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Re: recording proposal

From: Adam Bergkvist <adam.bergkvist@ericsson.com>
Date: Tue, 9 Oct 2012 12:00:25 +0200
Message-ID: <5073F5B9.2090100@ericsson.com>
To: Jim Barnett <Jim.Barnett@genesyslab.com>
CC: "public-media-capture@w3.org" <public-media-capture@w3.org>
On 2012-10-05 15:55, Jim Barnett wrote:
> Here is a proposal for recording for discussion on Tuesday’s call.
> -Jim and Travis

Thanks for putting together this proposal. Some comments inline.

> requestData
> This method is a request for the UA to generate a dataavailable event
> containing the data that it has currently gathered. This method thus
> allows the application to poll for data according to its own
> schedule. When this method is called, if recording is true, the UA
> must raise a dataavailable event containing its current Blob of data
> and then start collecting a new Blob. If recording is false, this
> method is a no-op.

I think this is a nice feature.

> dataavailable    MediaStreamEvent
> The UA returns data to the application. This event contains a Blob of
> recorded data.

> various errors TBD    MediaStreamEvent

Any particular reason why these are MediaStreamEvents (which carry a 
MediaStream payload)? I think we have two options with the 
"dataavailable" event:

1) Use a simple event that indicates that a data attribute of type Blob 
is ready to be read.
2) Introduce a new event interface with a Blob payload.

Perhaps option 2 is the only reasonable one since we want to support 
sliced recordings which produces several Blobs and it doesn't work well 
with a single Blob attribute.

> 1.6 Open issues

> 2. Should recording be moved into a separate class?

I'm leaning towards that.

> 4.  What are the privacy implications of recording? Does the
> application need to request special permission?

I think we should treat recording and rendering video on a canvas and 
extracting pixel data as equal in terms of privacy. So if the first can 
be done without extra permissions then recording should be allowed too.

Received on Tuesday, 9 October 2012 10:00:56 UTC

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