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RE: video aspect use case

From: Davy Van Deursen <davy.vandeursen@ugent.be>
Date: Wed, 9 Sep 2009 21:38:23 +0200
To: 'RaphaŽl Troncy' <Raphael.Troncy@cwi.nl>, 'Philip Jšgenstedt' <philipj@opera.com>
Cc: "'Yves Lafon'" <ylafon@w3.org>, <public-media-fragment@w3.org>
Message-ID: <000f01ca3185$19416d10$4bc44730$@vandeursen@ugent.be>
> > I've
> > only been able to understand it as forcing the aspect ratio of the
> > resource, rather than somehow modifying the resource (i.e. the exact
> > same bytes should be sent).
> 
> Well, not exactly. Converting formats of unequal ratios is done by
> either cropping the original image to the receiving format's aspect
> ratio (zooming), by adding horizontal mattes (letterboxing) or vertical
> mattes (pillarboxing) to retain the original format's aspect ratio, or
> by distorting the image to fill the receiving format's ratio. Depending
> on the strategy, if done on server side, the server will not serve the
> exact same bytes ... and possibly save some bandwidth (needs to be
> measured though!)

In my opinion, different aspect ratio's of a media resource are different
'versions' of one media resource and not different 'fragments'. You can
compare it with spatial scaling: as much as possible is done to preserve the
full content of the media resource. The latter is not the case with
fragments, where you select specific things of the media resource. So
shouldn't we just drop the aspect identifier?

Best regards,

Davy
Received on Wednesday, 9 September 2009 19:39:49 GMT

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