[Gridflow-dev] 924 by 576 ?

Mathieu Bouchard matju at artengine.ca
Wed Jan 31 15:58:36 EST 2007

There are some BrookTree-878 cards at University of Ottawa that say that 
they are configured as 924 columns 576 rows, and that at once say that 
they max at 480 rows and 768 columns. Somehow, GridFlow 0.8.4 doesn't 
mind, it tries to configure them, the driver reports a failure, and 
reports again that it's doing 924 columns and 576 rows, and yet GridFlow 
successfully can receive images of the requested size. Now, I have two 
BrookTree-878 at home and as well as one BrookTree-849 and none of the 
three exhibit that rather peculiar behaviour, so I have to SSH/X11 at 
University of Ottawa to test those video digitisers that are supposed to 
be the same that I have.

Some hints:
   768*480 is 8:5 NTSC.
   720*480 is 3:2 NTSC (DV).
   640*480 is 4:3 NTSC (VGA).
   720*576 is 5:4 PAL.
   921.6*576 is 8:5 PAL.

921.6 is rounded by the driver to 924 because 924 is a multiple of 12 
(well, presumably just because it's a multiple of 4... i can't believe 
that the driver needs it to be a multiple of 3).

GridFlow tries to set the size to 720 columns 480 rows and fails. Then, 
the preset button tries to set the size to 320 columns 240 rows and fails 

Anyone can explain that mystery? Because GridFlow 0.9.0 tries to listen 
more to what the driver says, and ironically, that might be what prevents 
it from working.

  _ _ __ ___ _____ ________ _____________ _____________________ ...
| Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
| Freelance Digital Arts Engineer, Montréal QC Canada

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