Hi,

we're considering a SMIL-based solution for stand-alone multimedia-presentations (i.e. digital signage) in our organisation, but are not sure how well it fits our needs with regards to integrating calendar time range specific content into the "normal flow" of a seq/par-driven presentation.

We'd be very grateful if some more SMIL-experienced people would comment on the following two scenarios:

__Scenario 1:__

Consider a presentation of the following form that continually loops through a number of multimedia pages:

<seq repeatCount="indefinite">
    <ref title="Page 1"/>
    <par>
        <ref title="Page 2"/>
        <ref title="specialOverlay"/>
    </par>
    <ref title="Page 3"/>
    <ref title="Page 4"/>
    ...
</seq>

Now, is it possible to add SMIL markup to this presentation that will enforce the following constraints, respectively:

   example A)  Only show the "specialOverlay" on [Sunday, 30. Mai 2010, 9am - 18am] (or any other specific calendar time range)
   example B)  Only show the "specialOverlay" on [Sunday, between 9am - 18am] (meaning: *every* sunday)
   example C)  Only show the "specialOverlay" on holidays (where the data about which days are holidays is supplied through an external file)

..without otherwise affecting the behaviour of the seq element?

__Scenario 2:__

Consider again a presentation continually looping through a fixed set of pages:

<seq repeatCount="indefinite">
    <ref title="Page 1"/>
    <ref title="Page 2"/>
    <ref title="Page 3"/>
    ...
</seq>

Imagine this presentation will run around-the-clock, all year long.
Now, is it possible to specify an alternative <seq></seq> section for a specific calendar time range so that at the beginning of this time range, the normal seq presentation is halted (no matter what it's currently showing), and the alternative <seq></seq> is shown, until the end of the time range, when the normal presentation is resumed? (Note: it would also be acceptable if the original presentation would then re-start at its beginning, instead of resuming exactly where it had left off.)

Is this kind of stuff possible with SMIL 3.0 markup?

Note that we *don't* want to use scripting, just XML-based markup (if this is not possible with plain SMIL, we'd rather develop a custom non-SMIL-based solution altogether, or our own SMIL-extension, or a "wrapper" that calls/terminates different SMIL presentation at different times).

We appreciate any help/advice!