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Re: vodcasting

for

From: Andrew Kirkpatrick
Date: Nov 27, 2006 7:10PM


> and provide Closed Captioning in a SMIL layer for video on the Web.
>
> I can extrapolate to vodcasting as long as it's watched on the Web:
> provide Closed Captioning in a SMIL layer.

Not exactly, and certainly not universally.

SMIL isn't really a layer per se, the smil file is interpreted by the
player and the media presentation is assembled using the items
referenced by the smil. This works for Real players and is also used in
QT, but is not the only way to get captions in QT. WMP and Flash
operate differently.

> My question is: how about when it's being watched on a video
> iPod or similar device? Provide Open Captions in that case?

Open captions would work. The ipod can play the following:
1) H.264 video, up to 1.5 Mbps, 640 x 480, 30 frames per sec., Baseline
Low-Complexity Profile with AAC-LC audio up to 160 kbps, 48 Khz, stereo
audio in .m4v, .mp4, and .mov file formats
2) H.264 video, up to 768 kbps, 320 x 240, 30 frames per sec., Baseline
Profile up to Level 1.3 with AAC-LC audio up to 160 kbps, 48 Khz, stereo
audio in .m4v, .mp4, and .mov file formats
3) MPEG-4 video, up to 2.5 Mbps, 640 x 480, 30 frames per sec., Simple
Profile with AAC-LC audio up to 160 kbps, 48 Khz, stereo audio in .m4v,
.mp4, and .mov file formats

I haven't tested if smil is supported in the iPod, but I'm betting not.
Ask Apple to be sure.

There is also the possibility that there is a tool that can take a
smil/qt.txt/.mov combination and create a open captioned m4v, but I've
never heard of one yet.

> How to differentiate the files - watched on the Web w/SMIL
> vs. watched on iPod w/Open Captions? I don't have a video
> iPod or I'd try this

Another question is whether you serve up the same video file at all to
these different environments.

AWK