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Discussion Starter · #1 ·
Hi:


I'm rather new to the HTPC scene and I was hoping that some of the more experienced forum members might educate me a little more on the fine points of doing computer resolutions within higher HDTV supported resolutions. I've read Marks excellent DEFINITIVE GUIDE: Displaying Custom Resolutions on HDTV!


To put this in perspective, here's what I am trying to do that prompts my curiosity about these letterboxed" resolutions:


I have a first generation 4:3 Mits HDTV that compresses the raster vertically to create a 16:9 display for HD signals (540p and 1080i). It is also possible to go into the service mode and change the HD inputs to accept 480p signals. When this is done and a 640x480 signal is applied to the HD inputs HDTV uses the full 4:3 screen to display the image. (Doing this should provide me with an excellent 60" Windows desktop.) I assume these service changes are changing the fixed horizontal scan rate from 33.75 khz to 31.5 khz.


After setting up my HDTV to accept 480p signals I have tried to use my HTPC to send it a 640x480 windows desktop as an experiment. The result was that the image would not sync at 480p, but I found it would display as a letterboxed image within the 16:9 raster after I returned my settings to HD.


Since I selected one of Power Strip's preset HDTV derived resolutions, I am wondering whether I really wasn't sending a true 480p signal to the HDTV when it was expecting a 31.5 khz horizontal scan rate, but rather a higher resolution 33.75 khz, 1080i signal.


Does this seem plausible to explain why the signal would not sync?


If so, how would I go about setting up a custom standard 640x480 resolution?


Thanks.


Larry
 

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The 640x480 HDTV derived is actually running at 540p timings, ~33.75 KHz horizontal & 60 Hz vertical. I know this because I created it for the purpose of having 640x480p without having to flip the dip switch on the Key Digital transcoder. Use the standard Windows 640x480p instead.

For more info read this thread: http://www.avsforum.com/ubb/Forum12/HTML/007647.html


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Wayne Harrelson

Springfield, Va
http://www.geocities.com/wayneharrel...HTPC_Page.html

http://www.mp3.com/karnis




[This message has been edited by Karnis (edited 05-10-2001).]
 

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Discussion Starter · #3 ·
Quote:
Originally posted by Karnis:
...Use the standard Windows 640x480p instead.

Wayne:


Thanks for confirming my suspicions, and by the way thanks for all the work you've done with PowerStrip's custom resolutions. I believe all the resolutions that I'm using on my HTPC are your HDTV derived creations.


I hope you don't mind a few more newbie questions.


I don't have access to PowerStrip right now, but I'm pretty sure that the predefined Custom Resolutions on my version do not include any standard 640x480 resolutions. Is there an easy way to select them in PowerStrip versus building them from scratch?


Is it the total number of lines that determines whether it is a standard resolution or a letterboxed resolution?


In other words, a 640x480 resolution with 540p timings would have 563 total lines and a 640x480 resolution with standard timings would have 525 total lines?


Thanks.


Larry
 

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Quote:
Originally posted by LarryChanin:

I don't have access to PowerStrip right now, but I'm pretty sure that the predefined Custom Resolutions on my version do not include any standard 640x480 resolutions. Is there an easy way to select them in PowerStrip versus building them from scratch?


>>>>For 640x480p on your HDTV you don't need a custom resolution. Just use Windows default 640x480p.


In other words, a 640x480 resolution with 540p timings would have 563 total lines and a 640x480 resolution with standard timings would have 525 total lines?


>>>>Yes.


Thanks.


Larry[/b]



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Wayne Harrelson

Springfield, Va
http://www.geocities.com/wayneharrel...HTPC_Page.html

http://www.mp3.com/karnis
 
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