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Re: Tech Discussions on the Multitrack Media (issue-152)

From: David Singer <singer@apple.com>
Date: Thu, 24 Feb 2011 17:36:43 -0800
Cc: Bob Lund <B.Lund@cablelabs.com>, "public-html@w3.org" <public-html@w3.org>
Message-Id: <BE45BC6C-3ABF-40CA-AF81-E777428C1709@apple.com>
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>

On Feb 24, 2011, at 17:29 , Silvia Pfeiffer wrote:

> When you talk about videos that are slide shows, are you actually
> talking about videos or about a sequence of images (photos) that are
> also sparse along the timeline, so not really "moving images"? If they
> are encoded as video, it would be impossible to distinguish the data
> as a sequence of photos. The other case - basically an "image track"
> is not something we've ever discussed before and is not something that
> all containers have formats for FAIK.

I mean a video track where the frame rate is like 1 frame every 10 seconds.  Many, or even most, containers can express this, I think.

> As for chapter images - I am not sure how they are encoded in
> QuickTime/MPEG, so if you know, please share. I would have thought
> that a text track with image urls could be sufficient for this.

An obvious choice is as above, using an I-frame-only coding (e.g. JPEG).

David Singer
Multimedia and Software Standards, Apple Inc.
Received on Friday, 25 February 2011 01:37:45 UTC

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