Why is movie jumpy when I play simultaneously in 2 Cocoa views?

Question

I have a Cocoa app that has two views. Both of these views are a subclass of QTMovieView. I want to play the same movie in both views (one view is a smaller preview of the larger view). Right now I'm doing:

QTMovie *movie = [[QTMovie alloc] initWithFile:path error:nil];  
[largeView setMovie:movie];  
[smallView setMovie:movie];

When I do this the movie is jumpy, it doesn't play smoothly. If I just set the movie to one or the other it seems to play just fine. I've tried multiple movies and they all do the same thing. Any ideas? Is there a better way to do this?

Answer 1

You are probably overtaxing a resource - CPU and/or disk I/O are your most likely culprits.

If you open two Quicktime windows can you play the movies at the same time without stuttering? Is your CPU maxed out (especially on a single-core machine)? Can you stream from a second source and fix the stuttering? You might try playing one of the movies off a USB hard drive or flash drive if you don't have two hard drives.

I'm not a quicktime or Objective-C programmer, but I'd start by looking at mirroring the content instead of opening two movie instances. Maybe you can capture a section of the screen, shrink the contents and dump it to a smaller preview window.