[mythtv-users] (OT) Easy 'realtime' Modeline generator?

junk_inbox at comcast.net junk_inbox at comcast.net
Tue Mar 8 22:33:00 UTC 2005


I just hooked my frontend box up to my very old Sony CRT Video Projector (Circa 1986) via VGA and a special modeline to generate 15khz output (768x483 @ 59.94Hz Interlaced).  I had to use an old Matrox video card that would sync down to 15khz and generate Composite sync.  Here's the modeline I'm currently using that works pretty well (other than having the left and right sides of the display chopped of by roughly 10 pixels): 
   ModeLine "NTSCspec-59.94i" 14.318 768 784 848 910 483 484 492 525 Interlace -CSYNC

Again, it's working fine, but this modeline is 14.318Khz, and my projector is capable of scanning up to 26Khz.  I'd like to optimize the display mode to take advantage of this, and hopefully eliminate most of the interlace flicker.

So I tried different Modeline settings, and it was a real pain to test different modes as restarting X didn't seem to take the new modeline, so I would have to re-boot inbetween changes.  And if the modeline wasn't right, then X would fail to load and I would have to connect a standard 'vga' monitor to display the text mode display (which is 31khz scan rate) so I can edit the config file to try a different modeline.  Then I re-boot again with the projector connected to try it out... After about 20 attempts at different mode lines and having very limited success, I decided I'd just have to live with the 15khz mode for now.  (Note: I was using a couple of online modeline calculators on my Laptop to generate modelines that I was trying on the Linux box, not just randomly trying different settings!)

So as my subject line asks...  Is there a 'realtime' modeline tool (similar to "PowerStrip" for the PC) for Linux?  You know, something that you can select different resolutions and adjust things dynamically, and hit 'esc' to revert to a 'working' display if you end up with an unusable display?  Or do I have to use a PC and PowerStrip to determine what works best with my projector, and then generate a modeline from PowerStrip?

If it makes any difference, the frontend box is a P4 @ 800Mhz running FC3, and the Projector is a Sony VPH-1030Q1 with the following specs:
  VPH-1030Q  (Low serial# 50xxxxx - only up to 26KHz) 
  Lumens: 500  
  Contrast Ratio: 15,000:1  
  Horizontal Scanrate: 15-26KHz 
  Vertical Scanrate: 50-100Hz
  RGB Bandwidth: 15MHz
  Composite Sync

Thanks in advance... 

Jeff



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