Executing functions while playing movies

1
I am a new MatLab programmer attempting to write a
psychophysical test program. During this test, I have included
animations to acknowledge user response. I initially used the
SCREEN functions for animation and have started exploring the
use of QT movies as another option.

Aside from providing feedback, I was hoping to use the
animation as a pause in the program where I could execute a
very time demanding function that, if put elsewhere, slows the
trial process significantly. However, neither the SCREEN nor QT
animation options seem to provide this background execution.

Ideally I want the animation to proceed in the same way that the
SND function does, returning immediately to allow for the
continuation of the program while the sound is still being played.
If this is possible in any format I would greatly apprecitate the
assistance,

Thanks in advance,

Craig Chapman
2
>I am a new MatLab programmer attempting to write a
>psychophysical test program. During this test, I have included
>animations to acknowledge user response. I initially used the
>SCREEN functions for animation and have started exploring the
>use of QT movies as another option.
>
>Aside from providing feedback, I was hoping to use the
>animation as a pause in the program where I could execute a
>very time demanding function that, if put elsewhere, slows the
>trial process significantly. However, neither the SCREEN nor QT
>animation options seem to provide this background execution.
>
>Ideally I want the animation to proceed in the same way that the
>SND function does, returning immediately to allow for the
>continuation of the program while the sound is still being played.
>If this is possible in any format I would greatly apprecitate the
>assistance,
>
>Thanks in advance,
>
>Craig Chapman

dear craig

everything you say is right. and the wishes you express are shared by
others. Matlab doesn't do multitasking, so the SCREEN functions
cannot be spawned off as a background process. it's possible that
Quicktime can be set up as a background process, and that someone
could enhance QT.mex (renamed Showtime.mex in forthcoming release) to
do so.

what you can do, of course, is to write a program that does two
things at once by cleverly interleaving the tasks.

best

denis

p.s.
as you say, SND is an autonomous background process. this is possible
because Apple wrote this capability into their Sound Manager, and it
still took a large effort on our part to implement. Backgrounding is
cool, but hard. In theory this is what unix (including Mac OS X) is
supposed to make easy, but i don't know how much we'll benefit from
within Matlab.