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[whatwg] Timestamp from video source in order to sync (e.g. expose OGG timestamp to javascript)

From: Nikita Eelen <neelen@amvonet.com>
Date: Mon, 17 May 2010 19:00:21 -0400
Message-ID: <D03AA749-2689-4AA7-AAFD-7021D0BBEC6E@amvonet.com>
I think he means something similar to what QuickTime broadcaster and quicktime streaming server does with a delay on a live stream or wowza media server with flash media encoder when using h.264, unless I am misunderstanding something. Is that correct Odin? Not sure how ice cast deals with it but I bet it's a similar issue,

Nikita

Sent from my iPad

On May 17, 2010, at 6:44 PM, David Singer <singer at apple.com> wrote:

> 
> On May 17, 2010, at 14:31 , Odin Omdal H?rthe wrote:
> 
>> Hello!
>> 
>> I filed bugs at mozilla and in chromium because I want to sync real
>> time data stream to live video. Some of them told me to send it here
>> as well. :-)
>> 
>> It's only possible to get relative playtime with html5 in javascript. I
>> want absolute timestamp that's embeded in OGG.
>> 
>> The spec only deals with relative times, and not getting out
>> information from the
>> 
>> Here's the deal:
>> I stream conferences using Ogg Theora+Vorbis using Icecast2. I have built a
>> site that shows the video and then automatically shows the slides (as PNG
>> files) as well. I use orbited (COMET) to have the server PUSH my ?next?
>> presses on my keyboard.
>> 
>> The problem is that icecast does heavy buffering, and also the client, so
>> that while I switch the slides, the browser will go from slide 3 to 4 WAY
>> too early (from 10 second to 1 minute).
> 
> Buffering should not make any difference to how far into a stream a time means.  If the transition from slide 3 to slide 4 happens at 10 minutes in, then as the presentation time ticks from 9:59 to 10:00 you should flip the slide.  It doesn't matter how much data is in any buffers, does it?
> 
>> 
>> If I could get the timestamp OR time-since-started-sending/recording from
>> the ogg file in javascript, I'd be able to sync everything.
>> 
>> There are multiple way to sync this, may even an stream with the slide-data
>> INSIDE the ogg file, however, AFAIK there's also no way of getting out such
>> arbitrary streams.
>> 
>> (PS: I had some problems, so sorry if you get this email many times! :-S)
>> 
>> --
>> Beste helsing,
>> Odin H?rthe Omdal <odin.omdal at gmail.com>
>> http://velmont.no
> 
> David Singer
> Multimedia and Software Standards, Apple Inc.
> 
Received on Monday, 17 May 2010 16:00:21 UTC

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