Date: Sat, 20 May 1995 19:32:11 -0700 From: Alex Zavatone <azavatone@MACROMEDIA.COM> Subject: **WARNING** QT to AVIThis is for the folks interested in the QTtoAVI utility for converting Quicktimes to AVIs. The quicktimes becomed packaged in an AVI 'wrapper'. On the mac, the movie plays as a quicktime, on the pc, it plays as an avi. On the mac, it leaks memory. As of my last check in December, movies that looped and were quicktimes converted to AVI with the converter did not purge memory properly on the mac. Your mac may run out of memory in 15 minutes, or 4 hours. This leads to crashes. Not good.
"Ok, Alex if you're so smart how do I tell if my movie is leaking memory?"
Well, memory can leak into different areas, the application heap, the system heap, etc. There are several ways to check out if memory is leaking in your application heap. The easiest is to create the avi wrapped quicktime and open it in movie player. Set the movie to loop. In the Finder, turn on balloon help and choose about this Macintosh. When you move the mouse over each application's partition, the free memory is displayed in the balloon help window. Record this number. Turn off Balloon help for the moment. Move the 'about this mac' window so you can see it when the movie is playing in movieplayer. Switch back to movieplayer, positon the arrow cursor over the end of the used memory in the about this mac and play the movie by pressing the space bar. Go to lunch, go home or just leave the computer alone for several hours. When you come back, check the memory partition of movieplayer. Is almost all the memory used up? What does balloonhelp say? Ususally, when a quicktime plays, some memory is allocated and then disposed when it is not needed. What I have noticed with AVI wrapped Quicktimes is that memmory will be allocated until the entire partition is FULL. This is just bad for use within director. If you verify that the wrapped Quicktimes play with memory the same way that regular quicktimes do, then I would feel safe using them. If they are behaving as described, then I strongly recommend against using them.
Alex Zavatone
Director Engineering
Macromedia
AZavatone@Macromedia.com