Forums > Jitter

Direct to window bug report

Feb 22 2006 | 12:05 pm

I am experiencing a bug when using the direct to window feature of in cooperation with the rect message to a jit.window. When I
reposition the window and a movie is already playing (direct to window) the
output on the window stops. This also occurs when a window has been
positioned via the rect message- sending visisble 0 and then visisble 1 to
the window. The output has stopped.

Workaround: sending a bang to the object. Sending a frame
message does not solve the problem.

Mac OS 10.4.4, qt 7.04, Max/Msp 4.5.6 Jitter 1.5.2
12" Powerbook, 1.5 GHz, GeForce FX Go5200

Thanks. John.

Feb 22 2006 | 12:18 pm

This seems like a usage problem to me, if I’m reading your mail
properly. Sending a bang to is the documented method for
getting a frame to be shown in the interface. If you’re relying on
undocumented/unsupported/quirky quicktime stuff, like its playback of
soundtracks with bangs, etc., you’re going to run into the trouble.

For predictable behavior, "frame 10, bang" would be necessary here.

The bang message, by the way, causes QuickTime to task, which in turn
causes it to figure out that the window moved.


Feb 22 2006 | 4:26 pm

Ok. I had the impression that there is no need to bang when
using the direct to window method.

Actually I intend to output 7 Pal movies (768*576) to seven screens attached
to a G5 Quad with 4 (twin head) Graphic cards. It seems that I can only
achieve a fluent representation of the clips when using direct to window
with NO bangs. As soon as I start to bang the clips (frame n, bang) the
clips start to stutter. Therefore I replay the clips with a very slow rate
and send the frame numbers without bangs.

Any idea how I could fix this? Is there eventually a function like "direct
to videoplane"? When I read the movie with 5040*576 Pixels and map it on a
videoplane it is all too slow.

Thanks for any hints.


Feb 22 2006 | 4:49 pm

As mentioned in previous threads, you cannot span a single window
across different ~cards~ (this completely kills your frame rate)
however you can successfully span across the 2 heads of a single
card, so it seems you could try 3 windows (two planes each) at
1536×576, and the a 4th at 768×576, optionally, you could combine 6
movies into 3 at 1536×576 to reduce the number of videoplanes required.

another option is to use one large QXGA movie containing all the pal
movies tiled, and zoom in on the content with hardware scalars. (but
by then you might as well invest in synchronized dvd players or 7
minimacs etc.

good luck Dekron


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