0 Replies Latest reply on Sep 6, 2009 7:59 AM by ziphnor

    Intel X4500: Video levels being expanded to PC levels

    ziphnor

      My HTPC is an Aopen MP-45DR equipped with an X4500MHD GPU. I have installed Windows 7 Ultimate on it. The newest driver for the GPU is installed. I have a few years old 1280x720 Sony 50" rear-pro LCD hdtv (KDF-E50A11) connected to it via DVI->HDMI (both video and audio passed over the HDMI connection ).

       

      When viewing the "pluge" pattern on DVE (as well as any other similar test patterns) i cannot see the blacker-than-black no matter how high i turn up the brightness on my TV. This is regardless of codec, program and video renderer used (and i tried alot, for example VLC,MCE,Mediaportal and WMP).

       

      If i view a bitmap of the PLUGE pattern (such as http://avical.com/UserFiles/Image/PLUGE-LAPL.jpg), i CAN see the blacker-than-black data with high brightness.

       

      If i take a screenshot of the playback of the DVE PLUGE pattern, and dump it into paint then i can see that the background is RGB 1,0,1 or something like that, and one of the visible bars is around 10,10,10. I was expecting 16,16,16 for the black background (ie video black).

       

      I guess that means that somewhere the video is being expanded from 16-235 into 0-255 throwing away btb and wtw, potentially screwing up my image (and at the very least making it harder to calibrate)?

       

      Btw, if i use the intel GPU driver settings to override the video brightness then i can see the btb data, further supporting the above conclusion.

       

      Question is: How do i stop this expansion of the video levels so that wtw and btb isnt lost? Most other video cards i have had either have an explicit control for choosing between 0-255 and 16-235 for video levels or manage to detect it correctly.