QuickTime and AVI on Same CD

Date:    Tue, 14 Nov 1995 11:26:36 EST
From:    John Dowdell <71333.42@COMPUSERVE.COM>
Subject: Re: AVI and QT

Kathleen Dolan writes on Nov 13, "We are creating a cross platform CD-rom. We have decided to use Quicktime movies for the mac and AVI movies for windows version. The plan is to have one content file and media folder shared by the mac projector and the windows projector. I had planned on testing for machine type at the start and saving that information into a global variable that determines which set of movies to play, probably by switching castmembers. I've run into a glitch. I'm authoring on the mac, and when I try to import the AVI files, I get an error - "having trouble reading the file". Is there anyway around this? I'm assuming I need to have the pointers to the avi files in the cast to play the movie, or is there a way to import these on the fly, once the machine type has been determined to be a PC?"

Yes, it's a bit of extra work to run twin media. There's a technique which could save tremendously on work here, however. First, though, the standard disclaimer:

"It's easiest to manage linked media if it's local to the movie that calls it. This does not imply that your total title is in one big directory, because you can more easily traverse the directory tree with 'go to movie' commands than you can reset links. If external media is local then it's easier to manage."

(whew... worked my jones out there.... ;)

Check the Lingo "searchPath" function, Kathleen. If you have the early version of the Lingo Dictionary, where it says that this is a read-only property, note that this error was corrected in the ReadMe file for that version... you can both get and set this property. It functions like the DOS PATH description.

In the movie within your Projector, try something like:

  --  Warning: Single-coffeecup Lingo! <g>
  on startMovie
    if the machineType = 256 then set vidpath to "@:media:avi"
    else set vidpath to "@:media:mov"
    add the searchPath, vidPath
  end startMovie

Subsequent movies will then search for linked files in the directory you specify. If the two sets of video assets share the same names, then this should give the results you desire.

Notes:

Be sure to set this property before you enter a movie where you'll need it... just as with the PATH statement, it needs to be set up and established before it's used.
I'm groggy this morning on the extension, apologies... would recommend testing whether Director can resolve the links regardless of extension. Some times in the past we've needed the correct extension to bring up the appropriate AVI or QTW DLLs, but regret that I don't recall offhand this morning whether it would be necessary here.
When linking to distant files like this, be sure to Projectorize and/or protect movies into the same directory in which the raw movies lie. This is because Director sets up relative paths when protecting the movies... Projectorizing into a different directory could break the distant links.
Use of the platform-independent relative-pathname specifier "@" above is discussed on pp 53-4 of the "Tips & Tricks" manual. Can use colons or slashes; will convert. This is for use *internal* to Director, for links and "go to movie" commands, but is not understand by FileIO, "open" command and other such external evaluations.
If you are not using any other linked files then you could falsify the "searchCurrentFolder" property to speed up searching. Keep the searched directories to a minimum, or else you're wading through tons of files.
As with all directory management, the more files in a folder the slower it will be, and there is an upper limit on the number of files in a folder before problems start. (700 on Mac...?)
CD access is faster when linked files are local to the movie, too. If you're playing a movie in one section of the disc, and then have to go 'way off to another section to retrieve some linked files, and then come back to the original section for more stuff in the movie, then that will be slower than if the CD never has to change its speed.

Hope the above's of use, and of interest.... ;)