Microsoft Engineer Demystifies 1080p

Razor05 · 10-23-2006, 06:41 PM

As per TeamXbox:

Microsoft Engineer Demystifies 1080p
By: César A. Berardini - "Cesar"
Oct. 23rd, 2006 8:21 am
Andre Vrignaud, Microsoft’s director of technical strategy for Xbox Live, has updated his personal blog with an interesting clarification on 1080p visuals. With the upcoming Fall update to the Xbox 360 dashboard, Microsoft’s next-gen console will also be able to run visuals at 1080p resolution, just like Sony’s PlayStation 3 does.

Because of all this 1080p chitchat, Vrignaud decided to contact Bruce Dawson, a senior software engineer at Microsoft, who was kind enough to provide some information to demystify the benefits and tradeoffs of running game at 1080p or like Sony likes to call it, True HD.

The entire post @Ozymandias.com:

Clarifying Thoughts on High Definition Game Rendering
I was talking to Bruce Dawson, one of our senior software design engineers here, about some questions I had around 1080i and 1080p. Frankly, I was particularly curious about why Sony has continued harping on 1080p as being "TrueHD", especially since the 360 has enabled 1080p output as well (coming soon to homes near you!) I was trying to figure out if I was just missing something, and his emailed answer was particularly clear and helpful to me, and since there's nothing confidential here I thought I'd share it with you.

The really interesting statistic that popped for me is how much less time a game console has to render a 1920x1080 scene versus a 1280x720 scene. (Remember this is on the same console, whichever one you like. This is not a comparison of different console's rendering capabilities to each other.) Simply put, for a 1080i/p game the console has 55% less time per pixel to render any special effects, anti-aliasing, illumination, etc. than for a 720p game. Yes, even Resistance has fallen off the bandwagon and admitted they can't hit 1080i/p as previously claimed. (It also helps explain why Gran Turismo HD is so underwhelming.)

Anyway, Bruce's text is below. Hope it helps clarify a few things for you!

Many developers, gamers, and journalists are confused by 1080p. They think that 1080p is somehow more challenging for game developers than 1080i, and they forget that 1080 (i or p) requires significant tradeoffs compared to 720p. Some facts to remember:

2.25x: that’s how many more pixels there are in 1920x1080compared to 1280x720
55.5%: that’s how much less time you have to spend on each pixel when rendering 1920x1080 compared to 1280x720—the point being that at higher resolutions you have more pixels, but they necessarily can’t look as good
1.0x: that’s how much harder it is for a game engine to render a game in 1080p as compared to 1080i—the number of pixels is identical so the cost is identical
There is no such thing as a 1080p frame buffer. The frame buffer is 1080 pixels tall (and presumably 1920 wide) regardless of whether it is ultimately sent to the TV as an interlaced or as a progressive signal.
1280x720 with 4x AA will generally look better than 1920x1080 with no anti-aliasing (there are more total samples).
A few elaborations:

Any game could be made to run at 1920x1080. However, it is a tradeoff. It means that you can show more detail (although you need larger textures and models to really get this benefit) but it means that you have much less time to run complex pixel shaders. Most games can’t justify running at higher than 1280x720—it would actually make them look worse because of the compromises they will have to make in other areas.

1080p is a higher bandwidth connection from the frame buffer to the TV than 1080i. However the frame buffer itself is identical. 1080p will look better than 1080i—interlaced flicker is not a good thing—but it makes precisely zero difference to the game developer. Just as most Xbox 1 games let users choose 480i or 480p, because it was no extra work, 1080p versus 1080i is no extra work. It’s just different settings on the display chip.

Inevitably somebody will ask about field rendering. Since interlaced formats display the even lines on one refresh pass and then the odd lines on the next refresh pass, can’t games just render half of the lines each time? Probably not, and even if you could you wouldn’t want to. You probably can’t do field rendering because it requires that you maintain a rock solid 60 fps. If you ever miss a frame it will look horrible, as the odd lines are displayed in place of the even, or vice-versa. This is a significant challenge when rendering extremely complex worlds with over 1 million pixels per field (2 million pixels per frame) and is probably not worth it. And, even if you can, you shouldn’t. The biggest problem with interlaced is flicker, and field rendering makes it worse, because it disables the ‘flicker fixer’ hardware that intelligently blends adjacent lines. Field rendering has been done in the past, but it was always a compromise solution.

crellion · 10-23-2006, 07:25 PM

Wait a sec - this doesn't make any sense. Are you saying that if I set my 360 to 1080i - I get lower shader performance and lower framerates? I thought the 360 ran 1080i and 720p exactly same performance and quality?!!!

Joe_news · 10-24-2006, 12:14 AM

This is why analogy's are our friends ppl!

GLOW · 10-24-2006, 08:43 AM

Quote:

Originally Posted by Razor05

the point being that at higher resolutions you have more pixels, but they necessarily can’t look as good

huh?

So, is this the same with 480p vs 720p? The extra pixels can't look as good? Then why the hell are we gaming in high-def? I guess Gears of War is going to suck because it's 1080i, someone should have told Epic that extra pixels don't look as good.

alra111 · 10-24-2006, 10:22 AM

Quote:

Originally Posted by Razor05

I was talking to Bruce Dawson, one of our senior software design engineers here, about some questions I had around 1080i and 1080p. Frankly, I was particularly curious about why Sony has continued harping on 1080p as being "TrueHD", especially since the 360 has enabled 1080p output as well (coming soon to homes near you!) I was trying to figure out if I was just missing something, and his emailed answer was particularly clear and helpful to me, and since there's nothing confidential here I thought I'd share it with you.

Can someone fill me in on this?

How will the 360 output 1080p? Through a VGA adapter? 1080p can't be sent via the component video output, correct?

How do I get my 360 to output 1080p? Will I be downloading a firmware update?

Thanks,
Alra111

Bigloww · 10-24-2006, 10:32 AM

I think it is more a comparrason to 1080i vs 1080p than 720p vs 1080p. Kinda like the comparison to 480i vs 480p. I guess, my head is still spinnin..

Yes, you can download the firmware when it comes out soon via XBox live. I believe you will need the VGA cable and a 1080p set with VGA/PC to utilize 1080p however..

Razor05 · 10-28-2006, 12:07 PM

Quote:

Originally Posted by GLOW

Quote:

Originally Posted by Razor05

the point being that at higher resolutions you have more pixels, but they necessarily can’t look as good

huh?

So, is this the same with 480p vs 720p? The extra pixels can't look as good? Then why the hell are we gaming in high-def? I guess Gears of War is going to suck because it's 1080i, someone should have told Epic that extra pixels don't look as good.

Huh? lol, I never said that.

bf360 · 10-28-2006, 07:21 PM

i understand about how 1080p games wouldnt look as good, but i think
people will understand that but the main reason i want 1080p is for the new hd dvd adapter and couldnt microsoft just release a hdmi cable for the xbox 360?

ChaosMan1014 · 10-28-2006, 07:33 PM

Only if the redesigned the 360 to include an HDMI port.

Razor05 · 10-28-2006, 07:41 PM

Quote:

Originally Posted by bf360

i understand about how 1080p games wouldnt look as good, but i think
people will understand that but the main reason i want 1080p is for the new hd dvd adapter and couldnt microsoft just release a hdmi cable for the xbox 360?

Yeah I'm not sure if they could add HDMI on to the end of the existing AV cable they have.

10-23-2006, 06:41 PM	#1
Razor05 HD = 65 beautiful inches Join Date: Jun 2005 Location: Canada Posts: 3,296	Microsoft Engineer Demystifies 1080p As per TeamXbox: Microsoft Engineer Demystifies 1080p By: César A. Berardini - "Cesar" Oct. 23rd, 2006 8:21 am Andre Vrignaud, Microsoft’s director of technical strategy for Xbox Live, has updated his personal blog with an interesting clarification on 1080p visuals. With the upcoming Fall update to the Xbox 360 dashboard, Microsoft’s next-gen console will also be able to run visuals at 1080p resolution, just like Sony’s PlayStation 3 does. Because of all this 1080p chitchat, Vrignaud decided to contact Bruce Dawson, a senior software engineer at Microsoft, who was kind enough to provide some information to demystify the benefits and tradeoffs of running game at 1080p or like Sony likes to call it, True HD. The entire post @Ozymandias.com: Clarifying Thoughts on High Definition Game Rendering I was talking to Bruce Dawson, one of our senior software design engineers here, about some questions I had around 1080i and 1080p. Frankly, I was particularly curious about why Sony has continued harping on 1080p as being "TrueHD", especially since the 360 has enabled 1080p output as well (coming soon to homes near you!) I was trying to figure out if I was just missing something, and his emailed answer was particularly clear and helpful to me, and since there's nothing confidential here I thought I'd share it with you. The really interesting statistic that popped for me is how much less time a game console has to render a 1920x1080 scene versus a 1280x720 scene. (Remember this is on the same console, whichever one you like. This is not a comparison of different console's rendering capabilities to each other.) Simply put, for a 1080i/p game the console has 55% less time per pixel to render any special effects, anti-aliasing, illumination, etc. than for a 720p game. Yes, even Resistance has fallen off the bandwagon and admitted they can't hit 1080i/p as previously claimed. (It also helps explain why Gran Turismo HD is so underwhelming.) Anyway, Bruce's text is below. Hope it helps clarify a few things for you! Many developers, gamers, and journalists are confused by 1080p. They think that 1080p is somehow more challenging for game developers than 1080i, and they forget that 1080 (i or p) requires significant tradeoffs compared to 720p. Some facts to remember: 2.25x: that’s how many more pixels there are in 1920x1080compared to 1280x720 55.5%: that’s how much less time you have to spend on each pixel when rendering 1920x1080 compared to 1280x720—the point being that at higher resolutions you have more pixels, but they necessarily can’t look as good 1.0x: that’s how much harder it is for a game engine to render a game in 1080p as compared to 1080i—the number of pixels is identical so the cost is identical There is no such thing as a 1080p frame buffer. The frame buffer is 1080 pixels tall (and presumably 1920 wide) regardless of whether it is ultimately sent to the TV as an interlaced or as a progressive signal. 1280x720 with 4x AA will generally look better than 1920x1080 with no anti-aliasing (there are more total samples). A few elaborations: Any game could be made to run at 1920x1080. However, it is a tradeoff. It means that you can show more detail (although you need larger textures and models to really get this benefit) but it means that you have much less time to run complex pixel shaders. Most games can’t justify running at higher than 1280x720—it would actually make them look worse because of the compromises they will have to make in other areas. 1080p is a higher bandwidth connection from the frame buffer to the TV than 1080i. However the frame buffer itself is identical. 1080p will look better than 1080i—interlaced flicker is not a good thing—but it makes precisely zero difference to the game developer. Just as most Xbox 1 games let users choose 480i or 480p, because it was no extra work, 1080p versus 1080i is no extra work. It’s just different settings on the display chip. Inevitably somebody will ask about field rendering. Since interlaced formats display the even lines on one refresh pass and then the odd lines on the next refresh pass, can’t games just render half of the lines each time? Probably not, and even if you could you wouldn’t want to. You probably can’t do field rendering because it requires that you maintain a rock solid 60 fps. If you ever miss a frame it will look horrible, as the odd lines are displayed in place of the even, or vice-versa. This is a significant challenge when rendering extremely complex worlds with over 1 million pixels per field (2 million pixels per frame) and is probably not worth it. And, even if you can, you shouldn’t. The biggest problem with interlaced is flicker, and field rendering makes it worse, because it disables the ‘flicker fixer’ hardware that intelligently blends adjacent lines. Field rendering has been done in the past, but it was always a compromise solution. __________________ Panasonic TH-65PZ850U Sony KDL37XBR6 Panasonic TH-37PX50U Cambridge Audio Azur 640R & 740C Paradigm Studio 60's, 20's, CC-590 & Seismic 12 Panasonic DMP-BD35 Toshiba HD-XA2 & A35 Motorola VIP1200 Monster HTFS1000, PB2100 AA 1154a MW2 LE Xbox 360 & Halo3 LE + HD-DVD GT: Razor59 Sony PS3 slim GT:Razor_59 Sony PSP

10-28-2006, 07:33 PM	#9
ChaosMan1014 Scrumdidlyumptious Join Date: Dec 2005 Posts: 927	Only if the redesigned the 360 to include an HDMI port. __________________ PSN ID: LordVierge If only we could develop a real Katamari... It would be the ultimate globe conquering tool!

10-23-2006, 07:25 PM	#2
crellion High Definition is the definition of life. Join Date: Aug 2005 Posts: 154	Wait a sec - this doesn't make any sense. Are you saying that if I set my 360 to 1080i - I get lower shader performance and lower framerates? I thought the 360 ran 1080i and 720p exactly same performance and quality?!!!

10-24-2006, 12:14 AM	#3
Joe_news Sega does what Nintendont Join Date: Oct 2006 Location: U.S. of A. Posts: 951	This is why analogy's are our friends ppl!

10-24-2006, 10:32 AM	#6
Bigloww Chi Town Baby.. Da Bears. Join Date: Apr 2006 Location: In a van, down by the river. Posts: 5,130	I think it is more a comparrason to 1080i vs 1080p than 720p vs 1080p. Kinda like the comparison to 480i vs 480p. I guess, my head is still spinnin.. Yes, you can download the firmware when it comes out soon via XBox live. I believe you will need the VGA cable and a 1080p set with VGA/PC to utilize 1080p however..

10-28-2006, 07:21 PM	#8
bf360 Bring it on Join Date: Oct 2006 Location: Jersey Posts: 133	i understand about how 1080p games wouldnt look as good, but i think people will understand that but the main reason i want 1080p is for the new hd dvd adapter and couldnt microsoft just release a hdmi cable for the xbox 360?