All,

I’m trying to set my G70 up for 1152 x 864p 75hz (for PAL 4x3), however I can’t get the RGB size wide enough to fill the screen. The internal setup grids easily fill the screen.
If I set up 1920 x 1080p @ 50, I have plenty of adjustment on the RGB size.

I’m using an HTPC to feed the G70 via RGBHV. The video card is an NVidia Quadro FX 3400. Do I need different porch or sync width setting or something?

Thanks.

Yeah, you should probably try less total pixels while holding your active pixels constant. So less porch and / or less sync.

craigr

Is your raster shooting off the sides of the tube and the image is only a tiny part of the raster?

craigr

I'll have a look. Back in a tick...

what bandwidth is 1152x864 @75Hz ??
Keep in mine the G70 has A spec't bandwidth of 120mhz and it is better to keep under that for headroom...

Cheers....

Is your raster shooting off the sides of the tube and the image is only a tiny part of the raster?

craigr

As far as I can tell, no. The active image appears to be almost as wide as the raster.

The NVidia card offers the following options (with the values I have put in (probably wrongly) gleaned from other posts as I don't know what they mean! :o )

HPix: 1152
VPix: 864
Progressive
HFP: 88
HTotal: ? Left blank
HSyncW: 44
HSyncPol: +
VFP: 4
VTotal: ? Left blank
VSyncW: 5
VSyncPol: +
Refresh rate: 75.18
It doesn't have the option to enter BP values.

what bandwidth is 1152x864 @75Hz ??
Keep in mine the G70 has A spec't bandwidth of 120mhz and it is better to keep under that for headroom...

Cheers....

Just over the 100 I think...

As far as I can tell, no. The active image appears to be almost as wide as the raster.

The NVidia card offers the following options (with the values I have put in (probably wrongly) gleaned from other posts as I don't know what they mean! :o )

HPix: 1152
VPix: 864
Progressive
HFP: 88
HTotal: ? Left blank
HSyncW: 44
HSyncPol: +
VFP: 4
VTotal: ? Left blank
VSyncW: 5
VSyncPol: +
Refresh rate: 75.18
It doesn't have the option to enter BP values.

I am no expert on HTPC's so someone may correct me, but I would think that you should specify the total pixels to help define your raster size. Try putting HTotal at around 1300 and VTotal at around 900 and see if that helps. That's what I do with stand alone video processors of which I know a great bit.

craigr

The refresh rate is off too.

It should be 75.00.


Seriously, no one should use a graphics card that doesn't support Powerstrip (it may work on a FX3400, I'm not sure).

what bandwidth is 1152x864 @75Hz ??
Keep in mine the G70 has A spec't bandwidth of 120mhz and it is better to keep under that for headroom...

Cheers....

I would ignore that completely. Marketing ********.

I just used 1:1 patterns to determine where to draw my personal line. The higher you go, the blurrier the 1920 lines get...

The refresh rate is off too.

It should be 75.00.


Seriously, no one should use a graphics card that doesn't support Powerstrip (it may work on a FX3400, I'm not sure).

It probably does but the native driver appears to have the necessary functionality built-in.
I got the 75.18 from here (being 1.5 x 50.12): http://www.pixelmagicforum.com/forum/showthread.php?t=460
Is that wrong? - I often wondered why 50.12 is "true" 50...

I am no expert on HTPC's so someone may correct me, but I would think that you should specify the total pixels to help define your raster size. Try putting HTotal at around 1300 and VTotal at around 900 and see if that helps. That's what I do with stand alone video processors of which I know a great bit.

craigr

Thanks craig, I'll try that this evening...

It probably does but the native driver appears to have the necessary functionality built-in.
I got the 75.18 from here (being 1.5 x 50.12): http://www.pixelmagicforum.com/forum/showthread.php?t=460
Is that wrong? - I often wondered why 50.12 is "true" 50...


Well, it's a new one on me. AFAIK PAL is 50.000hz. I might be wrong, but I've never heard that before.

Anyway, Bluray is where it's at, for that you want 47.952/71.928/96.905hz :)

The refresh rate is off too.

It should be 75.00.


No not nessaserally will it be spot on 75Hz, it depends on the rest of the timing parameters as you know.. Its like 1080 24p blu-rays are actually 23.97 or there abouts...

Cheers....

No not nessaserally will it be spot on 75Hz, it depends on the rest of the timing parameters as you know.. Its like 1080 24p blu-rays are actually 23.97 or there abouts...

Cheers....


Well, no, you are mixing a graphics card timing error (the fact that sometimes you can't get exactly what you want), with the fact that the refresh rate for Bluray is 24/1.001, for historical reasons.

24/1.001 = 23.9760239760239760239760239760...

I would ignore that completely. Marketing ********.

I just used 1:1 patterns to determine where to draw my personal line. The higher you go, the blurrier the 1920 lines get...I here what you are saying Mark but I would still stay well under the 120mhz bandwidth spec as leaving bandwidth head room is desirable/important for various reasons as MP has also stated....

Cheers....

Well, no, you are mixing a graphics card timing error (the fact that sometimes you can't get exactly what you want), with the fact that the refresh rate for Bluray is 24/1.001, for historical reasons.

24/1.001 = 23.9760239760239760239760239760... I dont use A PC but I totally agree what you are saying above ,But I use A highEnd VP and it gives you the source res in the config menu...

Cheers...

I dont use A PC, I use A highEnd VP and it gives you the source res in the config menu...

Cheers...

Still the same issue, a VP and a PC timings work the same way - the maths behind it is the same.

I here what you are saying Mark but I would still stay well under the 120mhz bandwidth spec as leaving bandwidth head room is desirable/important for various reasons as MP has also stated....

Cheers....

Any res worth running is pushing 120mhz..

I am no expert on HTPC's so someone may correct me, but I would think that you should specify the total pixels to help define your raster size. Try putting HTotal at around 1300 and VTotal at around 900 and see if that helps. That's what I do with stand alone video processors of which I know a great bit.

craigr

Nope - still can't get wide enough. But not to worry - I've configured 1152x864p @ 50.12 and the works a treat. No flicker with the porch and sync values mentioned and sharp as a tac!

Thanks all.

Still reckon 50.12hz is wrong..


Any flicker?

On an all white field, if there is any it's so little it's effectively none and on film - zero. :)

Interesting.

The flicker at 48 or 50 hz drives me bananas.

But I have numerous friends who aren't bothered by it at all.

Running at a refresh rate not equal to an even multiple of the source is undesirable. However, running at 50.12 Hz instead of 50 Hz probably won't make much difference to most folks.

50/50.12 is only about 0.25% different. Because of the slightly higher rate, your HTPC will have to occasionally insert an extra frame here and there. I have heard that some people are very sensitive to adding occasional frames, but at that difference I know that I personally would not notice.

Occasionally I will get line noise between a power supply, projector, and VP/HTPC. A trick I have learned to deal with this over the years is to slightly tweak the frequency of the video. Often this means that on NTSC and HD running the VP at 60 Hz instead of 59.94 Hz. This is usually enough to eliminate noise on some systems. And I have never actually noticed the added frames.

So try and get an even 50 for your PAL. But if you can't it probably isn't the end of the world.

craigr

This is so weird – the 50.12 (supposedly “true” 50) isn’t then?
I read somewhere that the .12 bit is equivalent to an extra frame every 8 seconds – why do that??? :eek:
The 50.12 comes from a supposedly knowledgeable source – so who is right???

Sadly I can’t find anything to back up the 50.12 and the site (pixelmagic) doesn’t explain why they say 50.12 is true 50 – Aaaarrrrgghh!! :rolleyes:

I think I’ll go with your 50.00 suggestion – in the absence of confirmation that 50.12 is “true” 50.

As Slartibartfast said – “I’d far rather be happy than right”. :D

Thanks again for the input.

I think the old Commodore 64 computer used "CPAL" which was 50.12 Hz instead of 50 Hz...

craigr

Or maybe I have it wrong...

craigr

Well, I've set it to 50.00 – no discernable difference. So there it stays.
Wonder what I should set for NTSC? - 60... ish...? ;)

59.940hz.

But I would send it 47.952hz to avoid 3:2 judder.

59.940hz.

But I would send it 47.952hz to avoid 3:2 judder.

What? - 60-ish NTSC at 48-ish??? :confused: