Re: why SMILtext preamble?
http://lists.apple.com/archives/quicktime-users/2006/Nov/msg00129.html
* Subject: Re: why SMILtext preamble?
* From: Eric Carlson <email@hidden>
* Date: Sat, 18 Nov 2006 18:14:59 -0800
* Delivered-to: email@hidden
* Delivered-to: email@hidden
On Nov 18, 2006, at 11:40 AM, Lucas Gonze wrote:
I have always wondered why Quicktime SMIL likes to have the normal XML
file preamble ("<?xml ...>") replaced with a proprietary marker
("SMILtext"). The only impact of this as far as I can figure out is
to ensure that SMIL for Quicktime doesn't work in other SMIL
renderers.
Is it just to prevent interoperability?
No. The only reason to put "SMILtext" at the beginning of a SMIL file is so you can give it an .mov extension. A SMIL file is a text file, not a QuickTime movie, but putting "SMILtext" as the first eight bytes tells QuickTime how to open it (to use the SMIL movie importer).
You would only use this technique when you want to guarantee that the QuickTime plug-in will be used to open a SMIL file in an EMBED in a web page. QuickTime will happily open a SMIL file without the "SMILtext" prefix as long as it has a .smi or .smil extension, but if you put such a file in an EMBED you have not control of which plug-in will be chosen by the browser to open it.
Eric Carlson
QuickTime Engineering