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Re: Reviewing the Web Audio API (from webrtc)

From: Robert O'Callahan <robert@ocallahan.org>
Date: Tue, 1 May 2012 18:45:17 +1200
Message-ID: <CAOp6jLb1SguXRp-tvJKJae4uio3nC7NWpKDa1g2LmHDvUsyZhg@mail.gmail.com>
To: Chris Rogers <crogers@google.com>
Cc: public-audio@w3.org
On Tue, May 1, 2012 at 10:53 AM, Chris Rogers <crogers@google.com> wrote:

> I'm guessing you're talking about a DVR-like scenario where you can pause
> a live video-stream from WebRTC?  In this case, it seems like it would make
> sense to have the pause() method be in the MediaStream API very similar to
> how we have a pause() method in HTMLMediaElement.  I'm not sure that the
> WebRTC group has considered that, but it seems like it could be a useful
> addition to their API.  If they add this method to MediaStream, then
> the "shifting a track forward in time" strategy I describe above could be
> used if the MediaStream has been paused, because the audio and video data
> will have been buffered/stored.


Yeah, you can restore synchronization, but what about the echoes having
been lost/dropped, since Web Audio cannot pause?

I also read this:
http://www.html5rocks.com/en/tutorials/webaudio/fieldrunners/
It seems that the ability to pause processed audio streams is intuitive for
authors, matches media elements, will match MediaStreams, and would be
useful.

If we do allow pausing a MediaStream, then we'll have to be careful to
> specify what the maximum pause time would be, since the pausing would
> presumably be implemented by buffering in memory for a short time, then
> recording to disk.  On my DVR at home, sometimes I pause live TV and forget
> about it (and go off to do something else around the house), then after
> about an hour the DVR automatically un-pauses the stream since it's
> buffered too much data to disk...
>

We already handle that for <video> elements reading from streaming sources.

Rob
-- 
“You have heard that it was said, ‘Love your neighbor and hate your enemy.’
But I tell you, love your enemies and pray for those who persecute you,
that you may be children of your Father in heaven. ... If you love those
who love you, what reward will you get? Are not even the tax collectors
doing that? And if you greet only your own people, what are you doing more
than others?" [Matthew 5:43-47]
Received on Tuesday, 1 May 2012 06:45:47 GMT

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