Re: TTML and aspect ratio

On Wed, Jan 30, 2013 at 8:57 AM, David Ronca <dronca@netflix.com> wrote:

> > Today, when dealing with 608 and 708 sourced content, one should rely on
> the
> > SMPTE work.  Except for 2052-11, which is not yet published, the work is
> > available for free at www.smpte.org.
>
> We ingest captions from many different formats besides 608 & 708, and thus
> need a general way to resolve this issue.  The most obvious being <tt
> tts:aspectRatio>.


That's not at all obvious to me. Firstly, why would this be different that
<tt tts:extent>? You say you contract out captioning and receive back TTML
that contain <tt tts:extent='320px 240px'>, is that correct? So this is
4:3, yes? What would it mean if you had <tt tts:extent='320px 240px' and
ttp:displayAspectRatio='16 9'>?

If you are dynamically generating different media streams to satisfy
different clients, why don't you dynamically transform a master TTML
document into a display specific document that is targeted to work with the
media stream format?