QuickTime content, gamma and Graphics modes, some notes

rodney tamblyn rodney at infiny.co.nz
Mon Mar 15 00:41:33 EST 2004


I had a quicktime movie which displays perfectly on Mac, but on Windows  
appears "greyed out" - any white areas in the movie appear grey, and  
the video areas appear several shades darker than they do on the Mac.   
At first I thought this was a Revolution issue - because if I set the  
alwaysbuffer of the movie to true then the movie displayed correctly.   
However opening the movie in QuickTime Player I observed the same  
problem.  The issue appears to be related to the graphics mode of the  
video track in the movie itself.   To fix this you will need to have a  
copy of QuickTime Pro.  Open the movie, get properties, select the  
video track, and choose "Graphics Mode" from the properties list.   
Change the move from dither to composition (dither copy).  I worked  
this out for myself, however a bit of searching on the net  shows that  
others have run into it in the past as well, see for example:
http://listserv.uark.edu/scripts/wa.exe?A2=ind0401c&L=direct- 
l&F=&S=&P=28592
(This writer recommends saving as stand alone, but I didn't find this  
to be necessary)

A related issue is differences in gamma levels between Mac and Windows.  
  I've found that adjusting the gamma settings in the Display control  
panel (Settings ->Advanced) on the PC can make a huge impact on the  
display of QuickTime content.  Depending on your application you may  
wish to advise users to check/adjust these settings.

- Rodney

--
Rodney Tamblyn
44 Melville Street
Dunedin
New Zealand
+64 3 4778606
http://rodney.weblogs.com/



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