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Author Topic: Hdtv = What Pc Res?  (Read 63 times)

opjose

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Hdtv = What Pc Res?
« on: May 11, 2004, 12:56:00 PM »

CLOSE but no cigar!

480p = approximately 720x480
720p = approximately 1440x720
1080i = approximately 1680x1080 (The first number is probably larger!)

So what you saw is indeed correct.

And yes I use the X2VGA on both 19" LCD and 21" SVGA displays in ALL modes w/o problems.

The 720p mode looks damn good, and IMHO the best.

1080i displays the interlacing which causes the minute "bobbing" of the display between interlaced frames.

Most 17" LCD displays and larger can handle 720p if not 1080i.

Most decent monitors over 18" also have few problems with 720p.

The large display res is the reason why it is not really viable for most games.

The Xbox simply does not have the horsepower to handle 1080i.

Heck most PC's older than a year or more do not either!

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opjose

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Hdtv = What Pc Res?
« Reply #1 on: May 11, 2004, 07:53:00 PM »

Yeah, 720p rocks.
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brilliantdonkey

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Hdtv = What Pc Res?
« Reply #2 on: May 11, 2004, 08:08:00 PM »

480p: 720x480
720p: 1440x720
1080i: 1920x1280

I'm pretty sure these are all correct, and you don't need to correct for the 16:9 aspect ratio because HDTV standards call for a native 16:9 monitor ratio, which is why your HDTV is widescreen.

I've actually downloaded HDTV videos on my PC and these were the resolutions they came in, but they sure took a hell of a lot of CPU power to play...

The 1080i is like playing a 2 megapixel photo 30 times a second. The xbox simply isn't up to it, which is why you see so few games supporting full 1080i.

Interlaced only cuts down on vertical resolution, not horizontal, so it's only a half-reduction, not quarter, and you won't be able to notice the flicker because the scanlines in 1280 pixels are too small, unless you have some huge-ass 100 in tv.
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Mr Ed

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Hdtv = What Pc Res?
« Reply #3 on: May 13, 2004, 03:10:00 PM »

QUOTE (rabalaba @ May 11 2004, 07:13 PM)
Actually the resolutions are in a 16:9 ratio so they break down like this
480p 853x480
720p 1280x720
1080i 964x544

So as you can see 720p is the best resolution  while 1080i has a slight advantage, also it is interlaced which adds an optical illusion of twice the resolution but in actuality it is half the given value like TV (NTSC is 525i and PAL is 625i where as there real resolutions are 350x263 and 417x313 respectivly)  So even 480p has 4.43 times as many pixels as the TV NTSC counterpart which makes it look that much better.

Uh, it's this plain and simple...these are off the HDTV specification.  Your actual TV resolution may vary but these are the HDTV resolutions:

480p: 720x480
720p: 1280x720
1080i: 1920x1080

What were you thinking with 1080i being 964x544 ??  1080 isn't even in that resolution!  You gotta figue the number given is always the verticle resolution.  Even if you were trying to remove 1/2 the verticle resolution to emphasize the interlaced signal (which BTW while most TVs don't do it, 1080p is part of the HDTV standard too) you would have 1920x540.  It's not like the signal is vertically interlaced, just horizontally interlaced.  jester.gif  blink.gif
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opjose

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Hdtv = What Pc Res?
« Reply #4 on: May 13, 2004, 03:16:00 PM »

Trust the talking horse!
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rabalaba

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Hdtv = What Pc Res?
« Reply #5 on: May 13, 2004, 06:00:00 PM »

Let me clarify things a little check your monitor for its refresh rate usually by pressing the menu button.  Here is what the scanrates are

What is horizontal scanrate? Scanrate is the number of scanlines generated per second. As an example, 480p is actually 480 visible scanlines and 45 invisible scanlines (vertical blanking interval, or the "sync" interval) for a total of 525 scanlines generated per 480p refresh. There are 60 refreshes per second at 60 Hz. This means 525 scanlines times 60, equals 31500. There you go, that's 31.5 Khz horizontal scanrate.

To clear up any confusion, HDTV always uses 60 Hz vertical refresh. This is the refresh rate that I will refer to throughout this reply. For 480p, 540p, and 720p, there is no confusion - it is always 60 Hz.

1080i is all of the following:

30 full frames per second; and
60 fields per second (odd scanlines or even scanlines); and
60 vertical blanking intervals per second (60 sync signals per second).

480p - Vertical Total must equal 525 lines (on 480p capable HDTVs)
540p - Vertical Total must equal 563 lines (on 1080i capable HDTVs)
720p - Vertical Total must equal 750 lines (on 720p capable HDTVs)
960i - Vertical Total must equal 525 lines (on 480p capable HDTVs)
1080i - Vertical Total must equal 563 lines (on 1080i capable HDTVs)
1440i - Vertical Total must equal 751 lines (on 720p capable HDTVs)

This means that:
480p and 960i should use Horiz Scan Rate as close to 31.5 Khz as possible
540p and 1080i should use Horiz Scan Rate as close to 33.75 Khz as possible
720p and 1440i should use Horiz Scan Rate as close to 45.0 Khz as possible

So there you go 720p is the best resolution to use and it should show up as 45Khz on the montors menu screen so if anyone that has an x2vga would be kind enough to provide some specs like refresh rates vertical and horizontal and the resolution this would clear up and doubts any of us have as to what is the real resolution provided by this device.
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Mr Ed

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Hdtv = What Pc Res?
« Reply #6 on: May 13, 2004, 06:38:00 PM »

QUOTE (rabalaba @ May 13 2004, 06:23 PM)
Hey I'm sorry if you don't believe me but I did not make the Video formats.  NTSC signal is 4:3 ratio and it is 525i.


Uh, we were talking HDTV, which is not NTSC, but ATSC, and digital not analog... tongue.gif
QUOTE
So using your logic it should be 525ix394 but since it is interlaced that would mean it would be 263x394.  No, thats not the case check it out for yourself.

not even sure what you mean here.  I wasn't talking about analog so who cares.   cool.gif
QUOTE


In square format which is 4:3 using the National Television Standards Committee (NTSC) guidlines not mine I did not make these up...
 Since when is 4:3 square?!  4:4 and 3:3 are squares dude.   laugh.gif  
QUOTE


Analog NTSC TV 4:3 aspect ratio resolution=525i-H x 330i-V (so yes they are BOTH interlaced) but why is it 330 and not 394 such as I stated above.
Uh, because analog NTSC doesn't use square pixels.  Duh! laugh.gif  Luckily HDTV does use square pixels in all modes except 704x480.  
QUOTE
  NTSC is a broadcast Standard and most TV reproduce 480i So I leave you up to the math on this one and its not as simple as a ratio calculation.

For 480p...704 x 480 in 16:9, 640 x 480 in 4:3
For 720p...1280 x 720 in 16:9, 960 x 720 in 4:3
For 1080i...1920i x 1080i in 16:9, 1440i x 1080i in 4:3 which is equivalent to 540p in actual resolution per any given instance.

That's an interesting thought...an instance?  How long is your instance?  1/60th of a second or 1/30th of a second.  Mine is 1/30th, so I get 1080p rolleyes.gif  
QUOTE


Your question had to do with the actual device x2vga and if it probably uses 1440x1080 on you PC monitor
You're right I had missed that, because maybe 4:3 ratio would be used in that case.  Still, many newer monitors are 16:9 so maybe not a moot point
QUOTE
but it cannot make an Image of that complexity without interpolating for as the maximum resolution an xbox can put out is 1280x720.

Hey, it's a free country, you can quote all the wrong information you want.  I just don't like you crapping up the boards with wrong info.

And BTW who talks about HDTV in 4:3 mode?  I mean, sure there are 4:3 specs for HDTV, but c'mon I think it's safe to assume if someone is talking 720p or 1080i they are talking 16:9.

Oh, so just so people know I'm right, here's other sources of my info:
http://www.digitalte...vbook/ch4.shtml
http://www.semicondu...us/VIAUGLOS.pdf
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opjose

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Hdtv = What Pc Res?
« Reply #7 on: May 13, 2004, 06:42:00 PM »

Ibid!

The Horse kicks-ass.

jester.gif
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CreziB

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Hdtv = What Pc Res?
« Reply #8 on: May 19, 2004, 07:45:00 PM »

Brilliantdonkey and Mr. Ed are correct.  Because I know everything.
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Foe-hammer

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Hdtv = What Pc Res?
« Reply #9 on: May 19, 2004, 08:07:00 PM »

Mr. Ed is diffinently right, 480p = 640 x 480 (4:3), 720p = 1280 x 720 ( 16:9 widescreen), and 1080i = 1440 x 1080 (widescreen).  IMO 720p looks better than 1080i on my xbox viewed on a computer monitor via the x2vga (in 1080i the screen flickers too damn much).  
Also, when I press the menu button on my monitor, 720p reads as 1024 x 768 @ 45khz horizontal frequency, while 1080i res is 800 x 600 @ 33khz horizontal freq.  I haven't figured that one out yet, I guess it must be the closest res the monitor can affiliate the xbox's high definition res's too.?

EDIT: My understanding is computer monitors are only able to give a progressive image.  How then is 1080i possible?  I assume it is becuase it's H freq is 33khz, which is high enough for a computer monitor to recognize the signal.  I'm still a little confused though.
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rabalaba

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Hdtv = What Pc Res?
« Reply #10 on: May 22, 2004, 06:27:00 AM »

QUOTE
Also, when I press the menu button on my monitor, 720p reads as 1024 x 768 @ 45khz horizontal frequency, while 1080i res is 800 x 600 @ 33khz horizontal freq. I haven't figured that one out yet, I guess it must be the closest res the monitor can affiliate the xbox's high definition res's too.?


Which coincides with what I said last week
QUOTE
This means that:
480p and 960i should use Horiz Scan Rate as close to 31.5 Khz as possible
540p and 1080i should use Horiz Scan Rate as close to 33.75 Khz as possible
720p and 1440i should use Horiz Scan Rate as close to 45.0 Khz as possible

So there you go 720p is the best resolution to use and it should show up as 45Khz on the montors menu screen so if anyone that has an x2vga would be kind enough to provide some specs like refresh rates vertical and horizontal and the resolution this would clear up and doubts any of us have as to what is the real resolution provided by this device


So like is said 1000 times before 720p is the best for the x2vga purpose, I am aware of the possibility for 1080i to look better but you are comparing apples to oranges.  1080i is more like 540p in this case so it is inferior to 720p.
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Joshua Wood

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Hdtv = What Pc Res?
« Reply #11 on: May 22, 2004, 11:39:00 PM »

Ok, got my x2vga, tis great. Another quick question - some 480p games take the whole screen, while a lot of others have a bit of a black strip down each side, usually bigger on the left. Why?

Soul Calibur 2 in 720p, and House of the Dead 3 in 480p are smaller, not using the whole screen - it's like changing the res on an LCD monitor, since the pixels are a discrete size, it doesn't stretch the image. Again, why? Since I have a regular CRT monitor, shouldn't it stretch the image to use the full screen?
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Foe-hammer

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Hdtv = What Pc Res?
« Reply #12 on: May 23, 2004, 09:24:00 AM »

QUOTE (rabalaba @ May 22 2004, 03:27 PM)
Foe-hammer Said

Which coincides with what I said last week


So like is said 1000 times before 720p is the best for the x2vga purpose, I am aware of the possibility for 1080i to look better but you are comparing apples to oranges.  1080i is more like 540p in this case so it is inferior to 720p.

Also, all the xbox resolutions (with exception of of 480i), have a vertical freq at 60hz; only the horizontal freq differs among the different res's.
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