strange behavior of saveMovieFrames ->quicktime on OSX, and a workaround

[Alex Holcombe]

The line:
myWin.saveMovieFrames('myMovie.mov')
in the captureFrames.py demo file will create a quicktime movie of
your display, and psychopy reports no errors in doing so.

However, on my machines (OSX 10.6, MacBook Pros) at least, this
success is short-lived. If I open the movie file immediately, it
opens and plays fine.
However, sometimes if I open it later (perhaps after rebooting the
machine), or transfer it to another machine, the movie will either no
longer open or will play very strangely. When it doesn't open, I
eventually get the message:

"A necessary data reference could not be resolved"

I don't think this problem is specific to 1.63, but it might be. I am
aware that Quicktime allows for external references to data rather
than storing all the images within the file, and I wonder if somehow
the images are not getting saved into the single file container. This
vague idea is supported by the observations that: 1) When the file
stops working, the Finder shows that it has shrunk in size from
several megabytes, to just 8 kilobytes
2) the following workaround works. If you open the movie (before it
stops working) with Quicktime Player (I am using version 10.0), and
File->Save As->Format:Movie to a new file, that file will always work
(so far).