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Re: Systematic access to media/plugin metadata

From: Danny Ayers <danny.ayers@gmail.com>
Date: Tue, 12 Apr 2011 22:14:16 +0200
Message-ID: <BANLkTinFiroTcFO8DXa9NV4SvRuziAj+TA@mail.gmail.com>
To: Laura Carlson <laura.lee.carlson@gmail.com>
Cc: Eric Carlson <eric.carlson@apple.com>, Henri Sivonen <hsivonen@iki.fi>, Silvia Pfeiffer <silviapfeiffer1@gmail.com>, "public-html@w3.org" <public-html@w3.org>
A couple of observations in passing.

At least in the case of audio & video media elements, some access to
metadata is already supported in the spec. However, from a developer's
point of view it seems somewhat convoluted, and arbitrarily limited.
For example, let's say the media object has embedded copyright
information. If I understand correctly, accessing such information
would involve steps including -

* obtaining the text tracks and selecting those of kind "metadata"
* processing the discovered material according to the specification of
the media object

I suppose the first part isn't a huge amount of work, but I would
posit that it'll involve a few more lines of code than accessing, say,

But the second part is something of a blocker, decoding the metadata
is left to the developer - irrespective of whether or not the
browser/media plugin has access to the content. (I'm by means
suggesting that browsers should support every kind of metadata
encoding, just suggesting that it's possible that in many cases such
support is already available internally, but with the way the spec
currently stands, unavailable to the developer). By the same token,
might it not be reasonable to access an image's embedded metadata (if
available) through a call like: image.getMetadata("license")?

The other thing that came to mind, after looking at the page Laura's
posted [1] is that there are two general groups of metadata detail
potentially available: material that corresponds to some kind of
alternate representation, such as alt="text" and transcript kind of
things; material that describes other features of the resource, e.g.
timestamp and geo coords embedded in Exif in a photo. Not sure of the
value of this observation, beyond maybe it suggests two varieties of
use cases.


[1] http://www.w3.org/html/wg/wiki/Metadata

Received on Tuesday, 12 April 2011 20:14:43 UTC

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