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Re: Feedback on the recording proposal

From: Robert O'Callahan <robert@ocallahan.org>
Date: Wed, 10 Oct 2012 11:22:58 +1300
Message-ID: <CAOp6jLaiYfdC2QaaYA08HPj-u_s4eWChXv3CPYKNAJF-qwdGmg@mail.gmail.com>
To: Jim Barnett <Jim.Barnett@genesyslab.com>
Cc: Adam Bergkvist <adam.bergkvist@ericsson.com>, public-media-capture@w3.org
On Wed, Oct 10, 2012 at 2:13 AM, Jim Barnett <Jim.Barnett@genesyslab.com>wrote:

> Comments on a couple of issues:****
>
> **1.       **The current draft states that stopRecording fires after the
> final dataavailable event, precisely so that it can serve as a signal that
> the app won’t be receiving any more packets.
>

Ah, great.


> ****
>
> 2.       (This is in response to Robert’s suggestion that if we want to
> capture a single Track, we put it in its own MediaStream.)  Consider the
> case where we want to record audio and video into separate captures/files
> (so that we can run media processing on them individually) but will later
> want to play them back synchronized. Hence we need to store some sort of
> ‘marker’ with each capture  that can be used for alignment.
>

I would hope that the start of the recorded tracks would be an acceptable
synchronization point...

Since synchronization occurs at the MediaStream level, wouldn’t we have to
> capture the underlying  Tracks from the same MediaStream so that the data
> is synchronized as we capture it?  Or is it the case that if we put Track1
> and Track2 together in MediaStream1, and then place them separately in
> MediaStream2 and MediaStream3,  they will be synchronized as they are
> played in Stream2 and Stream3?  The spec doesn’t state how synchronization
> occurs, so I, at least, have had trouble figuring out issues like this.
>

Yeah, I don't think that's specified right now. In Gecko all the streams
that share tracks would be synchronized, though.

Rob
-- 
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Received on Tuesday, 9 October 2012 22:23:29 GMT

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