "lines"?

Iñaki Baz Castillo