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Discussion Starter · #1 ·
Hello Folks,


Okay I know the horizontal scan rates for the usuall HDTV resolutions:


480p and 960i is 31.5 Khz horizontal scanrate

540p and 1080i is 33.75 Khz horizontal scanrate

720p and 1440i is 45 Khz horizontal scanrate


But what is the horizontal scanrate for 1080p/60 amd 1080p/24fps - need it in order to calculate my "modeline".


Cheers Kaninbunny
 

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67.5 kHz - twice the interlaced rate.


480p/960i would ordinarily not be termed an HD rate - some called it SD (standard), some call it ED (enhanced).
 

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Discussion Starter · #3 ·
Thanks!!


Now I'm a bit on my way creating 1080p HTPC. Hmm, okay now we know that the total number of lines should be 1125


1125=67500/60


The question is how long front porch, sync with and back porch should be? Isn't there any documentation avalible online that list all those numbers in pixels or times. (how would the HW companies otherwise be able to make thier stuff comply).


Also there is big hole in my knowledge in regards to the horizontal resolution 1920 in the 1080p 16:9 case. I don't have any figures for it. Help or pointers would be a great help.


Cheers Kaninbunny
 

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There are at least two standards that describe monitor timings:

- VESA DMT, Discrete Monitor Timing. This is just a table that lists several resolutions with several refresh rates. This is off no use for you since you do not want a standard timing.

- VESA GTF, Generalized Timing Formula. You can use this to calculate monitor timings for arbitrary resolutions/refresh rates. This is what you need.


You can download the official VESA GTF documentation for free from the VESA site but that probably does not help you.


Fortunately ScitechSoft did implement VESA GTF and a test application in their MGL library.

I have compiled the application and have put it online. You can download it here:
http://home.student.utwente.nl/r.muller/gtfcalc.zip
 

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Correct, the ATSC 1080i system is in fact a 1125 line system behind the scenes. All of the waveform details you require may be found by downloading (for a fee) the SMPTE 274M document from www.smpte.org. You can also simply look at the Powerstrip predefined HDTV custom timings.


I did not understand your question about 1920 horizontal resolution.... please clarify.
 
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