Movie with a mask?

[Scott Rossi]

>> If you don't have a lot of frames ('a lot' is a relative term) you could use
>> a series of PNG images which are masked as needed and swap them in sequence
>> in a button object.
> 
> Wow! I hadn't thought of that - the big problem there would seem to be
> speed (I am worried that some of my users - schools in the UK, chronically
> short of money - may have very slow machines). But I am keen to try it.

Unless you're talking truly old machines or 640x480 sized images, I tjink
you'll find the speed to be very acceptable.


>> As previously suggested animatedGIF or PNG.
>> 
>> Or, if the background upon which your movie is lain will always be the same,
>> just use an old trick - composite that backgroud right into your movie then
>> run it in an exactly-positioned rect - no mask needed.
> 
> Yes, I can manipulate the design of my app to make this possible, so I
> guess that would be the way to go - but as I'm still worried about the
> performance hit, I'll probably try one of the other solutions.
> 
> The hidden problem for me in using the other solutions suggested is that I
> want to be able to run the movies forwards or backwards with different
> speeds and always with sync sound (so that the slow speed movies would have
> a deeper, slower sound for example). This is a no-brainer in QT, but for
> every other method (AFAIK) one is just stuck having a whole set of 'movies'
> called, e.g.
> 
> slowest, very slow, slow, normal, fast, very fast, fastest - with
> appropriate sound tracks.

As you noted, a movie format is certainly going to be a lot easier for you
to manage than frame-by-frame animation or trying to synch up audio with an
animated GIF.  Synching sound with frame-by-frame animations is possible,
but it's more work:

  if the icon of btn myButton = id of img frame1.png then play mySound

It sounds like you need to prioritize your requirements:

- If the key aspect of your project is carefully synched animations and
audio then you should probably go with QuickTime (and/or additional movie
formats) and design your stacks around the QuickTime media.

- If the key aspect of your project is masked animation and sound is less
critical then frame-by-frame animation could work.

Regards,

Scott Rossi
Creative Director

Tactile Media, Multimedia & Design
Email: scott at tactilemedia.com
Web: www.tactilemedia.com