[RTW] List is now open

Justin Uberti juberti at google.com
Mon Oct 11 06:19:55 CEST 2010


On Sun, Oct 10, 2010 at 5:44 PM, Silvia Pfeiffer
<silviapfeiffer1 at gmail.com>wrote:

> It seems to me that works nicely for 1-to-1 RTC. It wouldn't even require
> introduction of RTP/RTSP but can simply be pushing encoded a/v packets over
> the network as fast as possible on the given URL, which would then be a UDP
> URL?
>

The URLs I refer to are really just identifiers to identify resources
internally inside the browser - for the network connectivity the plan is to
use ICE to interactively determine how packets should be routed to the
desired endpoint in the presence of NATs and firewalls.

Regarding RTP, we'll want to use RTP for the on-the-wire protocol, so that
we get all the goodness of RTP - multiplexing multiple streams and/or
formats, detection of losses, lipsync, etc.


> I guess for multi-peer RTC a different approach on the network would be
> required or would it be a full mesh?
>

Conferencing is a key use case, and I think this design can support either
centralized or distributed conferencing models. The nodes will connect to
one another using the same wire protocol, but the overall topology of the
nodes will be up to the application.


> Silvia.
>
>
> On Mon, Oct 11, 2010 at 10:43 AM, Justin Uberti <juberti at google.com>wrote:
>
>> My idea is that we will tie these various pieces together like a filter
>> chain, i.e.
>>
>>  <device> -> [encoder] -> [transport] -> [decoder] -> <video>
>>
>> where the connections between pieces are made by passing URLs around.
>> (i.e. opening a device yields a URL for a stream, which is supplied to the
>> encoder; at the other end, streams coming from the decoder are identified by
>> a URL, which can then be passed directly to a <video> tag or WebGL texture.)
>>
>> Other combinations are of course possible, such as direct access to
>> [transport], in the case of a web real-time game, or combining <device> ->
>> encoder -> websocket, for doing live (non-realtime) broadcasts.
>>
>> We're still figuring out the right interfaces for encoder/decoder; for
>> transport, hopefully the draft I proposed<https://docs.google.com/viewer?url=http://rtc-web.alvestrand.com/papers/juberti-p2ptransport-api.pdf%3Fattredirects%3D0>can serve as a reasonable starting point.
>>
>> --justin
>>
>>
>> On Sun, Oct 10, 2010 at 4:26 PM, Stefan Håkansson LK <
>> stefan.lk.hakansson at ericsson.com> wrote:
>>
>>>  That's right, a lot of things remain regarding protocols and other
>>> stuff. But IMHO <device>, StreamAPIs and <audio> and <video> should be part
>>> of the puzzle!
>>>
>>> --Stefan
>>>
>>>  ------------------------------
>>> *From:* Silvia Pfeiffer [mailto:silviapfeiffer1 at gmail.com]
>>> *Sent:* den 11 oktober 2010 01:23
>>> *To:* Stefan Håkansson LK
>>> *Cc:* Harald Alvestrand; rtc-web at alvestrand.no; David Singer
>>>
>>> *Subject:* Re: [RTW] List is now open
>>>
>>> Hi Stefan,
>>>
>>> I have seen those, thanks. That's actually the reason why I asked:
>>> because I have already seen it work with the <device> element and I wondered
>>> what the remaining challenges were. It seems there is lots of discussion
>>> about protocols and codecs.
>>>
>>> Cheers,
>>> Silvia.
>>>
>>>
>>> On Mon, Oct 11, 2010 at 9:49 AM, Stefan Håkansson LK <
>>> stefan.lk.hakansson at ericsson.com> wrote:
>>>
>>>>  Silvia,
>>>>
>>>> you might be interested in some experimenting we've done with media
>>>> streams and <device>:
>>>> https://labs.ericsson.com/developer-community/blog/beyond-html5-conversational-voice-and-video-implemented-webkit-gtk (you
>>>> can track back to earlier posts).
>>>>
>>>> BR,
>>>> Stefan
>>>>
>>>>  ------------------------------
>>>> *From:* rtc-web-bounces at alvestrand.no [mailto:
>>>> rtc-web-bounces at alvestrand.no] *On Behalf Of *Harald Alvestrand
>>>> *Sent:* den 9 oktober 2010 10:12
>>>> *To:* Silvia Pfeiffer
>>>> *Cc:* rtc-web at alvestrand.no; David Singer
>>>> *Subject:* Re: [RTW] List is now open
>>>>
>>>>   On 10/09/10 03:17, Silvia Pfeiffer wrote:
>>>>
>>>> Thanks for the general invite!
>>>>
>>>> I wonder: has the HTML5 device element been looked at (
>>>> http://dev.w3.org/html5/html-device/) and what are the problems with
>>>> that solution?
>>>>
>>>> We're the ones who have to look - and some on the list have been closely
>>>> involved with writing the <device> spec. It would be surprising to me if
>>>> they are not part of the solution - but just part.
>>>>
>>>> As far as I know, it's still not clear how to tie a <device> to a media
>>>> stream - given that media streams aren't defined yet, this is not very
>>>> surprising :-)
>>>>
>>>>
>>>> Cheers,
>>>> Silvia.
>>>>
>>>>
>>>> On Sat, Oct 9, 2010 at 5:28 PM, David Singer <singer at apple.com> wrote:
>>>>
>>>>> Cool, thanks Harald
>>>>>
>>>>> as I said during the day, I'd like to separate (as much as possible)
>>>>> "why is real-time communications on the internet hard?" (which is true, but
>>>>> a subject the IETF, the ITU, and others are also grappling with) from "what
>>>>> is interesting/challenging about real-time communications *in the web*?" --
>>>>> which I take to mean in pages shown by a browser.
>>>>>
>>>>>
>>>>> On Oct 8, 2010, at 4:24 , Harald Alvestrand wrote:
>>>>>
>>>>> > Cullen (I think) has changed the permissions on the list, so that now
>>>>> everyone can subscribe, and the archives are open.
>>>>> >
>>>>> > If you know of people you think should be on the list, please ask
>>>>> them to subscribe!
>>>>> >
>>>>> > The two ways to subscribe:
>>>>> >
>>>>> > - Send "subscribe" to rtc-web-request at alvestrand.no, and do what the
>>>>> response says
>>>>> > - Go to http://www.alvestrand.no/mailman/listinfo/rtc-web and follow
>>>>> instructions
>>>>> >
>>>>> > Let the discussions begin!
>>>>> >
>>>>> >             Harald
>>>>> >
>>>>> > _______________________________________________
>>>>> > RTC-Web mailing list
>>>>> > RTC-Web at alvestrand.no
>>>>> > http://www.alvestrand.no/mailman/listinfo/rtc-web
>>>>>
>>>>> David Singer
>>>>> Multimedia and Software Standards, Apple Inc.
>>>>>
>>>>> _______________________________________________
>>>>> RTC-Web mailing list
>>>>> RTC-Web at alvestrand.no
>>>>> http://www.alvestrand.no/mailman/listinfo/rtc-web
>>>>>
>>>>
>>>>
>>>>
>>>
>>> _______________________________________________
>>> RTC-Web mailing list
>>> RTC-Web at alvestrand.no
>>> http://www.alvestrand.no/mailman/listinfo/rtc-web
>>>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.alvestrand.no/pipermail/rtc-web/attachments/20101010/d1845c51/attachment.html>


More information about the RTC-Web mailing list