playing movies - basic question

1
Hello,

I am using psychophysics toolbox Version 2.54 on Windows platform to
play a movie of dynamic random dots with desired coherence of movement
and direction. Right now, I create random dot images for each frame of
the movie, load them into memory (using 'OpenOffscreenwindow') and
display them. If I use bigger images, it takes tens of seconds to load
the image into memory. This is too slow for our experiments. If I use
loop to load and display one image at a time, frames are missed. Is
there a faster way to play a movie of dynamic random dots or any
movie?

Thanks
Mani
2
Thanks for your suggestions Daniel. The 'DrawDots'and 'Flip'
commands work well and I could run random dot movie of any size at
refresh rate.

Cheers
Mani



--- In psychtoolbox@yahoogroups.com, "Daniel Shima"
<danielshima@...> wrote:
>
> In Psychtoolbox Version 3, there is DotDemo.m (i.e.,
> Psychtoolbox\PsychDemos\DotDemo.m) which uses the logic of the
> Screen('DrawDot') and Screen('Flip') commands among other instead
of
> the Version 2.54 logic of precomputed off-screen windows.
>
> Daniel Shima
> Vanderbilt Vision Research Center
>
>
> On 10/27/06, Pareen <manivannan33@...> wrote:
> > Hello,
> >
> > I am using psychophysics toolbox Version 2.54 on Windows
platform to
> > play a movie of dynamic random dots with desired coherence of
movement
> > and direction. Right now, I create random dot images for each
frame of
> > the movie, load them into memory (using 'OpenOffscreenwindow')
and
> > display them. If I use bigger images, it takes tens of seconds
to load
> > the image into memory. This is too slow for our experiments. If
I use
> > loop to load and display one image at a time, frames are missed.
Is
> > there a faster way to play a movie of dynamic random dots or any
> > movie?
> >
> > Thanks
> > Mani
> >
> >
> >
> >
> > Post your message to: psychtoolbox@yahoogroups.com
> > Please indicate OS9, OSX, or WIN version, and include your full
name.
> > Denis Pelli, David Brainard, and Allen Ingling.
> > http://psychtoolbox.org
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
>