W3C home > Mailing lists > Public > public-device-apis@w3.org > September 2010

Re: CfC: The Media Capture API FPWD

From: Ilkka Oksanen <Ilkka.Oksanen@nokia.com>
Date: Tue, 21 Sep 2010 15:57:09 +0300
Message-ID: <4C98ABA5.5030201@nokia.com>
To: ext Philip Gladstone <pgladstone@cisco.com>
CC: "public-device-apis@w3.org" <public-device-apis@w3.org>
Hi Philip,

Thanks for you comments.

03/09/2010 17:45, ext Philip Gladstone kirjoitti:
> * The current draft does not appear to permit the web app to choose 
> which camera to use -- presumably this will be a choice presented to
> the user when the camera app is started. Is this intentional? For
> example, I have a four port video capture device. I would like to be
> able to say 'capture picture on each device in turn, and send the
> results to my server, forever'. Once I have provided the permission
> to do that, it ought to do that. However, I can't choose the input
> port, and I can't say 'automatically take picture' (unless this is an
> option of the camera app).

This is currently left to the camera apps.

> * It is unclear (to me) whether the MediaFile that is returned when
> a capture completes is persistent or not. Also, the handling of it
> will be rather different if it is a data: url. The issue here is what
> happens if the web app loses the MediaFile. Does the underlying image
> continue to exist (potentially consuming space on a memory card)? Can
> these MediaFile references be recovered in a later session?

Lifetime of the captured files was unspecified. I think storage area for
the files should work like a HTML5 local store. My solution was therefore
to bound lifetime of the files to top-level browsing context.

> * Is the cancel on the PendingOperation synchronous? I.e. once that 
> method returns, has the PendingOperation been cancelled, or is it
> only canceled when (for example) the errorCB is called with a
> 'CANCELED' error status. If an image capture is cancelled once the
> user has captured one image, is that image lost, or does it get
> returned on a successCB? If it is lost, does it remain in persistent
> storage?

New version of the draft specifies that no callbacks are invoked and
all the possible captured files are deleted.

Received on Tuesday, 21 September 2010 12:57:51 UTC

This archive was generated by hypermail 2.3.1 : Monday, 23 October 2017 14:53:46 UTC