RE: WWDM 2009

From: David Glaude [mailto:email@hidden]
Sent: Wednesday, June 17, 2009 10:37 PM
To: email@hidden List
Cc: Mark F. Murphy; Stas Oskin
Subject: Re: WWDM 2009

This is a repost because my first attempt was too long for the list (because of the quote):

First a big thanks to Mark for finding and sharing this "Informational" "Internet-Draft" edited by "Roger Pantos" from Apple Inc.

What the doc say is "Media data can be transmitted soon after it is created, allowing it to be received in near real-time".

It is basically a playlist (M3U) with "hint as extended comment" that indicate where to jump to when someone try to seek.

Your encoder must produce small files MPEG 2 TS or PS or audio elementary stream.

By small file they talk about 10s per file as a typical value.

Then you must produce those playlist file (easy for VOD) but for live they have the option of a sliding window playlist (let's say a playlist that is dynamicaly updated with the next chunk as they appear.

So all in all it might be possible to do a continuous streaming of a live event in Near Real Time.

This draft recommend to have always 3 chunk available at any given time and to start playing anywhere except on the last and second-to-last files.

If you use those value (10 s and 3 chunk) it make your viewer from 30s to 40s later than "Live" (not counting the time it take for your encoder to "upload" the next 10s chunk and "update" the playlist. So much for the Near Real Time. It is even possible to specify the Date and Time of the content so that the user can clearly see when it was shoot (as oppose to NOW).

Also, the document explain "Variant Playlist file" that look like Reference file where the best bandwidth can be choosen by the client.

So:

1) Should work with any HTTP server without any tricky module

2) Your encoder must produce chunk of encoded content
3) Your encoder must produce the play-list (and dynamicaly update it if you go for pseudo live)
4) There is no need for any DSS or anything like that

Is there someone out here that can give any good reason:
* to abandon 3GPP/MP4 file format
* to kill DSS/QTSS
* to return to MPEG2TS/PS where that should be limited to DVB-X and IP-TV system that just transport SAT/Terestrial/Cable content on IP

It seems that a new generation of Apple Eng is killing what other have build with RTP, RTSP, ... wich is the basic architecture for many thing such as VoIP, Visioconferencing, ...
WHY?

Now we need to upgrade/replace all of our encoder to produce compatible content and play-list where it would have been easyer for everyone to implement an RTP/RTSP client inside the iPhone.
Or maybe many will just giveup and forget about iPhone as a destination for their content.

Let's just hope android and other will not follow and stay in the standard track.

Is the iPhone penetration big enough to change the shape of "streaming"?

What do you think?

David GLAUDE